Avago LSI SAS 3008 & Intel SSD Timeouts

[Borja Marcos]

> On 03 Jun 2016, at 23:49, Steven Hartland <killing at multiplay.co.uk> wrote:
> 
> First thing would be to run gstat with -d to see if you're actually stacking up deletes, a symptom of which can be r/w dropping to zero.
> 
> If you are seeing significant deletes it could be a FW issue on the drives.

Hmm. I’ve suffered that badly with Intel P3500 NVMe drives, which suffer at least from a driver problem: trims are not coalesced. 
However I didn’t experience command timeouts. Reads and, especially, writes, stalled badly.

A quick test for trim related trouble is setting the sysctl variable vfs.zfs.vdev.bio_delete_disable to 1. It doesn´t require
a reboot and you can quickly compare results.

In my case, a somewhat similar problem in an IBM server was caused by a faulty LSI3008 card it seems. As I didn´t have spare LSI3008 cards
at the time I replaced it by a LSI2008 and everything works perfectly. Before anyone chimes in suggesting card incompatibility of some sort,
I have a twin system with a LSI3008 working like a charm. ;)







Borja.