On 08/16/11 13:19, Iwan Zarembo wrote: > Hello Everyone, > I am not that new to Linux, but I am quite far away from being an > expert :) I am using linux for a few years now and everything worked > just fine, but not this one with IMSM Raid. I googled for some weeks > and asked everyone I know about the problem but without any luck. The > last possibility to find a solution is this mailing list. I realy hope > someone can help me. > I've just gone through this myself. (snip) > > I started the raid by entering the command: > # mdadm -I -e imsm /dev/md127 > mdadm: Started /dev/md/raid with 4 devices > > Now mdstat has the following output: > # cat /proc/mdstat > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] > [raid4] [raid10] > md126 : active (read-only) raid5 sdd[3] sdc[2] sdb[1] sde[0] > 2930280448 blocks super external:/md127/0 level 5, 128k chunk, > algorithm 0 [4/4] [UUUU] > resync=PENDING > > md127 : inactive sde[3](S) sdb[2](S) sdc[1](S) sdd[0](S) > 9028 blocks super external:imsm > > unused devices: <none> > What you are seeing here is the imsm container (/dev/md127), which you generally don't use unless you are trying to reconfigure arrays. The other device (/dev/md126) is the actual raid5 array as defined in the imsm BIOS. This is what you use in disk operations. Examples: $ parted /dev/md126 Then create partitions on the device - you'll have to use something compatible with gpt tables. When you do this, you'll have new devices available to you, such as /dev/md126p1 (first partition), /dev/md126p2 (second partition), and so on. However, if all you're doing is creating one big partition, you don't necessarily need a partition table, you can create a filesystem right on the array itself (/dev/md126) as I did on my server. > I learned that md126 is so long read only until it was used the first > time. So I tried to create a partition with the documentation from the > wiki, but not with ext3. I used ext4 for this. > > # mkfs.ext4 -v -m .1 -b 4096 -E stride=32,stripe-width=64 /dev/md/raid > The result was: > mke2fs 1.41.14 (22-Dec-2010) > fs_types für mke2fs.conf Lösung: 'ext4' > /dev/md/raid: The operation is not allowed then creating Superblocks. > Original message in German: Die Operation ist nicht erlaubt beim > Erstellen des Superblocks > > This is the first problem. I am not able to do anything on the raid drive. > Try using: `mkfs.ext4 -v -m .1 -b 4096 -E stride=32,stripe-width=64 /dev/md126` This, of course, assumes you aren't using a partition table. Substitute the correct partition device should you create one. > The second problem is that the raid is gone after the reboot! I'm not familiar with ubuntu, but you likely need to add a service to the startup scripts in order to start the raid array and have it usable, assuming that this is not the root device and is just being used for storage. It may need kernel arguments to tell mdadm to find and assemble arrays. Hopefully someone with Ubuntu experience can answer this. I know on my distribution (not Ubuntu!) I have to add a service to the boot runlevel in order to assemble arrays that are not the root filesystem. Dan -- 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
