Wednesday Jan 09, 2013

How to Treat an NFS File As a Block Storage Device

source

Wim actually beat me in blogging about this feature while I was on vacation, but I'd like to add a little more background about dm-nfs, which I gathered from our kernel developers:

What is dm-nfs?

The dm-nfs kernel module provides a device-mapper target that allows you to treat an NFS file as a block device. It provides loopback-style emulation of a block device using a regular file as backing storage. The backing file resides on a remote system and is accessed via the NFS protocol.

The general idea is to have a more-efficient-than-loop access to files on NFS. The device mapper module directly converts requests to the dm device into NFS RPC calls.

dm-nfs is used transparently by Oracle VM's Dom0 when mounting NFS-backed virtual disks. It essentially allows for asynchronous and direct I/O to an NFS-backed block device, which is a lot faster than normal NFS for virtual disks. The Xen block hotplug script has been modified on OVM to look for files which are on NFS filesystems. If the file is on NFS, OVM uses dm-nfs automatically, otherwise it falls back to using the regular (but slower) loop mount method.

The original dm-nfs module was written by Chuck Lever. It has been supported and used by Oracle VM since version 2.2 and is also included in the Unbreakable Enterprise Kernel for Oracle Linux.

Why this feature matters

This feature creates virtual disk devices (LUNs) where the data is stored in an NFS file instead of on local storage. Managed networked storage has many benefits over keeping virtual devices on a disk local to the physical host.

A sample use case is the fast migration of guest VMs for load balancing or if a physical host requires maintenance. This functionality is also possible using iSCSI LUNs, but the advantage of dm-nfs is that you can manage new virtual drives on a local host system, rather than requiring a storage administrator to initialize new LUNs on the storage subsystem. Host administrators can handle their own virtual disk provisioning.

For durability and performance, dm-nfs uses asynchronous and direct I/O so all I/O operations are performed efficiently and coherently. Guest disk data is not double cached on the underlying host. If the underlying host crashes, there's a lower probability of data corruption. If the guest is frozen, a clean backup can be taken of the virtual disk, as you can be certain that its data has been fully written out.

How to use it

You use dm-nfs by first loading the kernel module, then using dmsetup to create a device mapper device on your file. The syntax is very similar to the dm-linear module.

The following sample code demonstrates how to use dmsetup to create a mapped device (/dev/mapper/$dm_nfsdev) for the file $filename that is accessible on a mounted NFS file system:

nblks=`stat -c '%s' $filename`
echo -n "0 $nblks nfs $filename 0" | dmsetup create $dm_nfsdev

Now you can mount /dev/mapper/$dm_nfsdev like any other filesystem image.

- Lenz Grimmer (Oracle Linux Blog)

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Wednesday Aug 15, 2012

It's Better with Btrfs

source

Two recently published articles to help you become proficient with the Btrfs file system in Oracle Linux:

How I Got Started with the Btrfs File System in Oracle Linux

By Margaret Bierman

Scalability and volume management. Write methodology and access. Tunables. Margaret describes these capabilities of the Btrfs file system, plus how it deals with redundant configurations, checksums, fault isolation and much more. She also walks you through the steps to create and set up a Btrfs file system so you can become familiar with it.

How I Use the Advanced Features of the Btrfs File System

By Margaret Bierman

How to create and mount a Btrfs file system. How to copy and delete files. How to create and manage a redundant file system configuration. How to check the integrity of the file system and its remaining capacity. How to take snapshots. How to clone. And more. In this article Margaret explores the more advanced features of the Btrfs file system.

Let us know what you think, and what you'd like to see Margaret write about in the future.

- Rick

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Tuesday Jul 17, 2012

How to Protect Your Oracle Linux System from the Higgs Boson

Now that the Higgs Boson particle has been gently coaxed out of hiding, you know what's gonna happen, don't you? Your boss is gonna walk into your office and demand a plan for protecting your Oracle Linux system against it.

You could act like a smart aleck sysadmin and inform him or her that it took a team of scientists 10 years and 500 trillion collisions to get conclusive evidence of its existence, and let's not even talk about how difficult it was for God to create the elusive thing, but that would violate the first law of corporate survival:

Never, ever make your boss look stupid

Instead, jump out of your chair and say "OMG! I hadn't though of that!" Then read our latest article and use what you learn to write up a plan that will make your boss look real good to his or her boss. (Just make sure your name appears nowhere.)

Tips for Hardening an Oracle Linux Server

Lenz Grimmer and James Morris provide guidelines for:

  • Minimizing the software footprint
  • Minimizing active services
  • Locking down network services
  • Disabling or tightening use of SSH
  • Configuring mounts, file permissions, and ownerships
  • Managing Users and Authentication
  • Other Security Features and Tools
  • Cryptography
I hope you enjoy reading the article as much as I did. And good luck with your career.

