|
[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]
|
Re: [PLUG] ZFS is not a backup
|
Sean Collins wrote:
> Had a user with an OS X box that was using ZFS to mirror a dataset.
> User had a hardware failure (disks were in the same enclosure) that
> corrupted the ZFS metadata. He had not archived his data, so once
> again we are left to remind others that RAID and other replication
> strategies are to prevent downtime. Nothing more!
>
> Not to mention, ZFS support on OS X has become very unofficial over
> the past few months. I use ZFS on my OS X laptop but I made an archive
> of all my data just in case something catastrophic happened.
>
> Thank You,
> Sean Collins
>
>
I've been playing with ZFS lately in a VM, yes Lots of misconceptions
about ZFS.
By itself ZFS includes volume management and a file system, but ZFS
alone is not RAID.
The RAID-Z component is what provides the redundancy, but as Jeff
Darcy blog points out here http://pl.atyp.us/wordpress/?p=1009 there
is controversy if RAID-Z is really RAID at all.
Conceptually it's easy to rebuild a mirror, or RAID 5 array, but the
argument is that rebuilding a ZFS disk requires traversing the entire
filesystem tree, so the rebuild could be more prone fail for other
unknown errors.
Still, the write performance is much better than RAID-5 , the RAID-5
write hole is plugged, snapshots are inexpensive and incur no
performance penalty, and the command-line management
tools are very easy to work with.
And yes, if your snapshotting locally, then use ZFS snapshot replication
http://www.cuddletech.com/blog/pivot/entry.php?id=984
to get the data onto another separate device.
Lee
begin:vcard
fn:Lee Marzke
n:Marzke;Lee
org:4AERO
adr;dom:;;;Collegeville;PA;19426
email;internet:lee@marzke.net
title:Consultant
tel;work:+1 800 393 5217
tel;fax:+1 484 348 2230
tel;cell:+1 610 564 4932
url:http://4aero.com/
version:2.1
end:vcard
___________________________________________________________________________
Philadelphia Linux Users Group -- http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
|
|