On Wed, Feb 29, 2012 at 7:28 AM, Stefan Keller <sfkeller@xxxxxxxxx> wrote: > 2012/2/29 Stefan Keller <sfkeller@xxxxxxxxx>: >> 2012/2/29 Jeff Janes <jeff.janes@xxxxxxxxx>: >>>> It's quite possible the vacuum full is thrashing your disk cache due >>>> to maintainance_work_mem. You can overcome this issue with the tar >>>> trick, which is more easily performed as: >>>> >>>> tar cf /dev/null $PG_DATA/base >>> >>> But on many implementations, that will not work. tar detects the >>> output is going to the bit bucket, and so doesn't bother to actually >>> read the data. >> >> Right. >> But what about the commands cp $PG_DATA/base /dev/null or cat >> $PG_DATA/base > /dev/null ? >> They seem to do something. For me they both give errors, because neither of them works on an directory rather than ordinary files. > > ...or let's try /dev/zero instead /dev/null: > tar cf /dev/zero $PG_DATA/base That does seem to work. So, does it solve your problem? Cheers, Jeff -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
