Date: Thu, 12 Jun 2008 12:35:22 +0200 From: "Daniel Eriksson" <daniel_k_eriksson@telia.com> To: <freebsd-questions@freebsd.org> Cc: =?iso-8859-1?Q?Anders_H=E4ggstr=F6m?= <hagge.lists@intercorner.net> Subject: RE: FreeBSD + ZFS on a production server? Message-ID: <4F9C9299A10AE74E89EA580D14AA10A61A193E@royal64.emp.zapto.org> In-Reply-To: <1a5a68400806080604ped08ce8p120fc21107e7de81@mail.gmail.com> References: <1a5a68400806080604ped08ce8p120fc21107e7de81@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Anders Häggström wrote: > I plan to install a web server for production use and ZFS looks very > interesting, especially since it has built-in support for RAID and > checksum. ZFS is very nice, but slightly over-hyped imho. However, some of the hype is warranted and for some use cases ZFS is a much better fit than UFS. Despite what Wojciech Puchar says, ZFS checksumming can be very useful. I recently had two drives in a hardware RAID-5 array (8 x 1 TB on a Highpoint RocketRAID 2340) develop unreadable sectors seemingly at the same time. I'm not sure what caused it but the end result was a broken/unavailable array. To make a long story short I managed to get the drives to remap the bad sectors and bring the array back online. Since I had ZFS on the array I didn't have to wait for fsck to run (takes a very long time on a 7 TB array and requires a LOT of memory to even work), and after the pool had been scrubbed I had a list of files with bad checksums that I could restore from backup. With UFS I would have had silent data corruption. Beware, there have been reports of mmap not working properly together with ZFS. I'm not sure if this is still a problem and if it would affect a typical web server. It does not seem to affect any of my fileservers (exporting NFS). /Daniel Eriksson
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4F9C9299A10AE74E89EA580D14AA10A61A193E>