Sunday Nov 22, 2009

My Home Media Server using OpenSolaris, ZFS, and free software

A while ago, I wrote several blog entries about what I did to set up a media server at home.  I'm writing this blog entry to wrap things up with some details about how much it all cost, and the software I'm running on the computer now.


I decided to design a "media server" for home that would be the main data storage for our family's music, photos, recorded TV shows and movies, and personal documents and backups of our home directories on the computers we commonly use at home.  I had a few objectives for the media server:
  1. All of this data would be in a single computer that we could grab and stick in the car in case of emergency.  Friends of ours lost their house, but they had the foresight of having all of their personal data (over a terabytes' worth) on a single file server, so when they evacuated the house, they didn't lose any personal data.  Seemed like a great idea to me.
  2. The media server would store data reliably; i.e., I assumed that a disk would fail, and I wanted the media server to be able to continue working in case of failure.
  3. Reduce noise in the house as much as possible.  That meant putting the server in the garage where it could make as much fan noise as it needed to, but we wouldn't hear a thing in the home office or where we watch TV.
  4. Keep the cost down to a reasonable amount.  This was not the primary factor, but it was important enough for me to pay attention to when shopping for the components.

What I Purchased

Here's the build of materials for the computer I put together (I'm sure prices on these will have gone down since I bought them in October 2008).  Total price of the system: $742.  If you take out the cost of the disks, the rest of the computer cost $345.
  • Motherboard (, $62.99) : ECS Elitegroup A780VM-M2 Micro ATX AMD Motherboard.  Supported the cheap AMD processor I wanted, and had plenty of on-board SATA ports (6).  Remember, I want all the disk to be in a single enclosure for easy, snatch-and-grab transportation.
  • Memory (, $69.99): GSkill 4GB (2 x 2GB) DDR2 SDRAM (PC2 6400).  No reason to get greedy, and it keeps power draw and price down for the system.
  • CPU (, $59.50): AMD Athlon 64 X2 5000 Brisbane 2.6GHz Socket AM2 65W Dual-Core Processor.  Nice price for a processor that does everything I need in a media server that can also run some apps.  More on the apps in a bit.
  • Disks (, $396.80): 2 Seagate Barracuda 1.5TB 7200 RPM SATA internal disks.  Prices have gone down considerably for the storage, but this was a fair enough price last year.
  • Case (Fry's Electronics, $130): Antec Sonata III Mid Tower ATX Case.  Got good reviews, came with a 500W power supply which is plenty for what I was putting in it, and has plenty of ports and internal drive bays for the storage.

How I Set Up The Media Server

Here is the first blog entry I wrote that describes my thought process about using ZFS on OpenSolaris to store our home's data.

Here is the second blog entry I wrote, giving all the details about what I needed to do to format the disks and set up the ZFS pools and filesystems.  This was based on the OpenSolaris 2008.11 release; I plan to upgrade to a more recent release (probably an OpenSolaris build after the June 2009 release; I'd love to try the new ZFS deduplication feature).  Everything has been running fine, with the exception of the TimeSlider feature for doing automated ZFS snapshots.  That was fixed in the June 2009 release.

What I'm Running On The Media Server

The media server is doing a few things for us at home; here are the services it's providing:
  • iTunes music storage.  We have a Mac mini that we use for iTunes; all of our music is in iTunes, and the Mac mini NFS-mounts a filesystem from the media server.  I tried both CIFS (Samba) and NFS.  I preferred NFS, but it seemed to have troubles with the Mac as an NFS client.  After reading James Gosling's blog entry on what he observed with Macs and Solaris and NFS, I made a tweak on the Mac mini and everything has been working smoothly ever since.  We make this library shareable to our other Macs on the home network.
  • iPhoto storage.  The same Mac mini also stores all of our photos.
  • TiVo media backup and playback.  There is a great open source Java application called Galleon that uses the TiVo Home Media Engine (HME) API; the API lets you write your own Java apps that show up as part of the TiVo's on-screen menu system, and it lets you talk to the TiVo to grab shows off the TiVo's disk and put shows on there, among other functions.  Primarily, we use it as a way to keep backups of shows that we don't want to lose in case the TiVo's disk crashes and loses data.  This has happened several times, mostly due to unforeseen loss of power.
  • Personal finances (via Intuit's Quicken software).  To do this, I run the free, open source VirtualBox software.  I used to use VMware, but VMware isn't free and it doesn't run on any version of Solaris.  VirtualBox runs on every operating system I use, it's free, and it's improving much faster than VMware is.  So, I run Windows XP as a guest OS inside VirtualBox, and use that guest OS to run Quicken.  When I'm feeling like the guest OS is getting slow or am worried that it's collected viruses, I just blow away that guest image and go back to an earlier snapshot.

