[OpenIndiana-discuss] Fileserver performance with log and cache devices?

[Doug Hughes]

On 12/1/2011 3:15 PM, David Brodbeck wrote:
> On Thu, Dec 1, 2011 at 8:09 AM, Geoff Flarity<geoff.flarity at gmail.com>wrote:
>
>> My advice would be to max out your RAM (for ARC) before you bother
>> with a ZIL, or L2ARC.  Where a fast SSD for a ZIL really shines is
>> random synchronized writes. IE a database transaction. You'll notice
>> this when you run filebench and look at the results. I'm not sure how
>> NFS handles FSYNC and DSYNC to be honest.
>>
> NFS does a *lot* of synchronous writes and will probably benefit from a
> fast ZIL device.
>
It's particularly valuable data for heavy meta-data intensive things 
with NFS, which includes deleting directories with rm -r and creating or 
updating lots of small files. NFS commits beat on the ZIL.