tmpfs out of space (ZFS related?)

[Eir Nym]

On 22 November 2010 00:22, Ivan Voras <ivoras at freebsd.org> wrote:
> I got a curious error today while starting PostgreSQL, complaining about
> "out of space" errno while creating lock file on /tmp.
>
> /tmp on this machine is mounted as tmpfs and indeed, here is the statistic:
>
> biggie:/# df -i
> Filesystem    1M-blocks  Used  Avail Capacity iused     ifree %iused Mounted
> on
> /dev/mfid0s1a      9912  5193   3926    57%  306079   1012831   23%   /
> devfs                 0     0      0   100%       0         0  100%   /dev
> fdescfs               0     0      0   100%       4     11092    0% /dev/fd
> tmpfs                 0     0      0   100%       9         0  100%   /tmp
> tank             376044     0 376044     0%       4 770138347    0%   /tank
> tank/ports       376658   614 376044     0%  145919 770138347    0%
> /usr/ports
> tank/mysql       376073    29 376044     0%     102 770138347    0%
> /var/db/mysql
> tank/pgdata90    400469 24425 376044     6%    1047 770138347    0%
> /tank/pgdata90
>
> On the other hand, "top" reports this:
>
> last pid: 79667;  load averages:  0.08,  0.68,  0.77    up 1+09:12:13
> 00:11:33
> 44 processes:  1 running, 43 sleeping
> CPU:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
> Mem: 13M Active, 46M Inact, 15G Wired, 232K Cache, 1458M Buf, 8358M Free
> Swap: 1024M Total, 1024M Free
>
> Note the "8358M free" report.
>
> The server has ZFS and was doing IO intensive database work on it; the 8 GB
> free memory comes from PostgreSQL being restarted and freeing the memory
> (but failing to start again...).
>
> Starting PostgreSQL gets me this message:
> Nov 22 00:18:24 biggie postgres[79696]: [1-1] FATAL:  could not write lock
> file "/tmp/.s.PGSQL.5432.lock": No space left on device
>
> This is 8-STABLE amd64.
>
> Running "touch /tmp/abc" works, and creates a file. Running "echo abc >
> /tmp/abc" doesn't return an error but *doesn't write anything to the file*,
> just creates a directory entry.
>
> The status doesn't change over time, i.e. "df" on tmpfs always shows "0
> free".
>

Which type of MFS do you use? I think you shold use "swap-backed" for
your /tmp, not "malloc-based". Last type is only for in-kernel file
system.

> _______________________________________________
> freebsd-current at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe at freebsd.org"
>