On Thu, Jul 14, 2011 at 04:53:11PM +0300, Pasi Kärkkäinen wrote: > On Wed, Jul 13, 2011 at 11:32:14PM -0700, John R Pierce wrote: > > I've been asked for ideas on building a rather large archival storage > > system for inhouse use, on the order of 100-400TB. Probably using CentOS > > 6. The existing system this would replace is using Solaris 10 and > > ZFS, but I want to explore using Linux instead. > > > > We have our own tomcat based archiving software that would run on this > > storage server, along with NFS client and server. Its a write once, > > read almost never kind of application, storing compressed batches of > > archive files for a year or two. 400TB written over 2 years translates > > to about 200TB/year or about 7MB/second average write speed. The very > > rare and occasional read accesses are done by batches where a client > > makes a webservice call to get a specific set of files, then they are > > pushed as a batch to staging storage where the user can then browse > > them, this can take minutes without any problems. > > > > My general idea is a 2U server with 1-4 SAS cards connected to strings > > of about 48 SATA disks (4 x 12 or 3 x 16), all configured as JBOD, so > > there would potentially be 48 or 96 or 192 drives on this one server. > > I'm thinking they should be laid as as 4 or 8 or 16 seperate RAID6 sets > > of 10 disks each, then use LVM to put those into a larger volume. > > About 10% of the disks would be reserved as global hot spares. > > > > So, my questions... > > > > D) anything important I've neglected? > > > > Remember Solaris ZFS does checksumming for all data, so with weekly/monthly ZFS scrubbing it can detect silent data/disk corruption automatically and fix it. With a lot of data, that might get pretty important.. > Oh, and one more thing.. if you're going to use that many JBODs, pay attention to SES chassis management chips/drivers and software, so that you get the error/fault LEDs working on disk failure! -- Pasi