Edward Ned Harvey wrote: >> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- >> boun...@opensolaris.org] On Behalf Of Arne Jansen >> >> There is absolutely no sense in having slog devices larger than >> then main memory, because it will never be used, right? > > Also: A TXG is guaranteed to flush within 30 sec. Let's suppose you have a > super fast device, which is able to log 8Gbit/sec (which is unrealistic). > That's 1Gbyte/sec, unrealistically theoretically possible, at best. You do > the math. ;-) > > That being said, it's difficult to buy an SSD smaller than 32G. So what are > you going to do?
I'm still building my rotational write delay eliminating driver and am trying to figure out how much space I can waste on the underlying device without ever running into problems. I need half the physical memory, or, under the assumption that it might be tunable, a maximum of my physical memory. It's good to know a hard upper limit. The more I can waste, the faster the device will be. Also, to stay in your line of argumentation, this super-fast slog is most probably a DRAM-based, battery backed solution. In this case it will make a difference if you buy 8 or 32GB ;) --Arne _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
