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Date: Mon, 22 Nov 2010 17:20:41 -0500
From: Jonathan <jonathan@kc8onw.net>
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To: Andrew Reilly <areilly@bigpond.net.au>
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Cc: stable@freebsd.org
Subject: Re: ZFS backups: retrieving a few files?
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On 11/22/2010 5:13 PM, Andrew Reilly wrote:
> On Mon, Nov 22, 2010 at 10:26:30AM -0500, Jonathan Stewart wrote:
>> On 11/22/2010 6:35 AM, Andrew Reilly wrote:
>>> Dump/restore doesn't work for ZFS.  I *think* that I'm running
>>> backups in the appropriate equivalent fashion: I take file
>>> system snapshots (both absolute == level 0) and relative
>>> (incremental), and zfs send those to files on the backup disk.
>>
>> This is actively discouraged, there is no recovery ability when
>> receiving zfs streams so 1 bad bit would invalidate your entire backup.
>
> Hmm.  Isn't that a problem that also affects the "sending
> snapshots" scheme that you describe, below?

When sending the snapshots to a new file system you know right away 
whether they are bad or not.  Otherwise you find out when you are trying 
to restore and your backups are bad...  A send could fail but you can 
always retry that, you can't retry anything when your trying to restore.

Jonathan