Having had this happen to me a while back I can tell you.<br><br>Without any special configuration MDADM is pretty silent. Alot of distributions have some nightly e-mails going to root that might include mdadm information (typically a cat of /proc/mdstat), and I know there are some 3rd party tools that will monitor MDSTAT for you, but by and large you're pretty much on your own to my knowledge.
<br><br>Replacing a disk is pretty easy. Shutdown your system (unless you have hotpluggable drives, in which case you can send me $3000 for the advice here as I seem to need the money more than you do *GRIN*), and install a new disk onto the raid controller.
<br><br>When the system comes back up, MDADM should recognize the drive and add it as "spare", using a command (don't know off the top of my head, do a man on mdadm) you will add that drive into your raid array and it will automatically rebuild for you. Not hard stuff.
<br><br>--Douglas Wagner<br><br>p.s. I'm still a newbie to RAID6, given appropriate precautions though (don't buy the drives all at the same time from the same source that are the same model/run, etc.) it's unlikely that in 5+ disks you'll have two fail at one time...RAID5 is still what most business runs I think (at least the one I work for does).
<br><br><div><span class="gmail_quote">On 5/1/06, <b class="gmail_sendername">Dean Wilson</b> <<a href="mailto:dean.k.wilson@gmail.com">dean.k.wilson@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Thanks for your help!<br><br>> RAID 4 is similar to 5 except that it uses a dedicated disk for the<br>> parity information rather than striping it across all the other disks.<br><br>Is this good/bad/indifferent for Myth? Can I specify which disk gets
<br>the parity info? (If so, since I'm likely to have to have a single<br>PATA drive anyway (with the others being SATA), would it benefit me to<br>specify this drive as the parity disk?<br><br>> RAID 6 is basically RAID 5 but with two separate parity sets allowing
<br>> for failure of two drives (but with 2 drives worth of storage space<br>> lost).<br><br>Is this necessary? As I understand it, as long as I don't have a huge<br>array of disks, the likelyhood of more than two disks dying at the
<br>same time are low. So as long as I replace the disk ASAP, I should be<br>fine with only one parity disk, yes?<br><br>Speaking of replacing disks, how difficult is it to replace a bad disk<br>with mdadm? (And how will I know if a disk has gone bad? Will it
<br>limp along, or force me to replace it immediately?)<br><br>Again, thanks for all your help!<br>_______________________________________________<br>mythtv-users mailing list<br><a href="mailto:mythtv-users@mythtv.org">mythtv-users@mythtv.org
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