On Wed, Apr 18, 2012 at 05:09:29PM -0700, Josh Berkus wrote:
> On 4/12/12 8:47 AM, Steve Crawford wrote:
> > On 03/30/2012 05:51 PM, Josh Berkus wrote:
> >>
> >> So this turned out to be a Linux kernel issue. Will document it on
> >> www.databasesoup.com.
> > Anytime soon? About to build two Post
On 4/12/12 8:47 AM, Steve Crawford wrote:
> On 03/30/2012 05:51 PM, Josh Berkus wrote:
>>
>> So this turned out to be a Linux kernel issue. Will document it on
>> www.databasesoup.com.
> Anytime soon? About to build two PostgreSQL servers and wondering if you
> have uncovered a kernel version or s
On 03/30/2012 05:51 PM, Josh Berkus wrote:
So this turned out to be a Linux kernel issue. Will document it on
www.databasesoup.com.
Anytime soon? About to build two PostgreSQL servers and wondering if you
have uncovered a kernel version or similar issue to avoid.
Cheers,
Steve
--
Sent via
>> Read cache of course does not need to be flushed and can simply be
>> dumped when the memory is needed, and so Linux will keep more or
>> less unlimited amounts of read cache until it needs the memory for
>> something else
>
> Right, that's the normal behavior. Except not on this machine
> This may just be a typo, but if you really did create write (dirty)
> block device cache by writing the pg_dump file somewhere, then that
> is what it's supposed to do ;)
The pgdump was across the network. So the only caching on the machine was read
caching.
> Read cache of course does not
This may just be a typo, but if you really did create write (dirty) block
device cache by writing the pg_dump file somewhere, then that is what it's
supposed to do ;) Linux is more aggressive about write cache and will allow
more of it to build up than e.g. HP-UX which will start to throttle
proces
On Tue, Mar 27, 2012 at 5:06 PM, Joshua Berkus wrote:
> In an effort to test this, we deliberately ran a pg_dump. This did grow the
> cache to all available memory, but Linux rapidly cleared the cache (flushing
> to disk) down to 25GB within an hour.
This would happen if some queries (or some
