Hi Scott,
Well, we can't be sure OP's only got one core.
In fact, we can, Sean posted what top -b -n 1 says. There was only one CPU line.
the number of cores, it's the IO subsystem is too slow for the load. More cores wouldn't fix that.
While I agree on the IO, more cores would definitely help to improve ~6.5 load average.
My production PG server that runs ONLY pg has 222 processes on it. It's no big deal. Unless they're all trying to get cpu time, which generally isn't the case.
222 / 8 cores = ridiculous 27 processes per core, while the OP has 239.
More likely just a slow IO subsystem. Like a single drive or something. adding drives in a RAID-1 or RAID-10 etc usually helps.
Absolutely.
This is kernel buffers, not pg buffers. It's set by the OS semi-automagically. In this case it's 325M out of 32 Gig, so it's well under 10%, which is typical.
You can control the FS buffers indirectly by not allowing running processes to take too much memory. If you have like 40% free, there are good chances the system will use that memory for buffers. If you let them eat up 90% and swap out some more, there is no room for buffers and the system will have to swap out something when it really needs it.
Not true. Linux will happily swap out seldom used processes to make room in memory for more kernel cache etc. You can adjust this tendency by setting swappiness.
This is fine until one of those processes wakes up. Then your FS cache is dumped.
It's 30G btw,
Yeah, I couldn't believe my eyes :-)
> 3G of cached swap and it's not swap that's cached, it's the kernel using extra memory to cache data to / from the hard drives.
Oh please.. it *is*: http://www.linux-tutorial.info/modules.php?name=MContent&pageid=314
It's normal, and shouldn't worry anybody. In fact it's a good sign that you're not using way too much memory for any one process.
It says exactly the opposite.
Really? I have eight cores on my production servers and many batch jobs I run put all 8 cores at 90% for extended periods. Since that machine is normally doing a lot of smaller cached queries, it hardly even notices.
The OP's machine is doing a lot of write ops, which is different.
Yes, more hard drives / better caching RAID controller.
+1 BTW, nearly full file system can be another source of problems. Cheers, Mike -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
