> I think the size of the ZIL log is basically irrelevant That was the understanding I got from reading the various blog posts and tuning guide.
> only a single SSD, just due to the fact that you've probably got dozens of > disks attached, and you'll probably use multiple log devices striped just for > the sake of performance. I've got 72 (possibly 76) 15k RPM 300GB and 600GB SAS drives and my head has 16 GB of RAM though that can be increased at any time to 32GB. My current plan is to use 4 x 32GB SLC write optimized SSD's in a striped mirrors configuration. I'm curious if anyone knows how ZIL slog performance scales. For example- how much benefit would you expect from 2 SSD slogs over 1? Would there be a significant benefit to 3 over 2 or does it begin to taper off? I'm sure a lot of this is dependent on the environment- but rough ideas are good to know. Is it safe to assume that a stripe across two mirrored write optimized SSD's is going to give me the best performance for 4 available drive bays (assuming I want the ZIL to remain safe)? > Is it even physically possible to write 4G to any device in less than 10 > seconds? I wasn't actually sure the 10 second number was still accurate- that was definitely part of my question. If it is- then yes- I could never fill a 32 GB ZIL, let alone a 64GB one. Thanks for all of the help and advice. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