- Rick

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Friday Mar 23, 2012

How to subscribe to the free Oracle Linux errata yum repositories

Now that updates and errata for Oracle Linux are available for free (both as in beer and freedom), here's a quick HOWTO on how to subscribe your Oracle Linux system to the newly added yum repositories on our public yum server, assuming that you just installed Oracle Linux from scratch, e.g. by using the installation media (ISO images) available from the Oracle Software Delivery Cloud

You need to download the appropriate yum repository configuration file from the public yum server and install it in the yum repository directory. For Oracle Linux 6, the process would look as follows: as the root user, run the following command:

[root@oraclelinux62 ~]# wget http://public-yum.oracle.com/public-yum-ol6.repo \
-P /etc/yum.repos.d/
--2012-03-23 00:18:25--  http://public-yum.oracle.com/public-yum-ol6.repo
Resolving public-yum.oracle.com... 141.146.44.34
Connecting to public-yum.oracle.com|141.146.44.34|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1461 (1.4K) [text/plain]
Saving to: “/etc/yum.repos.d/public-yum-ol6.repo”

100%[=================================================>] 1,461       --.-K/s   in 0s      

2012-03-23 00:18:26 (37.1 MB/s) - “/etc/yum.repos.d/public-yum-ol6.repo” saved [1461/1461]
For Oracle Linux 5, the file name would be public-yum-ol5.repo in the URL above instead. The "_latest" repositories that contain the errata packages are already enabled by default — you can simply pull in all available updates by running "yum update" next:
[root@oraclelinux62 ~]# yum update
Loaded plugins: refresh-packagekit, security
ol6_latest                                                    | 1.1 kB     00:00     
ol6_latest/primary                                            |  15 MB     00:42     
ol6_latest                                                               14643/14643
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package at.x86_64 0:3.1.10-43.el6 will be updated
---> Package at.x86_64 0:3.1.10-43.el6_2.1 will be an update
---> Package autofs.x86_64 1:5.0.5-39.el6 will be updated
---> Package autofs.x86_64 1:5.0.5-39.el6_2.1 will be an update
---> Package bind-libs.x86_64 32:9.7.3-8.P3.el6 will be updated
---> Package bind-libs.x86_64 32:9.7.3-8.P3.el6_2.2 will be an update
---> Package bind-utils.x86_64 32:9.7.3-8.P3.el6 will be updated
---> Package bind-utils.x86_64 32:9.7.3-8.P3.el6_2.2 will be an update
---> Package cvs.x86_64 0:1.11.23-11.el6_0.1 will be updated
---> Package cvs.x86_64 0:1.11.23-11.el6_2.1 will be an update

[...]

---> Package yum.noarch 0:3.2.29-22.0.1.el6 will be updated
---> Package yum.noarch 0:3.2.29-22.0.2.el6_2.2 will be an update
---> Package yum-plugin-security.noarch 0:1.1.30-10.el6 will be updated
---> Package yum-plugin-security.noarch 0:1.1.30-10.0.1.el6 will be an update
---> Package yum-utils.noarch 0:1.1.30-10.el6 will be updated
---> Package yum-utils.noarch 0:1.1.30-10.0.1.el6 will be an update
--> Finished Dependency Resolution

Dependencies Resolved

=====================================================================================
 Package                     Arch    Version                       Repository   Size
=====================================================================================
Installing:
 kernel                      x86_64  2.6.32-220.7.1.el6            ol6_latest   24 M
 kernel-uek                  x86_64  2.6.32-300.11.1.el6uek        ol6_latest   21 M
 kernel-uek-devel            x86_64  2.6.32-300.11.1.el6uek        ol6_latest  6.3 M
Updating:
 at                          x86_64  3.1.10-43.el6_2.1             ol6_latest   60 k
 autofs                      x86_64  1:5.0.5-39.el6_2.1            ol6_latest  470 k
 bind-libs                   x86_64  32:9.7.3-8.P3.el6_2.2         ol6_latest  839 k
 bind-utils                  x86_64  32:9.7.3-8.P3.el6_2.2         ol6_latest  178 k
 cvs                         x86_64  1.11.23-11.el6_2.1            ol6_latest  711 k

[...]

 xulrunner                   x86_64  10.0.3-1.0.1.el6_2            ol6_latest   12 M
 yelp                        x86_64  2.28.1-13.el6_2               ol6_latest  778 k
 yum                         noarch  3.2.29-22.0.2.el6_2.2         ol6_latest  987 k
 yum-plugin-security         noarch  1.1.30-10.0.1.el6             ol6_latest   36 k
 yum-utils                   noarch  1.1.30-10.0.1.el6             ol6_latest   94 k

Transaction Summary
=====================================================================================
Install       3 Package(s)
Upgrade      96 Package(s)

Total download size: 173 M
Is this ok [y/N]: y
Downloading Packages:
(1/99): at-3.1.10-43.el6_2.1.x86_64.rpm                       |  60 kB     00:00     
(2/99): autofs-5.0.5-39.el6_2.1.x86_64.rpm                    | 470 kB     00:01     
(3/99): bind-libs-9.7.3-8.P3.el6_2.2.x86_64.rpm               | 839 kB     00:02     
(4/99): bind-utils-9.7.3-8.P3.el6_2.2.x86_64.rpm              | 178 kB     00:00     

[...]

(96/99): yelp-2.28.1-13.el6_2.x86_64.rpm                      | 778 kB     00:02     
(97/99): yum-3.2.29-22.0.2.el6_2.2.noarch.rpm                 | 987 kB     00:03     
(98/99): yum-plugin-security-1.1.30-10.0.1.el6.noarch.rpm     |  36 kB     00:00     
(99/99): yum-utils-1.1.30-10.0.1.el6.noarch.rpm               |  94 kB     00:00     
-------------------------------------------------------------------------------------
Total                                                306 kB/s | 173 MB     09:38     
warning: rpmts_HdrFromFdno: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY
Retrieving key from http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6
Importing GPG key 0xEC551F03:
 Userid: "Oracle OSS group (Open Source Software group) "
 From  : http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6
Is this ok [y/N]: y
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Updating   : yum-3.2.29-22.0.2.el6_2.2.noarch                                1/195 
  Updating   : xorg-x11-server-common-1.10.4-6.el6_2.3.x86_64                  2/195 
  Updating   : kernel-uek-headers-2.6.32-300.11.1.el6uek.x86_64                3/195 
  Updating   : 12:dhcp-common-4.1.1-25.P1.el6_2.1.x86_64                       4/195 
  Updating   : tzdata-java-2011n-2.el6.noarch                                  5/195 
  Updating   : tzdata-2011n-2.el6.noarch                                       6/195 
  Updating   : glibc-common-2.12-1.47.el6_2.9.x86_64                           7/195 
  Updating   : glibc-2.12-1.47.el6_2.9.x86_64                                  8/195 

[...]

