NVMe for Slog - Is it overkill for a small environment?

[DaveFL]

Hey folks,

So there are a lot of recommendations for both the S3500 and S3700. Both seem to be highly regarded with the S3700 having a slight edge in speed and large edge in endurance.

Not a lot of talk about some of the newer PCIe offerings e.g. Intel P3700 or Intel 750.

Newegg currently has the 750 on sale - I'm just wondering for a Slog in a small environment where the use will be both NAS and VM are the NVMe drives overkill or will they make a large difference?

 

[depasseg]

Small or large isn't as relevant.

Do you have lots of sync writes and a spinning rust pool? If so, then a SLOG will help. NVMe is even better.

 

[DaveFL]

Small or large isn't as relevant.

Do you have lots of sync writes and a spinning rust pool? If so, then a SLOG will help. NVMe is even better.

Cyber's noob PDF mentions that there are some tools which can help in determining how a slog can benefit the pool. What are these tools and can they be applied in determining which slog is likely to perform best? Just trying to get a sense of how one can objectively decide or see which one of these would work best.

 

[depasseg]

I think the tool he might have been referring to is called "zilstat".

 

[cyberjock]

zilstat is definitely a big one for sync writes.

NVMe stuff is, right now, really expensive compared to a standard SSD. Even Intel SSDs that we recommend on the forums can do 200-300MB/sec. So unless you have 10Gb or many, many 1Gb interfaces on LAGG or MPIO, there's no performance gain from NVMe over SSD. So spending the money is really a waste unless you think you'll need NVMe later. Of course NVMe will be cheaper later too.

 

[DaveFL]

Thanks. It's pretty cool how the Slog work.The idea of being able to write your data directly

zilstat is definitely a big one for sync writes.

NVMe stuff is, right now, really expensive compared to a standard SSD. Even Intel SSDs that we recommend on the forums can do 200-300MB/sec. So unless you have 10Gb or many, many 1Gb interfaces on LAGG or MPIO, there's no performance gain from NVMe over SSD. So spending the money is really a waste unless you think you'll need NVMe later. Of course NVMe will be cheaper later too.

Thanks Cyber, any opinions between the S3500, S3610 and 3700? b3n.org seems to have done a pretty good comparison between the 3500 and 3700. From a "value" standpoint the 3500 is pretty good, not quite up there on endurance though.

 

[Ericloewe]

zilstat is definitely a big one for sync writes.

NVMe stuff is, right now, really expensive compared to a standard SSD. Even Intel SSDs that we recommend on the forums can do 200-300MB/sec. So unless you have 10Gb or many, many 1Gb interfaces on LAGG or MPIO, there's no performance gain from NVMe over SSD. So spending the money is really a waste unless you think you'll need NVMe later. Of course NVMe will be cheaper later too.

I was under the impression that NVMe's reduced latency was a very big boost to SLOG workloads, more so than raw throughput (which even mid-range consumer SSDs have plenty of).