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#275786 - 07/02/2006 23:03 Which filesystem?
genixia
Carpal Tunnel

Registered: 08/02/2002
Posts: 3411
I'm rebuilding my home server. It will have 2x80GB IDE drives (previously existing RAID1 array) and 4x250GB SATA300 drives set up as RAID5.

On top the RAID arrays I am going to run LVM. I like the flexibility that LVM affords, and I really like the snapshot feature which will be useful for server virtualisation.

On top of that though... which filesystem? Obviously it has to be journalling. The CPU is going to be busy enough rebuilding arrays anyway. I don't want to wait hours for filesystem checks too! The old ext2 on RAID1 took long enough to fsck a 60GB partition. I hate to think how long a 720GB would take in addition.

Ext3 would be the obvious solution. But is it the best? Other options would be Reiser, XFS and JFS. I'm also open to running different filesytems on different logical volumes to match performance to intended use.

The large RAID5 array is going to be /home. Aside from typical flotsam and jetsom that ends up in /home, there will be lots of large media files there - mp3s and mpegs from my replaytvs. Everything else will be on the RAID1 array - /, /boot, /usr, /swap, /var, /tmp.
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Mk2a 60GB Blue. Serial 030102962 sig.mp3: File Format not Valid.

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#275787 - 07/02/2006 23:15 Re: Which filesystem? [Re: genixia]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
I've been a fan of ReiserFS for a while, as it just seems to work so much better then ext2/3 in situations where a lot of files might be in the same directory. For me this comes in handy with maildir mailboxes across the system, but might also be handy on a media system. I also trust the recovery tools to get things back if something goes horribly wrong, having once rebuilt a filesystem after a raid 5 meltdown of 1 failed drive and a second with a few bad areas. Once I forced the raid back online, reiserfs tools quickly got back everything possible.

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#275788 - 07/02/2006 23:48 Re: Which filesystem? [Re: drakino]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
On the other hand, I've had some extraordinarily bad experiences with ReiserFS, including with their recovery tools. The lack of FS-specific backup and recovery tools bothers me, too, perhaps needlessly.

I have had some good experience with XFS, and the fact that it can be grown easily might be a plus for your SAN-including plans.

I've had no problems with ext3, but it's not particularly advanced.

I have no real experience with JFS.
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Bitt Faulk

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#275789 - 08/02/2006 00:25 Re: Which filesystem? [Re: genixia]
Robotic
pooh-bah

Registered: 06/04/2005
Posts: 2026
Loc: Seattle transplant
Would this link be helpful?
http://en.wikipedia.org/wiki/Comparison_of_file_systems

I don't have any specific info to give you and I'm sure that most are better informed than I.
Searched a little on Slashdot for 'file system' under the Linux index for you, but didn't find any conclusive articles.
I'm sure I've seen posts on slashdot regarding this topic (slashdot being a haven for Linux lovers, afterall) but my search-fu isn't strong tonight.
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10101311 (20GB- backup empeg)
10101466 (2x60GB, Eutronix/GreenLights Blue) (Stolen!)

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#275790 - 08/02/2006 00:49 Re: Which filesystem? [Re: genixia]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14493
Loc: Canada
I use ext3 exclusively here, mostly for the reduced hassle: all distros and boot CDs support it "out of the box".

But it sucks for performance compared with XFS / JFS.

ReiserFS is actually two different file systems right now: Reiser3 and Reiser4. The latter is too new to be stable, and the former is inferior to XFS/JFS, but existed in Linux before any of its rivals.

Cheers

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#275791 - 08/02/2006 01:18 Re: Which filesystem? [Re: mlord]
genixia
Carpal Tunnel

Registered: 08/02/2002
Posts: 3411
Forward-compatibility with distros is always a factor. In the past I've always brought up a new box on new disks, then added in the old disks to migrate data across. With only RAID1 this works well. Obviously this gets harder with RAID5 because you need all the disks in the array (you can't just mount a degraded half like you can with RAID1), and the number of disks is higher. I'm hoping that the recent mdadm tools and LVM will enable me to grow the RAID5 array as necessary in the future. That all being said, I don't see XFS, JFS or Reiser being dropped from mainline distros anytime soon and I'm only going to run mainline distros on a fileserver - I'll leave the esoterics for the desktop.

I'm still not sure how much I care about performance versus convenience and reliability. For the RAID5 array, read performance is a bigger issue than write - mostly the data is static. Grabbing shows off of the replaytvs is severely bandwidth limited by the replaytvs themselves. Writing mp3s is going to be CPU limited. And it's not as if this box is going to be serving many people either.

The smaller RAID1 system array is going to need better write performance. syslog.

A month or two ago I saw an in-depth benchmarking of all of these filesystems, specifically with RAID. I wish I could find it now.
_________________________
Mk2a 60GB Blue. Serial 030102962 sig.mp3: File Format not Valid.