  Cleanup    : kernel-firmware-2.6.32-220.el6.noarch                         191/195 
  Cleanup    : kernel-uek-firmware-2.6.32-300.3.1.el6uek.noarch              192/195 
  Cleanup    : glibc-common-2.12-1.47.el6.x86_64                             193/195 
  Cleanup    : glibc-2.12-1.47.el6.x86_64                                    194/195 
  Cleanup    : tzdata-2011l-4.el6.noarch                                     195/195 

Installed:
  kernel.x86_64 0:2.6.32-220.7.1.el6                                                 
  kernel-uek.x86_64 0:2.6.32-300.11.1.el6uek                                         
  kernel-uek-devel.x86_64 0:2.6.32-300.11.1.el6uek                                   

Updated:
  at.x86_64 0:3.1.10-43.el6_2.1                                                      
  autofs.x86_64 1:5.0.5-39.el6_2.1                                                   
  bind-libs.x86_64 32:9.7.3-8.P3.el6_2.2                                             
  bind-utils.x86_64 32:9.7.3-8.P3.el6_2.2                                            
  cvs.x86_64 0:1.11.23-11.el6_2.1                                                    
  dhclient.x86_64 12:4.1.1-25.P1.el6_2.1                                             

[...]

  xorg-x11-server-common.x86_64 0:1.10.4-6.el6_2.3                                   
  xulrunner.x86_64 0:10.0.3-1.0.1.el6_2                                              
  yelp.x86_64 0:2.28.1-13.el6_2                                                      
  yum.noarch 0:3.2.29-22.0.2.el6_2.2                                                 
  yum-plugin-security.noarch 0:1.1.30-10.0.1.el6                                     
  yum-utils.noarch 0:1.1.30-10.0.1.el6                                               

Complete!

At this point, your system is fully up to date. As the kernel was updated as well, a reboot is the recommended next action.

If you want to install the latest release of the Unbreakable Enterprise Kernel Release 2 as well, you need to edit the .repo file and enable the respective yum repository (e.g. "ol6_UEK_latest" for Oracle Linux 6 and "ol5_UEK_latest" for Oracle Linux 5) manually, by setting enabled to "1". The next yum update run will download and install the second release of the Unbreakable Enterprise Kernel, which will be enabled after the next reboot.

-Lenz

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Wednesday Mar 21, 2012

Want to Patch your Red Hat Linux Kernel Without Rebooting?

Patched Tube by Morten Liebach
Patched Tube by Morten Liebach (CC BY 2.0)

Are you running Red Hat Enterprise Linux? Take back your weekend and say goodbye to lengthy maintenance windows for kernel updates! With Ksplice, you can install kernel updates while the system is running. Stay secure and compliant without the hassle.

To give you a taste of one of the many features that are included in Oracle Linux Premier Support, we now offer a free 30-day Ksplice trial for RHEL systems. Give it a try and bring your Linux kernel up to date without rebooting (not even once to install it)!

For more information on this exciting technology, read Wim's OTN article on using Oracle Ksplice to update Oracle Linux systems without rebooting.

Watch Waseem Daher (one of the Ksplice founders) telling you more about Ksplice zero downtime updates in this screencast "Zero Downtime OS Updates with Ksplice"

- Lenz

Friday Mar 16, 2012

Oracle Linux Forum

This forum includes live chat so you can tell Wim, Lenz, and the gang what you really think.

Linux Forum - Tuesday March 27

Since Oracle recently made Release 2 of its Unbreakable Enterprise Kernel available (see Lenz's blog), we're following up with an online forum with Oracle's Linux executives and engineers. Topics will be:

9:30 - 9:45 am PT
Oracle's Linux Strategy

Edward Screven, Oracle's Chief Corporate Architect and Wim Coekaerts, Senior VP of Linux and Virtualization Engineering, will explain Oracle's Linux strategy, the benefits of Oracle Linux, Oracle's role in the Linux community, and the Oracle Linux roadmap.

9:45 - 10:00 am PT
Why Progressive Insurance Chose Oracle Linux

John Dome, Lead Systems Engineer at Progressive Insurance, outlines why they selected Oracle Linux with the Unbreakable Enterprise Kernel to reduce cost and increase the performance of database applications.

10:00 - 11:00 am PT
What's New in Oracle Linux

Oracle engineers walk you through new features in Oracle Linux, including zero-downtime updates with Ksplice, Btrfs and OCFS2, DTrace for Linux, Linux Containers, vSwitch and T-Mem.

11:00 am - 12:00 pm PT
Get More Value from your Linux Vendor

Why Oracle Linux delivers more value than Red Hat Enterprise Linux, including better support at lower cost, best practices for deployments, extreme performance for cloud deployments and engineered systems, and more.

Date: Tuesday, March 27, 2012
Time: 9:30 AM PT / 12:30 PM ET
Duration: 2.5 hours
Register here.

- Rick

Tuesday Mar 13, 2012

Who the Linux Developer Met on His Way to St. Ives

For some reason I still remember this nursery riddle:

"As I was going to Saint Ives
I met a man with seven wives
Each wife had seven sacks
Each cat had seven cats
Each cat had seven kits
How many were going to St Ives?

