Re: "Leaking" disk space on FreeBSD servers - Mailing list pgsql-general

From Vick Khera
Subject Re: "Leaking" disk space on FreeBSD servers
Date
Msg-id CALd+dccaig0A9htvApoGYKHQ7TF9vr26d7qPaULRpPegvaFnZQ@mail.gmail.com
Whole thread Raw
In response to "Leaking" disk space on FreeBSD servers  (Dan Thomas <godders@gmail.com>)
Responses Re: "Leaking" disk space on FreeBSD servers
Re: "Leaking" disk space on FreeBSD servers
List pgsql-general

On Wed, Mar 20, 2013 at 7:49 AM, Dan Thomas <godders@gmail.com> wrote:
Not all of our servers are leaking space, it's only the more recently-installed systems. Here's a quick breakdown of versions:

FWIW, I do not observe this behavior. My database has very heavy write load, and old data is purged after it is aged about 7 months, so I do get lots of fragmentation. However, I do not have any disk space "phantom" loss.

How long does it take for you to accumulate this "leak"?  My first instinct is that you have unlinked files still referenced by some application. That is really the only way you get these discrepancies. lsof *should* have showed them to you.  Try fstat in case there's some bug in lsof.

Also, your tunefs output seems to be not from FreeBSD 9.1. Specifically, it is not emitting this line:

tunefs: soft update journaling: (-j)                       disabled

It is a very useful option to turn on for large file systems. I can recover a 6TB file system in about 5 seconds on a crash reboot with that on.



[root@d04]# ps axuw34214
USER    PID %CPU %MEM     VSZ    RSS TT  STAT STARTED    TIME COMMAND
pgsql 34214  0.0  0.5 5426964 154484  0- S    28Feb13 1:30.66 /usr/local/bin/postgres -D /u/data/postgres
[root@d04]# df -h /u/data
Filesystem          Size    Used   Avail Capacity  Mounted on
/dev/ufs/ramdisk    707G    137G    513G    21%    /u/data
[root@d04]# du -sh /u/data
137G /u/data
[root@d04]# uname -a
FreeBSD d04.m1e.net 9.1-RELEASE FreeBSD 9.1-RELEASE #1 r243808: Mon Dec  3 09:56:27 EST 2012     vivek@lorax.kcilink.com:/usr/obj/u/lorax1/usr9/src/sys/KCI64  amd64
[root@d04]# uptime
 9:50AM  up 74 days, 17:36, 1 user, load averages: 0.21, 0.18, 0.17
[root@d04]# psql --version
psql (PostgreSQL) 9.2.3
[root@d04]#

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