Hugh Saunders wrote: > On Sat, May 24, 2008 at 4:00 PM, <[EMAIL PROTECTED]> wrote: >> > cache improve write performance or only reads? >> >> L2ARC cache device is for reads... for write you want >> Intent Log > > Thanks for answering my question, I had seen mention of intent log > devices, but wasn't sure of their purpose. > > If only one significantly faster disk is available, would it make > sense to slice it and use a slice for L2ARC and a slice for ZIL? or > would that cause horrible thrashing?
I wouldn't recommend this configuration. As you say it would thrash the head. Log devices mainly need to write fast as they only ever are read once on reboot if there's uncommitted transactions. Whereas cache devices require a fast read as the write can be done slowly and asynchronously. So a common device sliced for use as both purposes wouldn't work well unless it was both fast read and write and had minimal seek times (nvram, ss disk). Neil. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