The answer, of course, is one. More about the riddle here.

Little did I know, when I first learned it, that this rhyme would help me understand the Oracle Exadata Database Machine. Miss Blankenship, please forgive me:

As I was going to St Ives
I met a man with 8 Oracle Exadata Machines
Each machine had 8 sockets
Each socket had 8 cores
Each core had 2 threads
How many CPU's were going to St Ives?

If your i-phone has hobbled you to the point that you can no longer do simple arithmetic in your head, you can get the answer to that riddle by listening to these podcasts (the first one even provides notes):

Podcast: How Oracle Linux Was Optimized for the Oracle Exadata Database Machine

Turns out that when you use off-the-shelf components to build a NUMA system like the Exadata, you lower your hardware costs, but you increase the software work that must be done to optimize the system. Oracle Linux already had a set of optimizations well suited to this task. Chris Mason, director of Linux kernel engineering at Oracle, describes the process engineering used to optimize Exadata's integrated stack, touching everything from storage, to networking, the CPU, I/O speeds, and finally the application. Great Q&A, too.

Podcast: What's So Great About Oracle's Unbreakable Enterprise Kernel?

It's easy to replace your tired rust-bucket of a Linux kernel with the chromed-out Unbreakable Enterprise Kernel from Oracle, but why would you? Sergio Leunissen, Oracle Vice President, and Lenz Grimmer, blogger extraordinaire, explain why it's worth your time to use the Unbreakable Linux Kernel. Sergio and Lenz explain why Oracle went to the trouble to engineer its own kernel, what's included in Release 2, how it is tested, how it is optimized for the Oracle stack, the close relationship with the Linux community, and what benefits it brings developers and sysadmins.

Where to Get It, How to Use It

As you may have already heard, Release 2 of Oracle's Unbreakable Enterprise Kernel for Linux is now available. Here are some resources to help you get started.

- Rick with Todd Trichler

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Wednesday Jan 25, 2012

Does Your Weekend Workload Look Like This?

We have a couple of resources to help you dive under.

Article: How Dell Migrated From SUSE Linux to Oracle Linux

In June of 2010, Dell made the decision to migrate 1,700 systems from SUSE Linux to Oracle Linux, while leaving the hardware and application layers unchanged. Suzanne Zorn worked with Jon Senger and Aik Zu Shyong, from Dell, to understand exactly how Dell did it. In this article, they describe Dell's server environment, the migration process, and what they learned. The article covers:

  • Preparation, including the use of a "scratch" area
  • Archiving configuration files
  • Conversion of MPIO to PowerPath with a custom script
  • Re-imaging the new OS and installing with kickstart
  • Restoring the configuration files
  • Adjusting profiles
  • Restarting database and applications, and verifying correct operation.

More about Oracle Linux here.

Demo: Update the Oracle Linux Kernel with Ksplice

Waseem Daher uses the command line to demonstrate how you can use Ksplice to install kernel updates to Oracle Linux without rebooting, even while your applications are still running. He also shows you how to use the Uptrack utility in Ksplice to manage your Linux packages more easily. It's only 18 minutes long, and well worth your time.

Why big wave surfers do it.

- Rick
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Tuesday Jan 03, 2012

Next OTN Sysadmin Day is on January 18

Our next OTN Sysadmin Day will be held on January 18 in Salt Lake City, Utah. As usual, we will have two tracks of hands-on-labs:

Time Session
8:00 am System Shakedown
9:00 am Oracle's Dual OS Strategy / Overview of OTN
 

Oracle Solaris Track

Oracle Linux Track

10:00 am HOL: ZFS HOL: managing packages, configuring services
11:30 am HOL: Exploring OS, network, and storage virtualization HOL on Storage Part I: managing storage and file systems
1:00 pm Lunch Break
2:00 pm HOL: Managing software with IPS HOL on Storage Part II: Device Mapper, BTRFS
3:00 pm Presentation: Oracle Enterprise Manager Ops Center 11g
4:00 pm Discussion: What are the most pressing issues for sysadmins today?
5:00 pm We all go home

Participants of previous OTN Sysadmin Days found the hands-on labs particularly valuable. You get to learn by doing. And what you get to do is install, configure, and manage the technologies of Oracle Solaris 11 and Oracle Linux in the same way as you would in the real world.

OTN Sysadmin Day in Salt Lake City is free, but you must register. Please stay for the feedback session at the end. They tend to be pretty spirited, and you might win a neat prize. Address:

Salt Lake City Marriott City Center
220 South State Street
Salt Lake City, UT 84111

If you'd like to see some pictures from the Sacramento event, go to the "OTN Sysadmin Day Sacramento" photo folder on the OTN Garage on Facebook.

To find out what there is to do is Salt Lake City and Utah, click on the ski page above. It will take you to National Geographic's Guide to Utah.

- Rick
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Friday Dec 16, 2011

Two Sysadmin Articles Make OTN's Top 20

In the OTN blog, Justin reports that two sysadmin-related articles made OTN's top 20 list for 2011:

Number 2
Taking Your First Steps with Oracle Solaris 11
- by Brian Leonard and Glenn Brunette

Number 11
How I Simplified the Installation of Oracle Database on Oracle Linux
- by Ginny Henningsen

Boo-yah!

