[CentOS] really large file systems with centos

[Pasi Kärkkäinen]

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..

-- Pasi