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Thread: Tracking disk writes?

Tracking disk writes?

From
Erik Jones
Date:
I've seen that I can get the total number of blocks read from disk over the lifetime of a database via the pg_stat_database view, and by taking successive readings I can track reads over time.  How can I track disk writes?


erik jones <erik@myemma.com>
sofware developer
615-296-0838
emma(r)



Re: Tracking disk writes?

From
Jim Nasby
Date:
On Mar 10, 2007, at 4:33 AM, Erik Jones wrote:
> I've seen that I can get the total number of blocks read from disk
> over the lifetime of a database via the pg_stat_database view, and
> by taking successive readings I can track reads over time.  How can
> I track disk writes?

Hey Erik...

That's not currently tracked anywhere, but it would be good
information to have. I suspect it could be added without a great deal
of difficulty by looking at what's done for tracking blocks read, as
well as another patch that added new statistics (I know there was one
for vacuum stats back last summer).

Also, someone on -hackers was recently looking into some stuff with
the bgwriter and added some logging code; I don't remember if they
also added some statistics.
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)

Re: Tracking disk writes?

From
Erik Jones
Date:
On Mar 24, 2007, at 1:06 PM, Jim Nasby wrote:

On Mar 10, 2007, at 4:33 AM, Erik Jones wrote:
I've seen that I can get the total number of blocks read from disk over the lifetime of a database via the pg_stat_database view, and by taking successive readings I can track reads over time.  How can I track disk writes?

Hey Erik...

That's not currently tracked anywhere, but it would be good information to have. I suspect it could be added without a great deal of difficulty by looking at what's done for tracking blocks read, as well as another patch that added new statistics (I know there was one for vacuum stats back last summer).

Also, someone on -hackers was recently looking into some stuff with the bgwriter and added some logging code; I don't remember if they also added some statistics.

Right on the usefulness part!!  Although, Tom's thoughts wrt to the bgwriter were that that would be the part that would make this non-trivial.

erik jones <erik@myemma.com>
software developer
615-296-0838
emma(r)