The good work of Brian, Glenn, and Ginny makes those of us in the Systems Community of OTN particularly proud because the number of OTN readers who are system admins and developers is dwarfed by the number who are Java developers. Even making the top 20 is notable. To Brian, Glenn, and Ginny, a heartfelt:

- Rick

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Tuesday Sep 27, 2011

Linux-Related Content and Roadmap at Oracle OpenWorld

Interested in the Oracle Linux strategy and roadmap direct from Wim Coekaerts, VP of Linux Engineering at Oracle? Find out where and when, plus how other companies like Cisco and Intel are using Oracle Linux. Here's the summary of Linux-related content at Oracle OpenWorld:

Focus on Oracle Linux

The summary covers:

  • Keynotes
  • General Session
  • Oracle Linux and Oracle VM Customer Forum

- Rick
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Friday Sep 16, 2011

The Confederate Hellcat and Other Minimal Configurations

I've been looking for a reason to use this picture of the Confederate HellCat for a while, now. A souped-up Harley engine in a radical sportbike chassis. Makes you want to run into the garage and roll around in dirty oil rags, doesn't it?

Here's another minimal configuration:

Recommendations for Creating Reduced or Minimal Oracle Solaris Configurations

Some sites use OS minimization to reduce the security footprint of their Oracle Solaris installations. Others do it to reduce the administrative burden of patching and updating software. But minimization has both risks and benefits. Glenn Brunette provides his recommendations for mitigating the risks and reaping the benefits. Covers initial installation, package removal, patching, and what to watch out for. Applies to Oracle Solaris 10 and prior releases.

And since we're talking about simplification, this article might also be apropos (that's French for "I like American beer"):

How I Simplified the Installation of Oracle Database on Oracle Linux

Ginny Henningsen describes how she simplified the installation of Oracle Database 11g by automatically pre-configuring Oracle Linux with the required software packages and correct kernel parameters. Hint: using the "oracle-validated " RPM package.

- Rick
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Wednesday Sep 14, 2011

OTN Sysadmin Day - Seattle

OTN Sysadmin Day held in Sacramento on Sep 8 was the first time we presented two tracks of hands-on labs:

Time Session
8:00 am System Shakedown
9:00 am Oracle's Dual OS Strategy / Overview of OTN
 

Oracle Solaris Track

Oracle Linux Track

10:00 am HOL: ZFS HOL: managing packages, configuring services
11:30 am HOL: Exploring OS, network, and storage virtualization HOL on Storage Part I: managing storage and file systems
1:00 pm Lunch Break
2:00 pm HOL: Managing software with IPS HOL on Storage Part II: Device Mapper, BTRFS
3:00 pm Presentation: Oracle Enterprise Manager Ops Center 11g
4:00 pm Discussion: What are the most pressing issues for sysadmins today?
5:00 pm We all go home

Participants found the hands-on labs particularly valuable. You get to learn by doing. And what you get to do is install, configure, and manage the technologies of Oracle Solaris 11 and Oracle Linux in the same way as you would in the real world.

Next Sysadmin Day

We are doing another one in Seattle, on September 22nd. From 8:00 am to 5:00 pm. It's free, but you must register. Please stay for the feedback session at the end. They tend to be pretty spirited, and you might win a neat prize. I'll tell you more if you make it to Seattle.

Our next Sysadmin Day won't happen till January 18 (Salt Lake City), so do what you can to make it to Seattle. It's being held at the Seattle Westin Hotel, 1900 5th Avenue.

If you'd like to see some pictures from the Sacramento event, go to the "OTN Sysadmin Day Sacramento" photo folder on the OTN Garage on Facebook.

- Rick
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Monday Sep 05, 2011

Recommened Linux sysadmin/developer reading: the Ksplice blog

In July, Oracle acquired Ksplice, a small company based in Cambridge, MA. If you haven't heard about Ksplice yet, it's some very cool technology that enables you to patch a running Linux kernel without rebooting. Ksplice support is now included in our Premier Linux Support offerings. Check this Getting Started with Oracle Ksplice page for details.

The Ksplice Blog which used to live on the Ksplice home page has now been migrated to the Oracle Blogs. It's a treasure-trove of useful information for Linux system administrators and developers, make sure to subscribe to it!

Here are some recent entries and there's more to come!

Wednesday Aug 31, 2011

Save disk space on Linux by cloning files on Btrfs and OCFS2

Rebecca W: Dolly
"Dolly" by Rebecca W (CC BY-SA 2.0).

Btrfs and OCFS2 are two very advanced file systems for Linux. Btrfs is a next-generation local file system for Linux, and it provides a number of nice features like snapshots and subvolumes, dynamic resizing and built-in RAID functionality. OCFS2 is the ideal candidate for creating cluster file systems that can be shared across multiple machines (but it can also be used for local storage).

There is one neat little feature that both Btrfs and OCFS2 have in common — they are capable of creating "lightweight" copies ("snapshots" or "clones") of a file.

In this case the file system does not create a new link pointing to an existing inode, it rather creates a new inode that shares the same disk blocks as the original file. This means that this operation only works within the boundaries of the same file system or subvolume. The outcome looks very much like a copy of the source file, but the actual data blocks have not been duplicated. Due to the copy-on-write nature, a modification of any one of the files will not be visible in the other file. Note that this should not be confused with hard links – this web page provides a good explanation of the differences.

For Btrfs, you can invoke this feature by using the cp(1) utility with the --reflink option, which was added to the GNU coreutils in version 7.5 (released in Aug. 2009):

cp --reflink <source file> <destination file>

Adding support for the reflink implementation of OCFS2 to cp still seems to be under development. For now, you need to download and install a separate reflink binary from here. It works like the ln(1) utility:

reflink <source file> <destination file>

Wim covered OCFS2 reflink in more detail in a blog post a while ago and there is another example for OCFS2 on our Wiki.

