Hi Shain, Am 20.01.2012 03:54, schrieb Shain Miley: > Hello all, > I have been doing some research into possible alternatives to our > OpenSolaris/ZFS/Gluster file server. The main reason behind this is, > due to RedHat's recent purchase of Gluster, our current configuration > will no longer be supported and even before the acquisition, the upgrade > path for the OpenSolaris/ZFS stack was murky at best. > > The current servers in question consist of a total of 48, 2TB drives. > My thought was that I would setup a total of 6 RAID-6 arrays (each > containing 7 drives + a spare or a flat 8 drive RAID-6 config) and place > LVM + XFS on top of that. > > My questions really are: > > a) What is the maximum number of drives typically seen in a RAID-6 > setup like this? I noticed when looking at the Backblaze blog, that > they are using RAID-6 with 15 disks (13 + 2 for parity). That number seemed > kind of high to me....but I was wondering what others on the list thought. > Typically RAID6 Arrays are most optimized with 2^n+2 drives, as in that case the stripe-size * data-disks adds up to a "good" big-block-size of a power of 2. A rule of thumb is to have one redundancy for any 4 disks. That makes a 6-drive RAID6 over-redundant and a 10-drive RAID6 "best to do". Next would be an 18-drive RAID6 - which compromizes the redundancy-rule big time. So I'd go for a 40-drive RAID60 and see what to do with the rest of the drives... > b) Would you recommend using any specific Linux distro over any other? > Right now I am trying to decide between Debian and Ubuntu....but I would be open to > any others...if there was a legitimate reason to do so (performance, stability, etc) in terms of the Raid codebase. This question isn't easy to answer - it depends on your needs. For storage systems I typically recommend open-e (www.open-e.com), because that's what we sell most (see www.exomium.com). It's also most stable as open-e does heavy QA on kernel and features. > > Thanks in advance, > > Shain > Hope this was helpful, Stefan > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
