ZIL Log on BBU RAID card

[lassiterb]

Was thinking about using two Intel 313 20G SLC SSD's in a RAID-1 on a Battery backed Areca ARC-1213-4I as a ZFS ZIL Log device. It seems that it could benefit from the 512MB cache on the raid card for improved speed. Does anyone here have any thoughts on such an implementation? Good Idea? Bad Idea? I am trying to get the best performance using what I have available since I cannot afford a STEC Zeusram.

Intended use would be for a vmware datastore to host Exchange 2010 and a few other Windows Server VMs.

 

[dave99]

could be interesting, since that first 512mb should be very quick (not that the ssd would be slow).

 

[omniscence]

Does the RAID controllers write cache also work for pass-through devices? That way you could use the mirroring (and checksum per ZIL device) at ZFS level.

 

[lassiterb]

Does the RAID controllers write cache also work for pass-through devices? That way you could use the mirroring (and checksum per ZIL device) at ZFS level.

Not, sure. I haven't found anything to say one way or the other on this card yet. I will do some testing of it as soon as the battery module for this card arrives.

 

[dave99]

I think they typically do if you set up each drive as a raid 0 rather than jbod, then mirror them in zfs.