My Wish List

Are any of you doing something similar with your home setups?  If so, maybe you have done some of the things I'd like to set up but haven't gotten done yet.  Here's my wish list of apps and features I'd like to add, and I'd like to do it all natively in OpenSolaris (in other words, none of these services would need to run in a guest OS like Windows or Linux under VirtualBox):
  • DLNA server running natively in OpenSolaris.  DLNA will give me the ability to share and stream my media (photos, music, video) to the PlayStation 3.  I've played with several solutions; more on this in a moment.
  • Live streaming of TiVo content from the media server back through the TiVo.  Galleon lets me transfer shows to and from the TiVo, but not play them live.  This is a feature that the ReplayTV product had (I still miss that product, and am sorry they went out of business), and their Java app was superior in several ways to Galleon.  But, it looks like somebody has written software to let you play TiVo shows from your media server straight through the TiVo.  I just haven't gotten it running on the media server yet.

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Tuesday Dec 23, 2008

My Home Media Server on OpenSolaris + ZFS: Part 2

In my previous blog entry, I decided how ZFS will protect my data for a home media server I'm building.  Next: partition the disks on my two larger drives and install OpenSolaris on them.

This would be stupendously easy if my four disk drives were all the same size: I would type "zpool create mediapool raidz <disk1> <disk2> <disk3> <disk4>" and ZFS would give me a ton of storage all nice and protected for me.  But I have two 1TB drives and two 1.5TB drives.   My problem: ZFS wants all the pieces of a "vdev" (a virtual device; in this case, I'm creating a virtual RAID-Z device with four disks in it) to be the same size.  So I have some partitioning work to do.  I'm documenting what I did in case any of you want to use ZFS with different sized drives.

Here is my plan:
  • make sure the 1.5TB drives are the 1st and 2nd drives seen by the computer's BIOS, so that I can install OpenSolaris on one of these bigger drives
  • partition each 1.5TB drive into a 1TB partition and a .5TB partition (I recommend doing the partitioning from the Live CD instead of after installing the OS; it went easier for me this way)
  • install OpenSolaris onto the first 1.5TB drive's .5TB partition; installation will create a ZFS pool called "rpool"
  • put the four 1TB partitions into a ZFS raidz pool I will call "mediapool", my primary storage for our home's stuff
  • attach the remaining .5TB partition (from the second 1.5TB drive) to "rpool", making it a ZFS mirror pool so that the OS is protected against a single disk failure
I suppose I could've just made a single pool for storage, but I still like the idea of being able to separate my media storage from my OS.  Anyway, this is my plan for now.

Recalling that ZFS wants all the devices in a vdev to be the same size, I need to do some disk math to make sure the partition sizes are the same number of bytes.  Here's why (and don't laugh if this is all trivial to you; I'm a manager, okay?  If I don't see headcount or budget somewhere in this, I just get confused):

First of all, fdisk lets me specify partition sizes by either a percentage of the disk or a number of cylinders.  Specifying a percentage doesn't let me get precise enough to match the partition sizes on the the 1.5TB disks and the 1TB disks, so I need to specify partition size in terms of cylinders.  But cylinders aren't the same size on the two different disks.

The fdisk utility reports the following information about the 1.5TB and 1TB disks:

1.5TB Disk geometry:
Total disk size is 60800 cyls
Cylinder size is 48195 512-byte blocks
1TB Disk geometry:
Total disk size is 60800 cyls
Cylinder size is 32130 512-byte blocks

Notice that one cylinder on the 1.5TB drive is 1.5 the size (or 3/2, this way of reckoning comes in handy later) of a cylinder on the 1TB drive (48195 = 3/2 \* 32130).

I want to use as much of the 1TB drive as possible (60800 cylinders) but I can't: 60800 cylinders on the 1TB drive corresponds to 40533.33333 cylinders on the 1.5TB drive; I can't enter a non-integer number into fdisk.  I must find a size that works for both disks.  It needs to be a multiple of 3 cylinders on the 1TB drive (which would be a multiple of 2 cylinders on the 1.5TB drive).  I'll waste a little space (2 cylinders' worth on the 1TB drive or about 32MB), but that's okay given that I'll get RAID-Z error correction in return.

