I have a few questions about my raid array that I haven't been able to find definitive answers for, so thought I would ask here. My setup: * 8x 1TB drives in an external enclosure connected to my server via 2 esata cables. * Currently all 8 drives are included in a raid 6 array. * I use the array to serve files (mostly larger .mkv/iso (several GB) and .flac/.mp3 (5-50MB) files) over my network via NFS and to perform offsite backup via rsync over ssh of another server. * This is a system in my home, so prolonged downtime, while annoying, is not the end of the world. * If it matters Ubuntu 10.04 64bit server is my distro I'm considering and likely going to move forward moving my data and rebuilding the array as a raid10 array. Just a few questions before I make the switch. Questions: 1. In my research of raid10 I very seldom hear of drive configurations with more drives then 4, are there special considerations with having an 8 drive raid10 array? I understand that I'll be loosing 2TB of space from my current setup, but i'm not too worried about that. 2. One problem I'm having with my current setup is the esata cables have been knocked loose which effectively drops 4 of my drives. I'd really like to be able to survive this type of sudden drive loss. if my drives are /dev/sd[abcdefgh] and abcd are on one esata channel while efgh are on the other is there what drive order should I create the array with? I'd guess /dev/sd[aebfcgdh] would that give me survivability if one of my esata channels went dark? 3. One of the concerns I have with raid10 is expandability, and I'm glad to see reshaping raid10 as an item on the 2011 roadmap :) However it will likely be a while before I'll see that ability in my distro for a while. I did find a guide on expanding raid size when using lvm by increasing the size of each drive and creating two partitions 1 the size of the original drive, and one with the remainder of the new space. Once you have done this for all drives you create a new raid10 array with the 2nd partitions on all the drives and add it to the lvm storage group, effectively you have two raid10 arrays 1 on the first half of the drives 1 on the 2nd half of the drives and the space pooled together. I'm sure many of you are familiar with this scenario, but I'm wondering if this scenario could be problematic, is having two raid10 arrays on one drive an issue? 4. Part of the reason I'm wanting to switch is because of information I read on the "BAARF" site pointing out some of the issues in the parity raid's that can cause issues that people sometimes don't think about. (site: http://www.miracleas.com/BAARF/BAARF2.html) A lot of the information on the site is a few years old now and given how fast things can change and the fact that I have not found many people complaining about the parity raids I'm wondering if some/all of the gotchas that they list are less of an issue now? Maybe my reasons for moving to raid10 are no longer relevant? Thank you in advance for any/all information given. And a big thank you to Neil and the other developers of linux-raid for their efforts on this great tool. Larry Schwerzler -- 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
