Re: Who is causing all this i/o?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 05/20/2011 02:14 PM, Craig James wrote:
Our development server (PG 8.4.4 on Ubuntu server) is constantly doing something, and I can't figure out what. The two production servers, which are essentially identical, don't show these symptoms. In a nutshell, it's showing 10K blocks per second of data going out, all the time, and essentially zero blocks per second of input.
...
There are people on this list better equipped than I to get into the guts of diagnosis, but a quick Google shows you aren't the only person to see high IO with disk activity. There are suggestions that a db with lots of temp-table creation and nothing triggering a vacuum could be related. Another thread suggested that bloated system tables could be to blame. Others look at the stats collectors. Groping a bit in the dark, I would try...

Checking PG logs for info - especially anything indicating that vacuum isn't running or isn't being triggered.

Manual vacuum.

Vacuum full of system tables (pg_catalog - especially pg_class and pg_attribute) - possibly followed by a reindex all followed by a manual vacuum. Note: IIRC, that file is shared across databases so you will need to clean each one.

Reset stats collector at startup.

Check system after each change and report back if anything improves or degrades the situation.

Cheers,
Steve




--
Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-admin


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux