On Tue, 2004-01-13 at 07:39, Arthur Moore wrote:
On Mon, 2004-01-12 at 17:54, Devlin Daley wrote: <snio>
I am really leaning toward using software RAID, so should I put the two drives on the same controller?
no they have to be on separate controllers I believe.
Software RAID on linux doesn't care at all about the controllers. You can easily RAID disks on one controller. You should, however, be aware of the performance implications. Most controllers support 2 IDE channels (2 cable buses). Basically each IDE channel can support 2 drives, but it can only access one drive at a time. Thus if you RAID across 2 disks on one channel, your performance will be quite bad as there will be a lot of bus contention. You can, however, RAID with good performance across 2 drives on separate channels. Most controllers support 2 channels, so you can put one drive on each channel without any problems. If you stripe the disk, both read and writes should speed up. If you mirror the disks, then writes will be about the same, but reads should be faster. So you really only need your one promise controller.
Let's take it a step further: Linux sofware RAID doesn't care at all about disks. You can just as easily make a couple of partitions on a single disk and RAID those partitions. You wouldn't want to, of course, but you can.
Is it even possible to RAID the raw disk? Don't you need to have partitions on them?
____________________
BYU Unix Users Group http://uug.byu.edu/ ___________________________________________________________________
List Info: http://uug.byu.edu/cgi-bin/mailman/listinfo/uug-list
