[EXTERNAL] Re: FreeBSD10 Stable + ZFS + PostgreSQL + SSD performance drop < 24 hours

[Slawa Olhovchenkov]

On Tue, Jun 13, 2017 at 06:24:34AM +0000, Caza, Aaron wrote:

> Slawa - thanks again for your suggestion but, unfortunately, same behavior:

np, thanks for check!

> (Server is Intel Core i5-2500K w 16GB ram and 2x Intel 520 120GB SSDs):
> 
> PostgreSQL test results immediately after reboot:
>  Timing is on.
>   count
> ----------
>  21568508
> (1 row)
> 
> Time: 53855.000 ms
> test$ uptime
>  7:51PM  up 2 mins, 1 user, load averages: 2.46, 0.88, 0.34
> test$ uname -a
> FreeBSD xyz.com 10.3-STABLE FreeBSD 10.3-STABLE #0 r307264M: Mon Jun 12 17:48:24 MDT 2017     aaronc at WFT:XYZ  amd64
> 
> PostgreSQL test results after ~5 hours:
> Timing is on.
>   count
> ----------
>  21568508
> (1 row)
> 
> Time: 737626.512 ms
> test$ uname -a
> FreeBSD xyz.com 10.3-STABLE FreeBSD 10.3-STABLE #0 r307264M: Mon Jun 12 17:48:24 MDT 2017     aaronc at WFT:XYZ  amd64
> test$ uptime
>  1:06AM  up  5:16, 1 user, load averages: 2.21, 2.59, 2.04
> 
> Perhaps if I was on stable/11 this would be of some benefit.
> Thanks for the response.  I happened across r307264; however, my understanding is that it applies to the FreeBSD 11 and I'm using FreeBSD 10.

This commit (ZFS ARC comression support) was MFC on stable/11 and
stable/10, so you don't need check stable/11.