# Best drives to use for ZFS SLOG w/ 9300-8i



## absduser (Feb 7, 2020)

I am setting up a new server running FreeBSD 12.1 which will have a (non-boot) zpool with a SLOG. The SLOG drives will be running on a LSI (Broadcom) 9300-8i 12G SAS/SATA HBA card:
https://www.broadcom.com/products/storage/host-bus-adapters/sas-9300-8i

I'm wondering what drives people are using/liking that take full advantage of this card's speed and (12Gb/s) capability while also providing the write cache (power loss protection) required for the SLOG.

Thanks!


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## Phishfry (Feb 8, 2020)

I think instead of worrying about PLP you should invest in a viable system Battery Backup.
Personally I am using 512GB NVMe. One for SLOG and one for L2ARC.
I went this route because I had all 3 LSI controllers occupied on my 24 bay machine.
If I had to buy them again I would probably only use 256GB NVMe for each.

Some of this choice would come back to your zpool devices. Are you using hard drives or SSD?
An SSD for a zpool of hard drives seems like an appropriate SLOG but for a zpool of SSD's I would use an NVMe for SLOG.
That is my 2 cents from a new ZFS user.


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## Phishfry (Feb 17, 2020)

I saw you post on the mailing list with no replies. I am assuming you want actual drive recommendations.
If I had to use SAS drives I would use Toshiba PX02SM Series.
These are mid endurance and the PX02SMF040 offers 400GB of PLP protected storage.
Perfect for SLOG or L2ARC for my array size.








						Toshiba PX02SMF040 400GB SSD - Quick Benchmarks
					

Our quick benchmarks and review of the Toshiba PX02SMF040 400GB SSD SAS3. This time we preview some of our database test latency data.




					www.servethehome.com


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## gpw928 (Feb 17, 2020)

What sort of drives are you running for the zpool?  Will some, or all, of them be on the same SAS9300-8i controller?

There are two SFF8643 high density headers on the SAS9300-8i controller card, so breaking out to 4 x SAS connectors and 4 x SATA connectors is probably an option, as is 8 x SAS xor 8 x SATA.

As Phishfry implies, it's important for the performance (and especially the write latency) of a SLOG to be superior to the zpool.  If not, you are wasting your money (leave the ZIL in the default location, which is the zpool).


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## rootbert (Feb 18, 2020)

important sidenote: if you use ZFS with redundancy, also use SLOG with redundancy (mirror)!


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