Use Intel P4600 NVMe 2TB as both SLOG and L2ARC

[gpastor]

Hi,

We are planning a new virtualization deployment for a customer. Virtualization hosts will be VMware 6.7 and storage array will be a shiny new Lenovo ThinkSystem SR650 which has an Intel P4600 NVMe 2TB (fixed configuraton from our provider, I can't chage that). I'm planning to make 2 partitions and use them as a SLOG and L2ARC respectively.

Is there any downside in having both SLOG and L2ARC on the same NVMe disk? Obviously if I had two separate devices for SLOG and L2ARC, performance will be better, but as I said, unfortunately I can't change that.

¿Have you any experience on this? ¿Any suggestions to better use this NVMe drive?

Thanks

 

[gea]

This would work and the P4600 would make a decent Slog/L2Arc.

The but is the price and the waste of space. Slog needs no more than 10-20 GB and L2Arc does not help much with enough RAM and should not be larger than 5-10x RAM.

With P4600 I would try to get a second one to build a Raid-1/10 Pool or use them as a special vdev to place metadata and some filesystem onto, see https://forums.servethehome.com/ind...ocation-classes-performance-benchmarks.26111/

An Intel 4801X -200 is faster (or the Optane 900 if you do not need guaranteed PLP), mabay even the 100GB Optane is on par.

 

[T_Minus]

Agreed, would go with 2xP4600 and 1x Optane

 

[gpastor]

This would work and the P4600 would make a decent Slog/L2Arc.

Hi, gea
Never tried to do this before, just wanted to be sure.

The but is the price and the waste of space. Slog needs no more than 10-20 GB and L2Arc does not help much with enough RAM and should not be larger than 5-10x RAM.

With P4600 I would try to get a second one to build a Raid-1/10 Pool or use them as a special vdev to place metadata and some filesystem onto, see https://forums.servethehome.com/ind...ocation-classes-performance-benchmarks.26111/

Caching metadata is an interesting idea, sure I will dig deeper in to this.

An Intel 4801X -200 is faster (or the Optane 900 if you do not need guaranteed PLP), mabay even the 100GB Optane is on par.

We will get an Optane 900 for the next Freenas server for our company. Looking forward to putting my hands on it!

Thanks!