Sunday Oct 05, 2014

How to setup passwordless ssh in Exadata using dcli

 




Setting passwordless ssh root connection using dcli is fast and simple and will easy later to execute commands on all servers using this utility.


In order to do that you should have either:


DNS resolution to all Database and Storage nodes OR have them registered in /etc/hosts


1) Create a parameter file that contains all the server names you want to reach via dcli, tipically we have a cell_group for storage cells, a dbs_group for database servers and an all_group for both of them.


The parameter files will have only the server name, in short format


ie: all_group will have on an Exadata quarter rack:


dbnode1
dbnode2
cell1
cell2
cell3


2) As root user create ssh equivalence:


ssh-keygen   -t    rsa


3) Distribute the key to all servers


dcli -g ./all_group -l root -k -s '-o StrictHostKeyChecking=no'


4) check 


dcli -g all_group -l root hostname 



 

Bash security fix made available for Exadata

Complete information about the security fix availability should be reviewed, before applying the fix, in MOS DOC:


 Responses to common Exadata security scan findings (Doc ID 1405320.1)


The security fix is available for download from:


http://public-yum.oracle.com/repo/OracleLinux/OL5/latest/x86_64/getPackage/bash-3.2-33.el5_11.4.x86_64.rpm


The summary installation instructions are as follows:


1) Download getPackage/bash-3.2-33.el5_11.4.x86_64.rpm


2) Copy bash-3.2-33.el5_11.4.x86_64.rpm into /tmp at both database and storage nodes.


3) Remove rpm  exadata-sun-computenode-exact



rpm -e exadata-sun-computenode-exact



4) On compute nodes install bash-3.2-33.el5_11.4.x86_64.rpm using this command:



 rpm -Uvh /tmp/bash-3.2-33.el5_11.4.x86_64.rpm



5) On storage nodes  install bash-3.2-33.el5_11.4.x86_64.rpm using this command:




rpm -Uvh --nodeps /tmp/bash-3.2-33.el5_11.4.x86_64.rpm


6) Remove /tmp/bash-3.2-33.el5_11.4.x86_64.rpm from all nodes


As a side effect of applyin this fix,  during future upgrades on the database nodes, a warning will appear informing:



The "exact package" was not found and it will use minimal instead.


That's a normal and expected message and will not interfere with the upgrade. 







Wednesday Oct 17, 2012

Exadata Parameter _AUTO_MANAGE_EXADATA_DISKS

Exadata auto disk management is controlled by the parameter _AUTO_MANAGE_EXADATA_DISKS.

The default value for this parameter is TRUE.

When _AUTO_MANAGE_EXADATA_DISKS is enabled, Exadata automate the following disk operations:

If a griddisk becomes unavailable/available, ASM will OFFLINE/ONLINE it.
If a physicaldisk fails or its status change to predictive failure, for all griddisks built on it ASM will DROP FORCE the failed ones and DROP the ones with predictive failures.
If a flashdisk performance degrades, if there are griddisks built on it, they will be DROPPED FORCE in ASM.
If a physicaldisk is replaced, the celldisk and griddisks will be recreated and the griddisks will be automatically ADDED in ASM, if they were automatically dropped by ASM. If you manually drop the disks, that will not happen.
If a NORMAL, ONLINE griddisk is manually dropped, FORCE option should not be used, otherwise the disk will be automatically added back in ASM.
If a gridisk is inactivated, ASM will automatically OFFLINE it.
If a gridisk is activated, ASM will automatically ONLINED it.

There are some error conditions that may require to temporarily disable _AUTO_MANAGE_EXADATA_DISKS.

Details on MOS 1408865.1 - Exadata Auto Disk Management Add disk failing and ASM Rebalance interrupted with error ORA-15074.

Immediately after taking care of the problem _AUTO_MANAGE_EXADATA_DISKS should be set back to its default value of TRUE.

Full details on Auto disk management feature in Exadata (Doc ID 1484274.1)

Thursday Sep 27, 2012

Oracle Engineered Systems, Amazing Exalogic

Sometimes I have heard that Exalogic is just a bunch of servers connected using infiniband, something that you can easily build yourself at a lower cost.


That comments misses completely 2 things:


1) What is the idea behind an Oracle engineered system, and the back that Oracle provides for them 


2) What is Exalogic


This amazing 5 minute presentation explains Exalogic potential:


Oracle Exalogic Elastic Cloud



Monday Jul 25, 2011

Configuring FTP on Exadata

Exadata is installed with the minimum set of rpm's required to make it work as a database server.
In many cases you will need to install by yourself the rpms required to make available some specific functions, like FTP.

Exadata is installed either with Oracle Enterprise Linux or Solaris Express. This instructions match the Linux distribution, and can be used on any RH compatible Linux, not only OEL on Exadata.

You can find the rpm's on the Oracle Enterprise Linux Distribution Disk, downloadable from edelivery.oracle.com

Install the Following rpms:

[root@exand02 rpms]# ls
ftp-0.17-35.el5.x86_64.rpm pam-rpms
vsftpd-2.0.5-16.el5_4.1.x86_64.rpm
lftp-3.7.11-4.el5.x86_64.rpm tftp-server-0.49-2.0.1.x86_64.rpm

The Command to Install

[root@exand02 rpms]# rpm -Uivh vsftpd-2.0.5-16.el5_4.1.x86_64.rpm ftp-0.17-35.el5.x86_64.rpm lftp-3.7.11-4.el5.x86_64.rpm

Start Service vsftpd

[root@exand02 rpms]# service vsftpd start
Starting vsftpd for vsftpd: [ OK ]
[root@exand02 rpms]# service vsftpd status
vsftpd (pid 9274) is running...

Configure Automatic vsftp Start

[root@exand02 rpms]# chkconfig vsftpd on

[root@exand02 rpms]# chkconfig --list | grep vsftpd
vsftpd 0:off 1:off 2:on 3:on 4:on 5:on 6:off

echo "service vsftpd status" >> /etc/rc.local

[root@exand02 rpms]# tail -2 /etc/rc.local
########### END DO NOT REMOVE Added by Oracle Exadata ###########
service vsftpd start

Edit /etc/vsftpd.conf

Set the following parameters on vsftpd.conf

#anonymous_enable=YES (changed to NO to allow Exadata users to ftp)
anonymous_enable=NO

#userlist_enable=YES (changed to NO to allow Exadata users to ftp)
userlist_enable=NO

Test

[root@exand02 vsftpd]# ftp exand02

Connected to exand02 (10.25.104.130).
220 (vsFTPd 2.0.5)
Name (exand02:root): oracle
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.

ftp> pwd
257 "/home/oracle"

ftp> ls
227 Entering Passive Mode (10,25,104,130,85,192)
150 Here comes the directory listing.
drwxr-xr-x 3 1001 500 4096 May 20 19:47 local
drwxr----- 3 1001 500 4096 May 03 12:20 oradiag_oracle
-rw-r--r-- 1 1001 500 1020 Jun 01 14:41 ~oraclec
226 Directory send OK.

ftp> bye
221 Goodbye.

Sunday May 08, 2011

RAC, ASM and Linux Forum, May 18, 2011: EXADATA Production Customers updates

Consolidation, scale up and backup of VLDB's on Exadata, Customer presentations[Read More]
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