jhary at unsane.co.uk
Sat Aug 18 03:26:45 PDT 2007
Victor Sudakov wrote:
> Right now I am watching a dump:
> [root at admin ~] dump -b64 -5Lau /home
> DUMP: Connection to big.sibptus.tomsk.ru established.
> DUMP: Date of this level 5 dump: Sat Aug 18 14:02:16 2007
> DUMP: Date of last level 0 dump: Sun Aug 12 11:10:56 2007
> DUMP: Dumping snapshot of /dev/ad0s2f (/home) to /dev/nsa0 on host big
> DUMP: mapping (Pass I) [regular files]
> DUMP: mapping (Pass II) [directories]
> DUMP: estimated 3249348 tape blocks.
> at the same moment:
> [root at admin ~] snapinfo -v /home
> /dev/ad0s2f mounted on /home
> no snapshots found
> [root at admin ~] ll /home/.snap/
> total 0
> [root at admin ~]
> Is this normal? Does it mean that dump is not really dumping a
> snapshot though it says it is?
man dump (the section regarding -L) says
"The snapshot is unlinked as soon as the dump starts, and is thus
removed when the dump is complete." What this means to you is that the
snapshot is only visible on the file system for as long as it takes dump
to start reading from it, dump will have an open filehandle to the
snapshot so it can be unlinked from the filesystem and as soon as dump
closed its handle then the snapshot is removed. Similar to when you
delete a large logfile a program has open and forget to HUP/stop/restart
the program, the logfile's diskspace isnt released until the the program
closes its file handle.
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