bernt at bah.homeip.net
Sat Nov 21 14:33:12 UTC 2009
George Davidovich said the following on 2009-11-21 10:52:
> On Sat, Nov 21, 2009 at 04:12:42AM +0100, Bernt Hansson wrote:
>> Matthew Seaman skrev:
>>> Bernt Hansson wrote:
>>>> I've been testing backups with dump, works well BUT
>>>> -L does not work. For example
>>>> dump -0 -a -u -L -f /mnt/dump.home.full /dev/ad0s2d
>>> I believe that you need to tell dump the mount point of the file
>>> system in order for it to create a snapshot, rather than the device
>>> file for the partition. (ie. snapshotting only makes sense on a
>>> mounted read-write filesystem).
> Actually, the above isn't correct. A device special is fine. From the
> dump(8) manpage:
> The file system to be dumped is specified by the argument filesystem
> as either its device-special file or its mount point (if that is in a
> standard entry in /etc/fstab).
> The criteria unique to live dumps is that /dev/ad0s2d must be already
> mounted, and there must be a .snap directory in its root. You've since
> changed your command, so I won't address what the problem might have
>>> Also, if you're dumping a snapshotted FS to a local file, then bump
>>> up the cachesize to improve performance a lot. Add '-C 32' to your
>> Ok. I've tested this
>> dump -1 -a -u -L -C 64 -h 0 -f /usr/home/bernt/disk2/dump.backup.home.2 /usr/home
> Was the change from 'dump -0' to 'dump -1' intentional?
> Dump levels are
> rarely chosen to be sequential, but a level of 1 or greater is generally
> performed after a level 0 dump.
Yes. I've done a level 0 dump.
>> The error is mksnap_ffs: Cannot create /usr/home/.snap/dump_snapshot:
>> Invalid argument dump: Cannot create /usr/home/.snap/dump_snapshot: No
>> such file or directory
The directory exist.
drwxrwx--- 2 root operator 512 16 Nov 19:19 .snap
> You've now specified what's likely a directory (/usr/home), not a
> device-special or mount point. Your choices of valid filesystems can be
> determined by running df(1) and examining the first and last columns.
> On a typical install those two columns might be:
> Filesystem Mounted on
> /dev/ad0s1a /
> devfs /dev # ignore this line
> /dev/ad0s1e /tmp
> /dev/ad0s1f /usr
> /dev/ad0s1d /var
> Pick one. I prefer device names.
This is from my original post
dump -0 -a -u -L -f /mnt/dump.home.full /dev/ad0s2d
ad0s2d is /usr/home
> FWIW, if you're going to be using dump regularly (i.e. multiple dump
> levels and/or multiple hosts) and dumping to files, I'd suggest a naming
> convention of
I am going to use it on a regular basis, at least that is my intention.
If I can get the -L flag to work
I see what you mean. But since I already have a script (tar) that takes
care of that.
> to save you the grief of date fragility, and give you a meaningful
> display in 'ls -l' when restoring. So, for a level 0 dump on your
> system, your commands might be:
> dump -0auL -C 64 -f $dumpdir/hostname-20091121-root-0 -h 0 /
> dump -0auL -C 64 -f $dumpdir/hostname-20091121-usr-0 -h 0 /usr
> dump -0auL -C 64 -f $dumpdir/hostname-20091121-var-0 -h 0 /var
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