Best Configuration for 8x480GB Datacenter SSDs

[Matt Mabis]

Hey All,

was wondering what would be the most ideal configuration for and 8 Drive SSD Config, I know there are a lots of options especially when dealing with Datacenter SSDs but trying to maximize my IO as much as possible and i would like to have space as a secondary need but i understand some configs take away more space for performance.

This is going to be used in an ESXi VM Storage area.

My Gut was aiming Raid 10 just for the pure IOP capabilites but i was wondering since SSDs do outperform normal drives do i go Raid Z2 or even Split VDEVS in Raid 5 or something like that...

Will Be on a Server with E5 Xeon with 6 Cores and HT with 96GB Ram and some other Raid Z2 Arrays (Main Storage and Backup around 50TB) sitting on a SAS-2008 Controller (Trying to to upgrade to 3008) The Drives are a mix between S3500 Intels and 845DC Samsungs 480GB Each.

I do have a Intel 750 NVME and could purchase a better NVME to frontend as a ZIL as i think an SLOG would be useless in this All-Flash Configuration.

Any thoughts would greatly be appreciated!

 

[MatthewSteinhoff]

With IOPS as your primary goal, there is only one choice: stripe of mirrors.

Now, if you have a certain IOPS requirement, you may be able to meet that goal with a more space efficient configuration using SSDs. But that's not your question.

Cheers,
Matt

 

[Matt Mabis]

@MatthewSteinhoff - Thanks for the confirmation, just curious with this kind of configuration do you think a ZIL is still needed? Would you recommend something else besides the Intel 750 NVME? i do have some SAS SSD's as well..

 

[MatthewSteinhoff]

SLOG is most effective when you have a slow disk pool and need immediate confirmation of writes. That's not your configuration. Your SSD pool is going to be blazingly fast to begin with.

Run the numbers to be sure but I suspect a four-wide SSD mirror pool would have better performance than any single SLOG device no matter how fast that device might be. If not, it'll be close.

You can easily add SLOG to an existing pool. I'd go without SLOG and, if testing looks good, put it in production. You can always add it later. The process is quick, easy and non-destructive.

Cheers,
Matt