[OmniOS-discuss] Pliant/Sandisk SSD ZIL

[Dan McDonald]

On Feb 18, 2014, at 9:41 PM, Marion Hakanson <hakansom at ohsu.edu> wrote:

> Derek Yarnell wrote:
>>>> So we bought a new Dell R720xd with 2 Dell SLC SSDs which were shipped
>>>> as a Pliant-LB206S-D323-186.31GB via format.
> 
> Richard Elling wrote:
>>> Pliant SSDs (note: Pliant was purchased by Sandisk in 2011) are optimized 
> for
>>> lots of concurrent I/O operations. This is not the kind of workload 
> generated
>>> by the ZIL, which is more contiguous, single thread-like.
> 
> Derek Yarnell wrote:
>> I realize that they may not be as good as Stec/HGST ZeusRAM drives for
>> the slog.  I still can't wrap my head around that it is as bad as having
>> no discrete slog.
> 
> Hi Derek,
> 
> No better than with the ZIL running on the pool's HDD's?  Really?
> 
> Out of curiosity, what HBA is being used for these drives (and slog)
> in this R720xd, H710 or H310?  Something else?
> 
> I'm also looking at the R720xd here, though I was thinking of using the
> Intel DC S3700 SSD for a log device (in one of the internal flex-bay's),
> with the pool drives being of the 2.5" form-factor.

The H710 sticks you with HW-RAID.  Ick.

The H310 allows you to use raw SAS disks, BUT I've encountered problems with BIOS failing INT13 reads on H310 raw disks, which makes booting difficult.  (Also some Dell-issued disks require power entries in /kernel/drv/sd.conf.)

Just be cautious when using the Dell HBAs.

Dan