Rudi Ahlers wrote: > On Wed, Oct 20, 2010 at 4:34 AM, Nataraj <incoming-centos at rjl.com> wrote: > >> When I create my Raid arrays, I always use the option --bitmap=internal. >> With this option set, a bitmap is used to keep track of which pages on >> the drive are out of date and then you only resync pages which need >> updating instead of recopying the whole drive when this happens. In the >> past I once added a bitmap to an existing raid1 array using something >> like this. This may not be the exact command, but I know it can be done: >> mdadm /dev/mdN --bitmap=internal >> >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> http://lists.centos.org/mailman/listinfo/centos >> >> > > > > How do you add --bitmap=internal to an existing, running RAID set? I > have tried with the command above but got the following error: > > try mdadm /dev/md2 -Gb internal also it pays to have everything clean first and check you have a persistent superblock i.e. mdadm -D /dev/md2 HTH > [root at intranet ~]# mdadm /dev/md2 --bitmap=internal > mdadm: -b cannot have any extra immediately after it, sorry. > [root at intranet ~]# cat /proc/mdstat > Personalities : [raid1] > md0 : active raid1 hda1[0] > 104320 blocks [2/1] [U_] > > md2 : active raid1 sda1[0] sdb1[1] > 244195904 blocks [2/2] [UU] > > md1 : active raid1 hda2[0] > 244091520 blocks [2/1] [U_] > > > > > -------------- next part -------------- A non-text attachment was scrubbed... Name: rkampen.vcf Type: text/x-vcard Size: 278 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20101020/6cd94e55/attachment-0005.vcf>