> From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > owner@xxxxxxxxxxxxxxx] On Behalf Of Mitchell Laks > Sent: Friday, April 29, 2005 2:26 AM > To: linux-raid@xxxxxxxxxxxxxxx > Subject: what does spares=1 mean in mdadm --detail --scan for raid1 > > Hi, > I have multiple raid 1 devices on my system. > > recently i noticed read seek errors in /var/log/kern.log from /dev/hdi1 > which > is part of /dev/md1. > > I then did a lot of work with /dev/md1 and then i noticed that /dev/hdi1 > failed in the /dev/md1 but the data was fine on remaining part of raid1. > > I then shut system down and > then i put in another device to replace /dev/hdi1 and rebooted > > At this point of rebooting, i had forgotten to edit the contents > of /etc/mdadm/mdadm.conf and it still had the line something like > > ARRAY /dev/md1 level=raid1 num-devices=2 \ > UUID=d876333b:694e852b:e9a6f40f:0beb90f9 > devices /dev/hdc1,/dev/hdi1 > > then i got an error from fsck on bootup as it reached /dev/md1 > and dropped me into single user mode > then i changed the mdadm.conf file to > > ARRAY /dev/md1 level=raid1 num-devices=2 > UUID=d876333b:694e852b:e9a6f40f:0beb90f9 > devices /dev/hdc1 > > and it booted fine. This seems very wrong to me! I hope someone else can help here! > > i then did > mdadm /dev/md1 -a /dev/hdi1 > to add in my new drive. > > Mdadm then began to recreate the array. > > and then, while the raid was in the process of rebuilding > i did > mdadm --detail --scan > and the line read > > ARRAY /dev/md1 level=raid1 num-devices=2 spares=1 \ > UUID=d876333b:694e852b:e9a6f40f:0beb90f9 > devices /dev/hdc1,/dev/hdi1 > > so my question for the group is > > what is the meaning of spares=1? When you add a disk it is a spare. If needed, it is used to replace a missing disk. Once the re-sync is done it will not be a spare. > > does it mean to indicate that the device is still rebuilding? > > On the other raid 1 devices on my system, such as > /dev/md0 the mdadm --detail --scan says > > ARRAY /dev/md0 level=raid1 num-devices=2 > UUID=d876333b:694e852b:e9a6f40f:0beb90f9 > devices /dev/hda1,/dev/hdg1 > > without the spares=1 clause. > > The reason I ask is: What should I write into my new version of > mdadm.conf? > I am guessing I should write > > ARRAY /dev/md1 level=raid1 num-devices=2 > UUID=d876333b:694e852b:e9a6f40f:0beb90f9 > devices /dev/hdc1,/dev/hdi1 > > without the spares=1 thing. > > I am confused what spares=1 is for..... I am confused by the change you had to make! But you should not add "spares=1". > > Thanks!!! > Mitchell Laks Guy - 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