I'll create 1 partition on the 1TB disk, 60798 cylinders (next closest multiple of 3) == 1,953,439,740 blocks.
I'll create two partitions the 1.5TB disk:
  1. 40532 cyls == 1,953,439,740 blocks
  2. 20268 cyls (use this for the OS "rpool")
Now that I know exactly how big each partition needs to be on the four disks, I can use this easy-to-follow example to create the Solaris fdisk partitions.  It's easy; it takes less than five minutes, once I've worked out the math I just laid out here.

Next, it's time to install the OS.  I'm already running OpenSolaris from the Live CD, so I just click on the icon to install and less then 20 minutes later, it's there.

Next: create the media storage pool, using all four disks in a RAID-Z configuration:
drapeau@blackfoot:$ pfexec formatSearching for disks...done

 0. c1t0d0  /pci@0,0/pci108e,534a@7/disk@0,0
 1. c1t1d0  /pci@0,0/pci108e,534a@7/disk@1,0 
 2. c2t0d0  /pci@0,0/pci108e,534a@8/disk@0,0
 3. c2t1d0  /pci@0,0/pci108e,534a@8/disk@1,0
Specify disk (enter its number): \^C

drapeau@blackfoot:$ zpool listNAME SIZE USED AVAIL CAP HEALTH ALTROOT
rpool 444G 13.7G 430G 3% ONLINE -

drapeau@blackfoot:$ pfexec zpool create mediapool raidz c2t1d0p1 c2t0d0p1 c1t1d0p2 c1t0d0p2

Note that I used partition names for these disks, which is important: according to this helpful document, in Solaris disk device names, you'll see four primary partitions (p1-p4) and a "p0" as well which means "the whole disk".  I had to be clear to tell ZFS that I didn't want to use the whole 1TB disks, only the 1st partition on them (c2t1d0p1, c2t0d0p1).  And I told ZFS to use the 2nd partitions on the 1.5TB disks (c1t1d0p2, c1t0d0p2), which are the roughly-1TB partitions.

So, did it work?  Let's see:
drapeau@blackfoot:$ zpool list

mediapool 3.62T 132K 3.62T 0% ONLINE -
rpool 444G 13.7G 430G 3% ONLINE -

So far, so good: two ZFS pools. Let's check status:
drapeau@blackfoot:$ zpool status
 pool: mediapool
state: ONLINE
scrub: none requested

 mediapool ONLINE 0 0 0
 raidz1 ONLINE 0 0 0
 c2t1d0p1 ONLINE 0 0 0
 c2t0d0p1 ONLINE 0 0 0
 c1t1d0p2 ONLINE 0 0 0
 c1t0d0p2 ONLINE 0 0 0

errors: No known data errors

 pool: rpool
state: ONLINE
scrub: none requested

 rpool ONLINE 0 0 0
 c1t0d0s0 ONLINE 0 0 0

errors: No known data errors

drapeau@blackfoot:$ zfs list

mediapool 92.0K 2.67T 26.9K /mediapool
rpool 21.7G 415G 72K /rpool
rpool/ROOT 5.74G 415G 18K legacy
rpool/ROOT/opensolaris 5.74G 415G 5.61G /
rpool/dump 8.00G 415G 8.00G -
rpool/export 634K 415G 19K /export
rpool/export/home 615K 415G 19K /export/home
rpool/export/home/drapeau 596K 415G 596K /export/home/drapeau
rpool/swap 8.00G 423G 16K -

Sweet.  Now I've got a mediapool configured as a four-disk RAID-Z, and I have the rpool but right now it's only using one disk.  I want to mirror it now, using the 2nd 1.5TB disk's extra space.  I'll do that right now, then ask ZFS for status (I'll omit ZFS's status report on the mediapool because we just saw that).  Oh, and I'll make sure that mirrored rpool is bootable; ZFS will remind me to do it, so I'll include my steps here:

drapeau@blackfoot:$ pfexec zpool attach rpool c1t0d0s0 c1t1d0p1
Please be sure to invoke installgrub(1M) to make 'c1t1d0p1' bootable.

drapeau@blackfoot:$ pfexec installgrub -m /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c1t1d0s0

