On Mon, 27 Dec 2010 16:18:08 +0100 Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi everybody, > > I've been struggling with a software RAID issue for several days now. Before > sending the computer back to the vendor and asking for real RAID support, I'd > like to try my luck here. By "real RAID" I assume you mean "proprietary closed-source raid that is sold to you in an ROM" :-) > > The system as an Intel Matrix Storage SATA controller and two 250GB disks on > which I want to use a RAID1. > > I've been able to create the array properly from a Gentoo installation CD > (this might be a detail, but it might also influence homehost values, so I > thought I'd mention it) with the metadata stored in IMSM format. > > Assembling the array automatically from the installation CD works. > > livecd ~ # mdadm --assemble --scan > mdadm: Container /dev/md/imsm0 has been assembled with 2 drives > mdadm: Started /dev/md/vol0_0 with 2 devices > > livecd ~ # cat /proc/mdstat > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] > md126 : active (auto-read-only) raid1 sda[1] sdb[0] > 244195328 blocks super external:/md127/0 [2/2] [UU] > > md127 : inactive sdb[1](S) sda[0](S) > 4514 blocks super external:imsm > > unused devices: <none> > > livecd ~ # cat /proc/partitions > major minor #blocks name > > 7 0 94664 loop0 > 8 0 244198584 sda > 8 16 244198584 sdb > 8 32 998400 sdc > 8 33 998368 sdc1 > 9 126 244195328 md126 > 259 0 5242882 md126p1 > 259 1 5242884 md126p2 > 259 2 233709560 md126p3 > > So far, so good. > > I've then created an mdadm.conf file with mdadm -E --scan > > livecd ~ # mdadm -E --scan > ARRAY metadata=imsm UUID=480da1d0:8150f280:7dd8425d:bec99c46 > ARRAY /dev/md/vol0 container=480da1d0:8150f280:7dd8425d:bec99c46 member=0 > UUID=17e28225:34f7c425:eb78aece:05c29a40 > > livecd ~ # mdadm --assemble --scan > mdadm: Container /dev/md/imsm0 has been assembled with 2 drives > mdadm: Started /dev/md/vol0 with 2 devices > > livecd ~ # cat /proc/mdstat > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] > md126 : active (auto-read-only) raid1 sda[1] sdb[0] > 244195328 blocks super external:/md127/0 [2/2] [UU] > > md127 : inactive sdb[1](S) sda[0](S) > 4514 blocks super external:imsm > > unused devices: <none> > > livecd ~ # cat /proc/partitions > major minor #blocks name > > 7 0 94664 loop0 > 8 0 244198584 sda > 8 16 244198584 sdb > 8 32 998400 sdc > 8 33 998368 sdc1 > 9 126 244195328 md126 > 259 0 5242882 md126p1 > 259 1 5242884 md126p2 > 259 2 233709560 md126p3 > > Still good so far. The /dev/md/vol0_0 device is now called /dev/md/vol0. > > Copying the mdadm.conf file to initramfs and rebooting, the array is correctly > assemble with mdadm --assemble --scan > > livecd ~ # mdadm --assemble --scan > mdadm: Container /dev/md/imsm0 has been assembled with 2 drives > mdadm: Started /dev/md/vol0 with 2 devices > > livecd ~ # cat /proc/mdstat > Personalities : [raid1] > md126 : active (read-only) raid1 sda[1] sdb[0] > 244195328 blocks super external:/md127/0 [2/2] [UU] > > md127 : inactive sdb[1](S) sda[0](S) > 4514 blocks super external:imsm > > unused devices: <none> > > However, no partitions are detected. > > livecd ~ # cat /proc/partitions > major minor #blocks name > > 8 0 244198584 sda > 8 16 244198584 sdb > 8 32 998400 sdc > 8 33 998368 sdc1 > 9 126 244195328 md126 > > If I remove the /etc/mdadm.conf file from the initramfs image, the volume is > detected as vol0_0 instead of vol0 and the partitions are correctly detected. > > I don't understand what's going on there, and how I could fix it. Help would > be greatly appreciated. > That is very strange.... It might help if you could provide the complete boot logs so I can see everything that happened leading up to the partitions not being there. It would help me see if they were never created, or created then removed. The command blockdev --rereadpt /dev/md/vol0 should re-detect the partitions for you, so you could try doing something with that as a temporary fix. mdadm does sometime remove partitions, but only on things that it is about to include in an array, so it shouldn't ever remove the partitions on /dev/md/vol0. So something odd is happening, and more logs are needed to guess what. NeilBrown -- 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
