Personal computing discussed
Moderators: renee, SecretSquirrel, notfred
just brew it! wrote:Decided not to get really adventurous and use software RAID-1 for the boot volume, eh?
SuperSpy wrote:Which distro did you end up using?
flip-mode wrote:I set the array up on Ubuntu. But then for fun I copied my mdadm.conf to a usb drive then yanked Ubuntu and did a clean install of Debian 6.01a. After install, I just copied my mdadm.conf from the usb drive and rebooted and the array started up without a single issue. That's pretty frickin awesome. That's the beauty of Linux and conf files, and for whatever reason it continues to impress me. The learn can be a steep climb at times, but after that things can be done and then replicated with amazing speed.
flip-mode wrote:Oh, by the way, I wanted to ask opinions on whether to go RAID1 or RAID5 for the office file server.
If I do RAID5, it would be with (3) 1TB drives.
If I do RAID1, it would be with (2) 2TB drives.
Fault tolerance is the same, although the likelihood of a drive failure is 50% higher with 3 drives instead of 2. Performance of RAID5 is better than RAID1 according to the md manual, but I'm not so sure the performance differences will be dramatic enough to matter. Power consumption isn't really worth factoring in.
So, I'm leaning RAID1, but want to hear you all's thoughts.
DancinJack wrote:My vote is for RAID1. You can easily backup R1 while keeping one of the drives active too. Near 24/7 operation.
just brew it! wrote:I believe with the RAID-5 you have the option of adding a drive and "reshaping" the array in place to add capacity in the future.
just brew it! wrote:DancinJack wrote:My vote is for RAID1. You can easily backup R1 while keeping one of the drives active too. Near 24/7 operation.
Another interesting option for doing backups is to use LVM to set up a "snapshot" file system. This ensures a consistent point-in-time backup image, with essentially zero downtime.
axeman wrote:And this is due to performance or what?Don't run RAID5 in software. Even with a dedicated RAID controller than can do all the parity calculations, the consensus seems to be that RAID 10 is a better solution overall except when it comes to how much disk space is used by the redundancy, which is a non-issue given the price/GB that disks are at these days.
flip-mode wrote:axeman wrote:And this is due to performance or what?Don't run RAID5 in software. Even with a dedicated RAID controller than can do all the parity calculations, the consensus seems to be that RAID 10 is a better solution overall except when it comes to how much disk space is used by the redundancy, which is a non-issue given the price/GB that disks are at these days.
just brew it! wrote:Another interesting option for doing backups is to use LVM to set up a "snapshot" file system. This ensures a consistent point-in-time backup image, with essentially zero downtime.
md2 : active raid5 sda4[0] sdd4[4] sdb4[2] sdc4[1]
2843822592 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
md1 : active raid10 sda2[0] sdd2[4] sdb2[2] sdc2[1]
48825344 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
md0 : active raid1 sda1[0] sdd1[4] sdb1[2] sdc1[1]
498676 blocks super 1.2 [4/4] [UUUU]
notfred wrote:That first link is rather old, it's before the advent of SMART and block remapping in IDE drives. I agree with the performance penalty parts, but the bit about drives quietly dying is now invalid.
flip-mode wrote:Fault tolerance is the same, although the likelihood of a drive failure is 50% higher with 3 drives instead of 2. Performance of RAID5 is better than RAID1 according to the md manual, but I'm not so sure the performance differences will be dramatic enough to matter. Power consumption isn't really worth factoring in.
So, I'm leaning RAID1, but want to hear you all's thoughts.