These kind of file clones save disk space and allow copy operations to perform much quicker than actually copying entire files. This can be quite useful if you need to create copies of very large files that differ very little from each other, e.g. virtual machine disk images. In this case the disk space savings can be quite significant!

Thursday Aug 25, 2011

Next OTN Sysadmin Day is in Sacramento

Bottom Line: next OTN Sysadmin Day is September 8 in Sacramento.
Free, but registration is required.

One of the most subtle yet powerful skills I learned from The Missus is how to tell the difference between what was better and what I preferred.

Motorcycle magazines, for instance, spend an awful lot of time telling us why one motorcycle is better than another. They do this by employing their best interpretation of objective criteria: acceleration, braking, cornering, carrying capacity, conveniences, ergonomics, and sometimes even the personal riding experience of the reviewer.

There's nothing wrong with that. Very useful stuff. And fascinating to read. Except that it gets me all confused. Or confuzzled, as my daughter calls it. The objective criteria makes me think one bike is better than the other. But when I buy it, why am I less than fulfilled?

Because features and capabilities don't often match personal preference.

Although we don't usually put personal preference at the top of the list when choosing an operating system, we shouldn't ignore it. Personal preference is not just whim. It takes into account the job we're trying to accomplish, the way we have to handle it, and the tools we prefer to use. In fact, ignoring our personal preference has an impact on productivity: if we hate "our ride," we're not going to get very good at using it, are we?

OTN's second Sysadmin Day (read about the first) will begin with an overview of Oracle's dual OS strategy. Then we'll split off into two tracks, one with hands-on labs for Oracle Linux, one for Oracle Solaris.

Time Session
8:00 am System Shakedown
9:00 am Oracle's Dual OS Strategy
 

Oracle Solaris Track

Oracle Linux Track

9:30 am Overview of Oracle Solaris Overview of Oracle Linux
10:00 am HOL: ZFS HOL: managing packages, configuring services
11:30 am HOL: Exploring OS, network, and storage virtualization HOL on Storage Part I: managing storage and file systems
1:00 pm Lunch Break
2:00 pm HOL: Managing software with IPS HOL on Storage Part II: Device Mapper, BTRFS
3:00 pm Presentation: Oracle Enterprise Manager Ops Center 11g
4:00 pm Discussion: What are the most pressing issues for sysadmins today?
5:00 pm We all go home

Consider it an Oracle Demo Day, if you will. It's free, but you must register to attend.

As for me, after spending a couple of years riding the canyons on a 2005 Ducati 800SS, a 2003 Ducati ST4 with a 4-valve 996 engine, Ohlins shocks, and Marchesini wheels, a 2005 BMW K1200S, and the bikes of a few friends, I went back to a 2006 Harley Davidson Fat Boy. Even though the other bikes performed much better, I prefer the Fat Boy. And my wicked smaht Missus.

- Rick
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Thursday Aug 18, 2011

The Impact of Oracle Optimized Solutions on a Sysadmin's Job

When Oracle acquired Sun we kept it simple. In doing so we came up with Oracle Optimized Solutions. Of course they're great for business because they are assembled from a pre-configured stack of Oracle products that we test and use ourselves, but are they be great for Sysadmins? I decided to ask.

The best person to ask anything about Oracle Optimized Solutions is Marshall Choy. Not only is Marshal the director of the engineering group that selects and assembles these systems, but he began his high tech career as a sysadmin working on both Solaris and Linux systems. Marshall agreed to let us put him on the spot, so Justin interviewed him on OTN TechCast. In addition to talking about a sysadmin's job, Marshall explains the patching strategy for these types of stacks. Here are some of the questions we asked him.

  1. What's the difference between Oracle Optimized Solutions and Oracle Engineered Systems?
  2. What will this mean my job as a sysadmin - will my skills become obsolete? Will I be replaced by someone less skilled?
  3. I'm not sure I want to outsource my sysadmin skills to Oracle - how will these optimized solutions change what I spend my time doing?
  4. Aren't we just turning back the clock 20 years - why did you decide to build a proprietary vertical stack?
  5. What if I want to change something in the stack, how will it affect my support contract?
  6. How often do you update the components in the stack, and do I get those updates for free?
  7. How do I install updates and patches?

It's a good show. It lasts 14 minutes. Don't miss it.

- Rick
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Wednesday Aug 10, 2011

Join OTN Or ...

...The Lemur Gets It!


Turns out Oracle wants more sysadmins (Linux, Solaris, systems, storage, or network) to become official, bonafide, full-blown OTN members. I explained that sysadmins aren't really the "joining" type, but I lost. Oracle wants more sysadmins to join OTN. Period.

So I've been wondering how I could convince the more reluctant among you to become official, bonafide, full-blown OTN members. After all you, your bookie, and your bookie's mother-in-law can read our technical articles, view our OTN videos (may take time to load), and visit just about every part of the OTN Systems website without signing up for anything.

But there is a bunch of very cool stuff you can't do unless you're a member. This month I'll tell you about one.


Download Software For Free

You can't download our software for free unless you're an OTN member.

I know Oracle's license terms are not the same as Sun's were, but you still get to download and horse around with world-class software for free. If you're anywhere within a decade of your mid-life crisis, you'll clearly remember when you had to actually pay a lot of money for good software. All we ask is that you be honest about when you deploy our software. That's only fair.

For all the details, read the OTN developer license.

You can read about other benefits of membership here.

So, if you really want that lemur to have a future, sign up here, check the "Oracle Technology Network" box under "My Community Memberships," and identify yourself as a sysadmin.

