On Tue, Jan 20 at 21:35, Eric D. Mudama wrote: > On Tue, Jan 20 at 9:04, Richard Elling wrote: >> >> Yes. And I think there are many more use cases which are not >> yet characterized. What we do know is that using an SSD for >> the separate ZIL log works very well for a large number of cases. >> It is not clear to me that the efforts to characterize a large >> number of cases is worthwhile, when we can simply throw an SSD >> at the problem and solve it. >> -- richard >> > > I think the issue is, like a previous poster discovered, there's not a > lot of available data on exact performance changes of adding ZIL/L2ARC > devices in a variety of workloads, so people wind up spending money > and doing lots of trial and error, without clear expectations of > whether their modifications are working or not.
Sorry for that terrible last sentence, my brain is fried right now. I was trying to say that most people don't know what they're going to get out of an SSD or other ZIL/L2ARC device ahead of time, since it varies so much by workload, configuration, etc. and it's an expensive problem to solve through trial an error since these performance-improving devices are many times more expensive than the raw SAS/SATA devices in the main pool. -- Eric D. Mudama edmud...@mail.bounceswoosh.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
