I too am using ZFS, and I can honestly say that ZFS works great, up to a point.
rsync does seem to take up an inordinate amount of resources, but in a smaller
shop like mine, it's been tolerable. I think it would work in a larger shop
too, but the system resource requirements (CPU/RAM) would grow larger than what
you would expect normally. I've had a couple of instances of performance
issues in my setup, where over time, rsync was uploading data to the system
faster than zfs could process it, and so I'd watch my load go through the roof
(8.00+ on a quad core system), and I would have to stop BackupPC for an hour or
so, so that ZFS could catch up, but other than that, this system has actually
handled it fairly well.
What I really like about ZFS though, is the deduplication coupled with
compression. I've disabled compression in BackupPC to allow ZFS to properly do
the dedup & compression (enabling compression in BackupPC kills ZFS' dedup
ability, since it messes with the checksums of the files), and I'm getting
numbers in the range of 4.xx deduplication. My ZFS array is 1.12TB in size,
yet, according to BackupPC, I've got 1800GB in fulls, and 2400GB in
incrementals. When I query the array for actual disk usage, it says I'm using
557GB of space... Now that's just too cool.
Thanks,
--Mark
-----Original Message-----
From: Tim Connors [mailto:tconnors AT rather.puzzling DOT org]
Sent: Monday, December 16, 2013 10:00 PM
To: General list for user discussion, questions and support
Subject: Re: [BackupPC-users] What file system do you use?
On Mon, 16 Dec 2013, Timothy J Massey wrote:
> One last thing: everyone who uses ZFS raves about it. But seeing as
> (on
> Linux) you're limited to either FUSE or out-of-tree kernel modules (of
> questionable legality: ZFS' CDDL license is *not* GPL compatible),
> it's not my first choice for a backup server, either.
I am using it, and it sucks for a backuppc load (in fact, from the mailing
list, it is currently (and has been for a couple of years) terrible on an rsync
style workload - any metadata heavy workload will eventually crash the machine
after a couple of weeks uptime. Some patches are being tested right now out of
tree that look promising, but I won't be testing them myself until it hits
master 0.6.3.
Problem for me is that it takes about a month to migrate to a new filesystem.
I migrated to zfs a couple of years ago with insufficient testing. I should
have kept on ext4+mdadm (XFS was terrible too - no faster than ext4, and given
that I've always lost data on various systems with it because it's such a flaky
filesystem, I wasn't gaining anything).
mdadm is more flexible than ZFS, although harder to configure. With
mdadm+ext4, you can choose any disk arrangement you like without being
limited to simple RAID-Z(n) arrangements of equal sized disks. That said, I do
prefer ZFS's scrubbing compared to mdadm's, but only slightly. If I was
starting from scratch and didn't have 4-5 years of backup archives, I'd tell
backuppc to turn off compression and munging of the pool, and let ZFS do it.
I used JFS 10 years ago, and "niche buggy product" would be my description for
it. Basically, go with the well tested popular FSs, because they're not as bad
as everyone makes them out to be.
--
Tim Connors
------------------------------------------------------------------------------
Rapidly troubleshoot problems before they affect your business. Most IT
organizations don't have a clear picture of how application performance affects
their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, &
PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro!
http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
------------------------------------------------------------------------------
Rapidly troubleshoot problems before they affect your business. Most IT
organizations don't have a clear picture of how application performance
affects their revenue. With AppDynamics, you get 100% visibility into your
Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro!
http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
|
