OpenZFS on OS X

Hello Guys,

I'm using ZFS on a ZRAID 1 with 4x4TB WD RED and I've two bays on the enclosure so I've putted two 480GB SSD as pool cache.

What is the best configuration to make intensive use of SSD caching.I'm not experiencing a big boost in performances and I'm wondering if is there a way to use the SSD more intensively. I'm also wondering if two SSD as cache disks works better then one or the second is irrelevant.

Thanks for your help,

Gabriele

I'm using an 80Gb Intel 320 SSD as the cache drive, and surprisingly I'm not really seeing much of a difference in performance. Would be interested to know if there's a best-practice here too.

So far as I know l2arc is not all that effective unless your workload drives it. The cache has to be warmed up and is not persistent across reboots right now (there is a persistent l2arc change being designed upstream).

slog is only for sync writes so has limited application.

Cheers
Brendon

I have 20gb mirrior as log and 80gb non mirrior as cache. I have noticed a difference in performance; however, I never turn off the system. Also it only helps with some tasks.

Curious here as well and noticed that the OPs original question was never answered.

luminousdolphin wrote:Curious here as well and noticed that the OPs original question was never answered.

A good source of information http://docs.oracle.com/cd/E19253-01/819-5461/, also http://www.solarisinternals.com/wiki/in ... ning_Guide.

The advice in those links is generally applicable to O3X and all other ZFS implementations. You will quickly learn that there are lots of things that can be done with ZFS, as to subjective concepts such as "best practice" well the answer inevitably varies with the use case. Up to you to test and evaluate your usage carefully.

I have one system with slog and l2arc running, and I'm sure its a little better in performance. I also have my main system that has none, and performance is great. You are better to have loads of RAM and run a larger ARC in general. There is a thing called persistent L2ARC coming downstream (who knows when), that may alter the value proposition somewhat.

Cheers
Brendon