Updating master boot sector destroys existing boot managers (if any).
continue (y/n)?y
stage1 written to partition 0 sector 0 (abs 48195)
stage2 written to partition 0, 267 sectors starting at 50 (abs 48245)
stage1 written to master boot sector

drapeau@blackfoot:$ zpool status
  pool: rpool
 state: ONLINE
status: One or more devices is currently being resilvered.  The pool will
        continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
 scrub: resilver in progress for 0h5m, 39.40% done, 0h9m to go
        NAME          STATE     READ WRITE CKSUM
        rpool         ONLINE       0     0     0
          mirror      ONLINE       0     0     0
            c1t0d0s0  ONLINE       0     0     0  84.1M resilvered
            c1t1d0p1  ONLINE       0     0     0  5.41G resilvered

errors: No known data errors
About 8 minutes later, zpool status reported that the 2nd drive in rpool was resilvered and I had a fully-mirrored rpool.  Now if one of the two drives fails, I can still boot the OS and replace the bad disk.  And with the mediapool, I'm protected against any one of the four disks failing.  I'm feeling nice and secure; it's unlikely that two disks will fail at once unless the whole computer goes up in flames.  I'll deal with backup later, maybe by looking into Zmanda or something.

This is great: to this point, I've decided how to set up my storage and protect it, I've installed the OS, and I've created my storage pools.

My next blog entry will describe how I set up the computer to share all that storage with the rest of the house.

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Thursday Dec 18, 2008

My Home Media Server on OpenSolaris + ZFS: Part 1

A couple of people gave me some good pointers after my last blog entry, in which I was saying that doing an ssh or vncviewer into my new OpenSolaris installation was taking a while.  They pointed out that it may be reverse DNS lookups, not something about the OpenSolaris box itself, and that reminded me that recently I had changed something else about my home network setup: I had two hubs/routers active.  So, that mystery's solved; things are looking much better now and doing an ssh into the OpenSolaris box doesn't take so long.  Moving on...

My mission: use the current release of OpenSolaris (2008.11) as the basis for the main fileserver for home.  Right now, we've got several computers that have external disks attached to them for extra storage (music, photos, movies, etc.) and I want to centralize that for a couple of reasons:

  1. Friends of mine lost their house to a wildfire; fortunately, they had stored all of their critical data on a single computer with lots of disk so when they had to evacuate the house they grabbed one box and didn't lose any critical data.  Laugh all you want; when The Big One comes, I want to be ready.
  2. I'd like to simplify the administration of our home machines.  This is home, for goodness' sake; I don't want to be hiring a system administrator to keep our stuff in order.
I'll document here what I'm doing to build the home server.  My intent is to use OpenSolaris, use ZFS to manage the disks and files, and to do it with a cheap computer that I build myself from off-the-shelf parts (as opposed to, say, buying a Dell computer).  Besides, I want to put a bunch of disks in that computer and it's hard for me to find a cheap computer from Dell or HP with a bunch of internal drive bays, but you can pretty easily buy a reasonable computer enclosure with plenty of internal drive bays.  Building yourself can save money, and I'm all about saving some money on this.

But first, I'm going to try this out on a computer that is known to work with OpenSolaris.  I'll get the setup running there to make sure that ZFS + OpenSolaris really is as easy and reliable as I think it is.  Once I'm convinced that works, I'll switch to my cheapo computer and see if OpenSolaris runs on that.

So here goes...

Step 1: Data Protection

I have four disks: two 1TB drives, two 1.5 TB drives.  I'll split the larger drives into two partitions: 500GB for the operating system and the remaining TB for the big bucket-o-storage.  (let's call it my media pool: ZFS pool used primarily for storing audio, video, and photos)

So my first decision to make is: how should I have ZFS protect my data against disk failure?  After all, I'm buying consumer-grade disk drives but the server will be on 24/7.  The disks will fail.  I don't want to lose my data just because I don't want to pay extra for more reliable disks.  I want the software (ZFS) to take care of the problem for me.  I start by looking at the ZFS Best Practices Guide to see what my options are.

I'm considering three options for ZFS protecting my data:
  1. mirror
  2. raidz (shorthand for "raidz1", meaning 1 error can happen and I don't lose data)
  3. raidz2 (meaning 2 errors can happen and I don't lose data)
The guide points me to this blog entry by Roch Bourbonnais which tells me that the tradeoff I need to make is space versus performance: mirroring gives me maximum performance but cuts my disk storage in half: 4 TB of storage over 4 disks would take 50% overhead to protect the data by mirroring, leaving me a 2TB storage pool for storing movies, photos, music, and the like.  I don't need super-high performance but I want as much usable space as I can get out of my disks, so I choose raidz which should give me about 3TB of usable space; I lose 1TB to data protection, which sounds fine to me.  Later, I may buy a fifth disk and use raidz2 to give me even more robust data protection, but I'm not going to do that right now.

Now that I've decided how to protect my data, I just need to create the appropriate partitions on the larger disks, and I'll be ready to install the OS.  I'll document that in my next blog entry.

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