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#275792 - 08/02/2006 04:21 Re: Which filesystem? [Re: genixia]
tonyc
carpal tunnel

Registered: 27/06/1999
Posts: 7058
Loc: Pittsburgh, PA
*As I type this*, I'm going through pretty much the same thing with my main server. Here's how I'm setting mine up:

4 identical physical disks (4 x 320GB SATA)

3 RAID arrays, across all 4 disks:

Small RAID1 (200MB)
... logical partition
...... /boot (ext3)
Small-ish RAID0 (5GB)
... LVM volume group
...... swap
...... /tmp (reiserfs)
Big-ass RAID5 (the rest of the space)
... LVM volume group
...... / (reiserfs)
...... /home (reiserfs)
...... /music (jfs)
...... /photo (jfs)
...... /video (jfs)

(the latter 3 possibly on the same logical volume)

So, the idea is, simple mirroring for the boot partition, simple striping for the "don't care if they die, but need the speed" partitions, and RAID5 for general use. Within the RAID5, partitions with smaller files will be reiserfs (reiser3), and larger (media) files will go on JFS. My reason for this was based on this benchmark test and one other I've lost the link to, where the conclusions were: reiser for small files / general use, xfs for the absolute fastest write speeds with larger files, and jfs for the fastest read speeds with larger files. The write performance of jfs isn't much lower than xfs, certainly not so low as to trade off read speed for my media.

I recognize a couple anecdotal benchmarks don't prove one or the other is better, but it's enough for me to make my decision.

Back to the adventure (on install CD 3 of 4 now...)
_________________________
- Tony C
my empeg stuff

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#275793 - 12/02/2006 11:47 Re: Which filesystem? [Re: genixia]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14493
Loc: Canada
Quote:
I'm rebuilding my home server. It will have 2x80GB IDE drives (previously existing RAID1 array) and 4x250GB SATA300 drives set up as RAID5.

On top the RAID arrays I am going to run LVM. I like the flexibility that LVM affords, and I really like the snapshot feature which will be useful for server virtualisation.

On top of that though... which filesystem?


I have just received a box here, with 12 300GB SATA drives installed. I expect that I'll be setting up RAID5 over LVM on it within a few weeks, and it'll be interesting to see what kind of performance it is capable of..

Cheers

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#275794 - 12/02/2006 17:03 Re: Which filesystem? [Re: mlord]
genixia
Carpal Tunnel

Registered: 08/02/2002
Posts: 3411
Oh, I am so jealous. That should yield about 3.07TB in RAID5!

I'd be tempted to try RAID6 with that many drives though, or at least reserving one as a hot spare. You'd still get about 2.79TB.

I take it that this is work-related and on someone-elses dollar. Can you tell us which sata card you're using?

Here's my bonnie++ test using 10GB logical volumes.
Code:

Version 1.03 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
genixia-ext2-4k 2049M 34531 82 74377 16 17483 5 23804 60 57312 10 436.0 1
genixia-ext3-4k 2049M 31148 75 68173 20 21928 6 28116 68 54798 10 364.1 1
genixia-jfs-4k 2049M 33759 82 70475 16 19181 5 23839 49 50013 9 466.9 1
genixia-reiser-4k 2049M 34656 78 67953 23 21457 6 24017 60 52841 11 417.0 0
genixia-xfs-4k 2049M 35217 81 72467 22 19437 6 24457 56 56003 10 431.5 1
genixia-ext3-4k-noatime 2049M 32251 75 60789 18 22492 7 28932 61 56562 11 388.6 0
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
genixia-ext2-4k 16 3815 99 +++++ +++ +++++ +++ 3880 96 +++++ +++ 11239 99
genixia-ext3-4k 16 2809 98 +++++ +++ +++++ +++ 2799 97 +++++ +++ 6702 95
genixia-jfs-4k 16 1163 0 +++++ +++ 546 0 511 0 +++++ +++ 342 0
genixia-reiser-4k 16 23224 99 +++++ +++ 25527 100 22164 100 +++++ +++ 22071 98
genixia-xfs-4k 16 1353 14 +++++ +++ 1381 11 1397 16 +++++ +++ 579 6
genixia-ext3-4k-noatime 16 2791 99 +++++ +++ +++++ +++ 2816 99 +++++ +++ 6145 96

_________________________
Mk2a 60GB Blue. Serial 030102962 sig.mp3: File Format not Valid.

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#275795 - 12/02/2006 17:19 Re: Which filesystem? [Re: genixia]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14493
Loc: Canada
Quote:
Can you tell us which sata card you're using?


Some custom motherboard thing, in a 2U rackmount.

But on an other note, I expect to be taking on maintenance of the Linux Marvell SATA driver for a while. Apparently lots of people use Marvell controllers for large RAIDs, and I've heard varying reports about the (un)reliability of the driver (seems to vary by exact chipset version).

Cheers

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