--- On Wed, 13/4/11, John Robinson <john.robinson@xxxxxxxxxxxxxxxx> wrote: > From: John Robinson <john.robinson@xxxxxxxxxxxxxxxx> > Subject: Re: RAID6 data-check took almost 2 hours, clicking sounds, system unresponsive > To: "NeilBrown" <neilb@xxxxxxx> > Cc: "Gavin Flower" <gavinflower@xxxxxxxxx>, linux-raid@xxxxxxxxxxxxxxx > Date: Wednesday, 13 April, 2011, 23:58 > On 13/04/2011 12:13, NeilBrown > wrote: > > On Wed, 13 Apr 2011 11:57:24 +0100 John Robinson > > <john.robinson@xxxxxxxxxxxxxxxx> > wrote: > >> On 12/04/2011 22:30, Gavin Flower wrote: > [...] > >>> md0 : active raid6 sda3[0] sdb3[4] sdd3[3] > sdc3[5](F) sde3[1] > >>> 10751808 > blocks level 6, 64k chunk, algorithm 2 [5/4] [UU_UU] > >> > >> This one I don't get: > >> md0 : active raid6 sda3[0] sde3[1] sdd3[3] sdb3[4] > sdc3[5](F) > >> which ought to be UUUU_ again... > >> > >> Perhaps `mdadm -D /dev/md[0-2]` would make things > clearer... > > > > This is actually more horrible than you imagine. > > It isn't really, I was asking for the mdadm -D output > precisely to get the list of role and slot numbers, having > noticed there was no slot 2 in Gavin's setup... > > [...] > > As the current number is pretty much useless, I should > probably change it to > > the slot number, or an arbitrarily assigned larger > number for spares. > > This would be an incompatible change, but I very much > doubt anyone uses the > > numbers for what they actually are, so I doubt that > would really matter. > > > > It has just never really got high on my list of > priorities.... > > > > Lesson: Ignore the number in [] - it doesn't > mean anything useful. > > It's not useless, it reflects the order in which devices > were added to the array. > > Suggestion: Don't change the number in /proc/mdstat, just > sort the devices by role (i.e. the same order as the UUUU_) > instead of device node, and show spares at the end (as per > your arbitrarily-assigned larger number, which this way you > never have to display). > > Cheers, > > John. > The first time I saw this kind of thing: I was very worried, thinking I had 2 bad drives - until I looked more closely, a few hours later. I am sure I am not the only to initially react that way. >From a user perspective, I think that the list of drives and the [UUUU_] string, should be ordered in the alphanumeric order of the logical drive names. Also modify the '[...]' string to indicate spares (not having spares, not sure what it does now). e.g. /dev/sda /dev/sdb /dev/sdc[F} /dev/sdd /dev/sde[S} /dev/sdf. would be reflected by: [aaFaSa] Not sure what the 'U' stood for. Marking actives disks with 'a' seems to make more sense to me. The upper and lower case would make it easier to see what is active and what is not. Similarly, the RAID entries would be better, from a user perspective, to be sorted on name. There are probably lots of technical reasons this can't be done, but users don't care! :-) We just want it to look pretty, be easy to understand, and not be scary. Just my 2 pennies worth... When I put my developer hat on, I tend to feel that users rate looking pretty' and 'not be scary' as being more important than 'be easy to understand' - or perhaps, I am too cynical -- 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