And while you're at it, sign up for our newsletter. It'll highlight the best content we've published over the previous month, in case you weren't paying attention.

- Rick
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Wednesday Jun 15, 2011

Pimp my Ride - Installing Additional Packages on Oracle Linux

Lee Cannon: Wings Wheels 2010
"Wings Wheels 2010" by Lee Cannon (CC BY-SA 2.0).

Oracle Linux already ships with an impressive amount of software packages which can be downloaded from our public Yum server.

For example, adding the external package repository for Oracle Linux 6.1 is a trivial task:

  1. Download and copy the appropriate yum configuration file in place, by running the following command as root:
    # wget -O /etc/yum.repos.d/public-yum-ol6.repo \
      http://public-yum.oracle.com/public-yum-ol6.repo
  2. Now edit the file using your favorite text editor and enable the appropriate repository ([ol6_u1_base] in our case) by changing the value of the enabled variable from 0 to 1.
  3. Now you can run yum list all to get a full list of all available packages. You can install them by running yum install <packagename>
However, being a distribution with a focus on the enterprise and data center, the package selection is limited to this scope. If you are looking for additional packages, you would have to either compile them from source or download pre-built binaries from an external package repository.

Enter EPEL, the "Extra Packages for Enterprise Linux" repository. According to their extensive FAQ, EPEL "is a volunteer-based community effort from the Fedora project to create a repository of high-quality add-on packages that complement the Fedora-based Red Hat Enterprise Linux (RHEL) and its compatible spinoffs, such as CentOS and Scientific Linux.".

Oracle Linux is based on RHEL, too, and is 100% userland-compatible with it. Therefore any package available from EPEL will install and run just fine, giving you access to a large pool of additional software. However, please keep in mind that this software is not covered by any Oracle Linux Support agreement you may have!

You can add and enable the EPEL repository by performing the following steps (as the root user):

  1. Download and install the repository package which includes the appropriate repository information for your version of Oracle Linux:
    rpm -Uvh http://download.fedora.redhat.com/pub/epel/6/x86_64/epel-release-6-5.noarch.rpm
  2. The repository is automatically enabled, which you can verify by running yum repolist.
  3. To get a listing of all the additional packages you now have access to, run yum list available | grep epel | less.
  4. Now simply run yum install <packagename> to install any of the additional packages (over 4800 for Oracle Linux 6, last time I counted!).
Enjoy!

See more articles about Oracle Linux at the Oracle Linux Blog!

Monday Jun 06, 2011

Feed Me!

Photo courtesy of William Lee.

At the bottom of every Oracle's web page there's a corporate RSS Feed button. It takes you to a page that has some useful high-level feeds. But, unlike high-level corporate planners, we are privy to the fact that Systems admins and developers constitute a higher life form. So we created a set of highly refined feeds just for you.

The OTN System Admin and Developer Community Feeds are grouped into these categories:

By Technology

  • Oracle Enterprise Manager Ops Center 11g
  • Solaris Studio
  • Oracle Linux
  • Solaris 11 Express
  • Storage
  • Servers
  • Desktops
  • Peripherals

By Topic

  • Availability
  • Backup and Restore
  • Containers and Zones
  • Filesystems
  • Installation
  • Interoperability
  • Networking
  • Performance
  • Security
  • Tools

By Type

  • Blogs
  • Videos
  • Technical Articles

All OTN Systems Content

  • All Developer
  • All Sysadmin
  • All
  • Let me know if you'd like any more.

    - Rick System Admin and Developer Community of OTN

    Tuesday Mar 15, 2011

    Long Title, Quick Start!

    Linux RAC ClusterClustered applications are the keystone to highly available environments. Where you have clustering, you usually have databases – and where you have clustered databases, it is hard to avoid Oracle Real Application Clusters (Oracle RAC).

    Clustered databases aren't generally known for ease of setup. The Sun BluePrints Program was orginally created over ten years ago to focus on this topic specifically and numerous books and white papers were a mainstay. We once tried to write a book on this topic in six months and this was so complicated that it couldn't be done. However, technology has progressed and it is now much easier to create powerful solutions without all the pain-and-suffering.

    As witnessed by Sridhar Ranganathan's and Jeffrey Wright's latest opus: Oracle9i Real Application Clusters Database Quick Start Install Guide for Sun ZFS Storage Appliance Using Oracle Linux. When we say "Quick Start," we mean it: long title, quick start! In the fewest pages possible they take you through everything you need, from downloading and installing the software, to setting up the disk, and creating the database itself.

    No reason to shy away from clustering any longer.

    - Kemer

    Monday Jan 24, 2011

    When You Can't Find the Torque Wrench

    I come from a part of the world that considers doing it yourself without the right tools a great sign of resourcefulness (Lima, Peru.) I live in part of the world that considers doing it yourself with the right tools a sign of preparedness (Colorado, USA).

    Both may be true, but sometimes the torque wrench refuses to reveal its location and that usually happens when the VP of IT has chewed out the Director of IT who has called your boss and his best buddies into the corner office for a serious discussion whose resulting action items are going to land on your head just as you're heading out to the local sysadmin bar.

    That's when you want to have a couple of quick meals in your pantry:

    Oracle Linux Validated Solutions

    Pre-tested, validated architectures—including software, hardware, storage, and network components—plus documented best practices. Improved performance, scalability, and reliability of Linux solutions, with faster, lower-cost implementations for dozens of leading applications.

