> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- > boun...@opensolaris.org] On Behalf Of Ray Van Dolson > > Are any of you using the Intel 320 as ZIL? It's MLC based, but I > understand its wear and performance characteristics can be bumped up > significantly by increasing the overprovisioning to 20% (dropping > usable capacity to 80%). > > Anyone have experience with this?
I think most purposes are actually better suited to disabling the ZIL completely. But of course you need to understand it and make an intelligent decision yourself in your particular case. Figure it like this... Suppose you have a 6Gbit bus. Suppose you have an old OS which flushes TXG's maximum every 30 sec (as opposed to the more current 5 sec)... that means the absolute max data you could possibly have sitting in the log device is 6gbit * 30sec = 180Gbit = 22 Gbytes. Leave yourself some breathing room, and figure a comfortable size is 30G usable. Intel 320's look like they start at 40G, so you're definitely safe overprovisioning 25% or higher. I cannot speak to any actual performance increase resulting from this tweak. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
