On Friday 11 November 2005 11:57, Erik Karlin wrote: > On Thu, Oct 27, 2005 at 01:13:39PM -0400, Steve Adeff wrote: > > On Thursday 27 October 2005 12:42, Erik Karlin wrote: > > > On Thu, Oct 27, 2005 at 05:07:50PM +0100, Alexander Fisher wrote: > > > > On 10/27/05, David Bennett <[EMAIL PROTECTED]> wrote: > > > > > I must admit you have me quite intrigued by this RAID 5. > > > > > > > > > > So heres the deal, I am going to go out and buy some disks. > > > > > Anything I need to know before I start? > > > > > > > > 250GB disks currently seem to give the most GB per $ or ? > > > > > > > > > How (and what) do I need to know to setup a software Raid 5 on my > > > > > linux? Any guides etc.? > > > > > > > > I've had quite a bit of success installing Debian with RAID and LVM > > > > configured during the install. GRUB won't boot off RAID5 (or LVM?) > > > > but it will boot off RAID1. Therefore, I would suggest something > > > > like this ... > > > > > > > > 3 disks sda,sdb,sdc. 3 partitions on each. > > > > sd[abc]1 small (<1GB) RAID 1 (md0) formatted ext3 and used for /boot. > > > > sd[abc]2 small formatted for swap. Swap is automatically striped > > > > across swap partitions. If you don't want your system to potentially > > > > crash when you have a disk failure, you can put swap over RAID 1 > > > > instead. > > > > > > I've done exactly this, though I did do a raid1 for swap too. > > > > > > > sd[abc]3 remaining space, RAID 5, and one LVM PV on top of this. > > > > Create one VG and several LVs out of this, one for each of your other > > > > filesystems (/, /usr /var/mediastore etc.) Format these XFS but > > > > don't make them bigger than they need to be, (XFS can easily grow > > > > filesystems online but doesn't support shrinking). > > > > > > Here's where I diverge, and haven't seen mentioned yet. I went the > > > raid10 route instead. with raid5, you can lose up to 1 drive in the > > > array. any more and you lose the array. With raid10 you can lose half, > > > in theory, as long as they're not in the same raid1 set. I've got > > > 6x250g disks as 3 raid1 mirrors and then raid0 the 3 raid1 arrays. > > > > does raid10 do parity? I thought raid 10 required a backup harddrive for > > every drive in the array? > > No, there is no parity in a raid 10 array. The resilence comes from the > raid1 parts(mirrors). Yes, it does require drives added in pairs, but > drives are relatively cheap. You can add raid1 arrays in degraded mode, > so in theory, you can create a raid10 array with only half the drives. I > used this to create my array with only 4 disks while I waited for the > drives to go on sale again. It's riskier, but there seem to be > "give-away" sales every couple of months. > > (Sorry it took so long to reply, it ended up in my spam folder)
ah, thats how you got away with less drives! thanks for clearing that up, Steve _______________________________________________ mythtv-users mailing list [email protected] http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
