ZFS

Arnaud Houdelette arnaud.houdelette at tzim.net
Fri Oct 31 06:59:01 PDT 2008


Louis Kowolowski a écrit :
> <div class="moz-text-flowed" style="font-family: -moz-fixed">On Oct 
> 30, 2008, at 2:55 PM, Lorenzo Perone wrote:
>> On 22.10.2008, at 17:38, Freddie Cash wrote:
>>> Personally, we use it in production for a remote backup box using 
>>> ZFS and
>>> Rsync (64-bit FreeBSD 7-Stable from August, 2x dual-core Opteron 
>>> 2200s, 8
>>> GB DDR2 RAM, 24x 500 GB SATA disks attached to two 3Ware 9650/9550
>>> controllers as single-disks).  Works beautifully, backing up 80 FreeBSD
>>> and Debian Linux servers every night, creating snapshots with each run.
>>> Restoring files from an arbitrary day is as simple as navigating to the
>>> needed .zfs/snapshot/<snapname>/<path>/ and scping the file to 
>>> wherever.
>>> And full system restores are as simple as "boot livecd, 
>>> partition/format
>>> disks, run rsync".
>>
>>
>> So your system doesn't suffer panics and/or deadlocks, or you just
>> cope with them as "collateral damage" (which, admitted, is less of
>> a problem with a logging fs)?
>>
>> If that's the case, would you share the details about what you're using
>> on that machine (RELENG_7?, 7_0? HEAD?) and which patches
>> /knobs You used? I have a similar setup on a host which
>> backs up way fewer machines and locks up every... 3-9 weeks or so.
>> That host only has about 2GB ram though.
>>
> I have a system which is sort of similar in production at work.
> I have the following tunables (for ZFS) set:
> zfs_load="YES"
> vm.kmem_size_max="1024M"
> vm.kmem_size="1024M"
> vfs.zfs.arc_min="16M"
> vfs.zfs.arc_max="384M"
>
> [lkowolowski at release lkowolowski 76 ]$ uname -a
> FreeBSD release.pgp.com 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0: Wed 
> Sep  3 12:18:57 PDT 2008     
> root at release.pgp.com:/usr/obj/usr/src/sys/GENERIC  amd64
> [lkowolowski at release lkowolowski 77 ]$
>
> This box has 2G of RAM, and 8.5T in ZFS spread across 8 RAID1 mirrors 
> in an EonStore Fiber array (direct attach).
>
> It's been rock solid and stores all of our build collateral.
>
> -- 
> Louis Kowolowski                                louisk at cryptomonkeys.com
> Cryptomonkeys:                      http://www.cryptomonkeys.com/~louisk
>
> Making life more interesting for people since 1977
>

I use ZFS since 7.0-RELEASE. I'm currently using latest stable.
Ok the load is not as a production one, as the box is used as a home 
server (NAS), but the hardware is limited too (only 512MB of RAM, 
mono-core A64 3200+, motherborad integrated sata controler).
I tried to stress the filesystem a bit with multiple simultaneous 
rsyncs. No glitches. The only failures was when swap was on a zvol 
instead of the system drive. Even with more ram, it regularely ended in 
panics or deadlocks (most of the time, deadlocks) under "high" load.

Not sure of anything here, but you might want to try with non-zfs swap - 
on another drive(s) or dedicated slices ?

Arnaud Houdelette



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