Date: Tue, 28 Aug 2012 19:47:05 -0400 From: Andrew Young <ayoung@mosaicarchive.com> To: Josh Paetzel <josh@tcbug.org> Cc: "freebsd-hardware@freebsd.org" <freebsd-hardware@freebsd.org> Subject: Re: Support for Fusion IO drives? Message-ID: <3F6C1EB2-1EC4-4863-A5BF-093649D9D61C@mosaicarchive.com> In-Reply-To: <503D4F48.9020108@tcbug.org> References: <CAHMRaQerwM4FRnfkc-1Yaa7JUVjJJazDhhQ_JZzE_Wn5OzKL2Q@mail.gmail.com> <503D3026.6010901@ixsystems.com> <CAK6u07XeH%2BjTg2M4s%2BpP=-HNgmtNC==Bh4fbZqCVWo5O7_rbyg@mail.gmail.com> <503D4F48.9020108@tcbug.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Thanks for the great feedback Josh! The optimum size for an ssd zil device w= as still an open question for us. I'm really glad to hear that they don't ne= ed to be that big. What does zfs do with the zil if there is no dedicated zil device? Our serve= rs consist of a small sata drive that holds the OS and a boatload of larger d= rives on a sas bus. What I'm wondering is if I simply replace the OS disk wi= th an ssd will I get the same performance boost as if I added a dedicated ss= d zil?=20 Thanks! Andy On Aug 28, 2012, at 7:07 PM, Josh Paetzel <josh@tcbug.org> wrote: >>> -------- Original Message -------- >>> Subject: Support for Fusion IO drives? >>> Date: Tue, 28 Aug 2012 16:46:00 -0400 >>> From: Andy Young <ayoung@mosaicarchive.com> >>> To: freebsd-hardware@freebsd.org >>>=20 >>>=20 >>> We are investigating adding SSDs as ZIL devices to boost our ZFS write >>> performance. I read an article a while ago about iX Systems teaming up >>> with >>> Fusion IO to integrate their hardware with FreeBSD. Does anyone know >>> anything about supported drivers for Fusion IO's iodrives? >>>=20 >>> Thanks! >>>=20 >>> Andy >>> _______________________________________________ >>> freebsd-hardware@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-hardware >>> To unsubscribe, send any mail to >>> "freebsd-hardware-unsubscribe@freebsd.org" >>>=20 >>>=20 >>>=20 >>>=20 >=20 > I'll put on my iXsystems hat here, as well as my fast storage, ZFS and > Fusion-I/O hat. >=20 > The ZFS filesystem supports dedicated ZIL devices, which can accelerate > certain types of write requests, notably related to fsync. The VMWare > NFS client issues a sync with every write, and most databases do as > well. In those types of environments having a fast dedicated ZIL device > is almost essential. In other environments the benefits of a dedicated > ZIL range from non-existent to substantial. >=20 > A good dedicated ZIL device is all about latency. It doesn't need to be > large, in fact it will only ever handle 10 seconds of writes, so 10x > network bandwidth is worst case. (In most environments this means 20GB > is larger than needed). >=20 > Fusion-I/O cards are far too large to be cost effective ZIL devices. > Even though they do rock at I/O latency, the really fast ones are also > fairly large, so the $/GB on them isn't so attractive. There are better > options for ZIL devices. >=20 > Another consideration is the Fusion-I/O driver is fairly memory hungry, > which competes with memory ZFS wants to use for read caching. >=20 > Now as an L2ARC device, that's a whole different can of worms. >=20 > Command line used: iozone -r 4k -s 96g -i 0 -i 1 -i 2 -t 8 > Parent sees throughput for 8 readers =3D 1712399.95 KB/sec > L2 ARC Breakdown: 197.45m > Hit Ratio: 98.61% 194.71m > L2 ARC Size: (Adaptive) 771.13 GiB > ARC Efficiency: 683.40m > Actual Hit Ratio: 71.09% 485.82m >=20 > ~ 800GB test data, all served from cache. >=20 > If you are considering Fusion-I/O, the FreeBSD driver is generally not > released to the general public by Fusion-I/O, but can be obtained from > various partners. (I believe iXsystems is the only FreeBSD friendly > fusion-i/o partner but could be wrong about that) >=20 >=20 > --=20 > Thanks, >=20 > Josh Paetzel >=20
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3F6C1EB2-1EC4-4863-A5BF-093649D9D61C>