    Oracle Sun Hardware Solutions

    Slightly different from the Linux Validated Configurations, above, but similar in spirit, Oracle's Sun Hardware Solutions assemble the stack components that are best suited to optimize the performance and management of these seven popular enterprise business applications.

    You can always find these links under the Product Pages and Resource Pages headings in the right-most column of OTN's Sysadmin and Developer Community.

    - Rick

    Wednesday Dec 15, 2010

    What Day Is It And Why Am I Wearing a Little Furry Skirt?

    This morning I woke up singing Bohemian Rhapsody. A hostile dude wearing a little furry skirt and a biker lid with a broken bull horn was glaring at me from the bathroom mirror. He had a battle axe. My dogs were both staring up at me, demanding in the way that dogs do, to guess what they were thinking. The shower, which somebody had turned on, was in a grimy Belarus apartment and the beer-belied landlord, in a threadbare ribbed tank-top that had once been white, was insisting that I pay my back rent. Now. I glanced at my wife. She was asking me what I wanted to buy our daughter for her birthday. Then at my empty bowl of oatmeal with a spoon sticking out of it. Had I eaten breakfast already?


    I hate jet lag.

    You might have better luck figuring out what's going on, at least about Oracle VM Templates, if you watch this video of Wim Coekaerts. (Does that sound Swedish to you?) It's a replay of an OTN Live show in which Wim Coekaerts (it sounds Swedish to me!) explains to Justin how VM Templates make deploying an application stack onto a new virtualized server a lot simpler than the old process of rowing across the ocean and doing you-know-what to the beleaguered virtual server. (Weren't the vikings from Sweden?)

    Don't let Wim's rather innocent appearance fool you. His ancestors were probably Budweiser swilling-Viking dudes like the one in my mirror. So when he shifts gears and starts talking about Oracle's Unbreakable Linux Kernel, he's probably gonna mention battering rams and catapults, and maybe even the coolest medieval weapon of all, the trebuchet. The Vikings did their damage before the Middle Ages, though, didn't they?

    Oh well, Justin is sporting a slick new sweater so the show, trebuchet or no trebuchet, is definitely worth your while.

    Here's a couple more OTN Live shows that might also interest you:

    I'm going to pour myself another bowl of oatmeal and try to find the stairs.

    - Rick

    Friday Oct 08, 2010

    Sysadmin Resources for Oracle Linux

















    Ducati missed a great opportunity to call the latest upgrade to my favorite sportbike the Ducati 848 Linux Edition. I think Larry needs to make a phone call....

    To make up for Ducati's unpardonable slight to the entire Linux community, we've highlighted some Linux technical content on the front page of the OTN Systems Community, but front page headlines have a tendency to change quickly.

    So here's a quick summary that you can slide into the map sleeve of your tank bag (or your Stich jacket if you prize function over form):

    What's New

    This page will let you know about Oracle announcements, new resources, community blogs or comments, and anything else related to Oracle Linux. Bookmark it someplace safe.

    Downloads

    Get the new unbreakable kernel from Oracle's Public Yum Server or go to the Oracle Linux download center to select from a variety of Linux-related software.

    Documentation

  • Install Guides for Oracle Software on Oracle Linux
  • Oracle Linux 4 Release Notes
  • Oracle Linux 5 Release Notes
  • Red Hat Enterprise Linux Documentation
  • Also click on the Reference link in the left nav bar of the Linux-Solaris CommandComparo for general linux reference material for sysadmins
  • Forums, Blogs, and Other

    Training and Certification

    Oracle University offers Linux sysadmin certification based on Enterprise Linux that closely maps to Oracle's Linux training offerings. To become certified, you must demonstrate a high level of proficiency with Enterprise Linux including system administration, networking, and security.

    Oracle Unbreakable Linux Network

    The Unbreakable Linux Network is a community that provides Linux software patches, updates, and fixes, plus information on up2date program and support policies. Only for Linux users with Oracle support subscriptions.

    Linux-Solaris Command Comparo

    This wiki shows the equivalent command syntax for common administrative tasks in Oracle Solaris 10 and Oracle Enterprise Linux 5 – especially tasks that have tricky syntax or that you frequently need to double-check. Add, complete, and modify entries to make the wiki more useful and accurate. Anyone can read it, but to make changes, first register and then log in.

    Other Oracle Linux Resources

    Here's Oracle's announcement about the Oracle Unbreakable Linux Kernel, in case you missed it.

    More reviews about the Ducati 848 Linux Edition here:

    - Rick

    Monday Aug 30, 2010

    The Fat Bloke Sings About VirtualBox

    One of my favorite bike builders is Russell Mitchell, owner of Exile Cycles. He designed and his crew builds bikes like the Fat Bloke pictured above. You can buy the bike already built like the movie stars do, or initiate yourself into the world of old-school motorcycling by building it yourself from parts in Russell's shop.

    Here's another Fat Bloke that's got something interesting to offer. Migrating from VMWare to VirtualBox with Oracle Enterprise Linux describes how to move a virtual machine from one virtualization platform to another. Kinda like moving your hard drive from one machine to another, as the Fat Bloke puts it. Or swapping out the engine on Exile's Brown Pearl and dropping it into the Hot Rod. Or, God-forbid, a Honda Gold Wing.

    The writeup by Fat Bloke the blogger includes these topics:

  • Preparing to Migrate
  • Exporting the Virtual Machine
  • Importing into VirtualBox
  • Installing the VirtualBox Guest Additions
  • An Alternative Approach for Advanced Users
  • My favorite of Russell's bikes is the Silver Bullet, though the Brown Pearl is a close second.

    - Rick
    About

    Contributors:
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    Kemer Thomson
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