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Newbie needs RAID help!
I tried not to post, really I did. I read the Software RAID HOW-TO and a bunch of posts, but I can't get it to work:
Running RH9, with all OS already running on /dev/hda Have 2 new HDs, /dev/hde & /dev/hdg with which I want to create a RAID 1 array. The new array will not have any OS stuff, it will stay on /dev/hda. Partitioned the drives using fdisk: used n to create the new partition using all available space used t to change the partition ID to RAID auto (fd) When I use the Hardware Browser I see the two drives, and the partition type is shown as 'software RAID component' Created a /etc/raidtab as shown in the HOW-TO Now I am confused as to what comes next. I tried mkraid /dev/md0 which gives the response: handling MD device /dev/md0 analyzing super-block invalid chunk-size (0kB) mkraid: aborted. I don't know where to go from here. Did I do the fdisk wrong, or have I missed a step??? Help! Thanks, Frank |
you can try mkraid -f /dev/md0
make sure the /etc/raidtab file is correct |
try #man mkraid. You may have left out a switch as it says "invalid chunk-size (0kB)". Check for a switch on chunk size...
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Thanks for the suggestions, but it hasn't helped. I did add a line to /proc/readitab that said:
chunk-size 8 That made mkraid do something. (But in my kernal log, I then see a warning that a RAID1 array doesn't need a chunk-size. So, I took the line out to get rid of the warning.) But during boot, the system tells me that there is a problem with hde and hdg and it can't import them, so it doesn't use md0. (Sorry I'm not at that machine, so I don't have exact text) The filesystem I put on the drives is ext3. Should I have an ext2 filesystem to do RAID1? |
no ext3 should be ok
mkraid should recreate the raid partitions when you create md0 whats in the /etc/raidtab file does your kernel support RAID |
David, thanks for the assistance. Here is the contents of the /etc/raidtab file:
raiddev /dev/md0 raid-level 1 nr-raid-disks 2 persistent-superblock 1 device /dev/hde1 raid-disk 0 device /dev/hdg1 raid-disk 1 AFAIK the kernel supports RAID. It is RH9 and I can see from the kernel log that it is checking for auto RAID and other RAID things, so I assume all the support is there. Is there a way to check for sure? One other thing - these two drives are on a SIIG PCI controller. I believe it is being correctly identified and used (I can fdisk the drives, add a fs, etc). I can send the kernel log if that would be any help. Frank |
I guess you need to try this
lsraid -a /dev/md0 you should see something like this [dev 9, 0] /dev/md0 955E5224.08C9D222.1A09677B.BBCFE189 online [dev 3, 2] /dev/hda2 955E5224.08C9D222.1A09677B.BBCFE189 good [dev 3, 67] /dev/hdb3 955E5224.08C9D222.1A09677B.BBCFE189 good now if it looks ok then run this to update your /etc/raidtab file lsraid -R -a /dev/md0 > /etc/raidtab the output goes to /etc/raidtab and looks like this.. lsraid -R -a /dev/md0 # This raidtab was generated by lsraid version 0.7.0. # It was created from a query on the following devices: # /dev/md0 # md device [dev 9, 0] /dev/md0 queried online raiddev /dev/md0 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 persistent-superblock 1 chunk-size 64 device /dev/hda2 raid-disk 0 device /dev/hdb3 raid-disk 1 for someone with multiple devices use it like this lsraid -R -a /dev/md0 -a /dev/md1 # This raidtab was generated by lsraid version 0.7.0. # It was created from a query on the following devices: # /dev/md0 # /dev/md1 # md device [dev 9, 0] /dev/md0 queried online raiddev /dev/md0 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 persistent-superblock 1 chunk-size 64 device /dev/hda2 raid-disk 0 device /dev/hdb3 raid-disk 1 # md device [dev 9, 1] /dev/md1 queried online raiddev /dev/md1 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 persistent-superblock 1 chunk-size 64 device /dev/hda1 raid-disk 0 device /dev/hdb1 raid-disk 1 |
David,
Thanks again for the help. Seems like I found the lsraid command and used it but I don't remember what it did (or even where in the process I used it...) I'll give it a try tonight. It seems like when I used it, it told me that /dev/md0 was not online. And then I think I did a raidstart and tried it again and got an ok response. But at that point, the kernel still had a problem with - what would the term be, starting? - md0. But I'm not sure of that so I'll post again when I can try it again. Frank |
If the raid device is not there then try this
mdadm --create /dev/md0 --chunk=64 --level=raid1 --raid-devices=2 /dev/hde1 /dev/hdg1 mdadm --detail --scan >> /etc/mdadm.conf |
so if /dev/md0 was there then I would issue these commands..
mke2fs -j /dev/md0 mkdir /somewhere mount /dev/md0 /somewhere mount | grep md0 /dev/md0 on /somewhere type ext3 (rw) also maybe the array is still resyncing, try this to see.. cat /proc/mdstat |
Ok, I played around some more last night. I think the array is actually working. Here's what I did:
==================================================== [root@ServerPress root]# lsraid -a /dev/md0 lsraid: md device [dev 9, 0] /dev/md0 is offline: Please specify a disk to query [root@ServerPress root]# mdadm --create /dev/md0 --chunk=64 --level=raid1 --raid-devices=2 /dev/hde1 /dev/hdg1 bash: mdadm: command not found [root@ServerPress root]# /sbin/mdadm --create /dev/md0 --chunk=64 --level=raid1 --raid-devices=2 /dev/hde1 /dev/hdg1 bash: /sbin/mdadm: No such file or directory [root@ServerPress root]# man mdadm No manual entry for mdadm [root@ServerPress root]# cat /proc/mdstat Personalities : read_ahead not set unused devices: <none> [root@ServerPress root]# mkraid /dev/md0 handling MD device /dev/md0 analyzing super-block disk 0: /dev/hde1, 78148161kB, raid superblock at 78148096kB disk 1: /dev/hdg1, 78148161kB, raid superblock at 78148096kB [root@ServerPress root]# [root@ServerPress root]# lsraid -a /dev/md0 [dev 9, 0] /dev/md0 83EBB493.4B4C15DB.28AAF54B.EA0920B8 online [dev 33, 1] /dev/hde1 83EBB493.4B4C15DB.28AAF54B.EA0920B8 good [dev 34, 1] /dev/hdg1 83EBB493.4B4C15DB.28AAF54B.EA0920B8 good [root@ServerPress root]#lsraid -R -a /dev/md0 > /etc/raidtab # This raidtab was generated by lsraid version 0.7.0. # It was created from a query on the following devices: # /dev/md0 # md device [dev 9, 0] /dev/md0 queried online raiddev /dev/md0 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 persistent-superblock 1 chunk-size 64 device /dev/hde1 raid-disk 0 device /dev/hdg1 raid-disk 1 [root@ServerPress root]# mke2fs -j /dev/md0 mke2fs 1.32 (09-Nov-2002) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 9781248 inodes, 19537024 blocks 976851 blocks (5.00%) reserved for the super user First data block=0 597 block groups 32768 blocks per group, 32768 fragments per group 16384 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424 Writing inode tables: done Creating journal (8192 blocks): done Writing superblocks and filesystem accounting information: done ==================================================== As you can see, no mdadm program :,( Also, I did cat /proc/mdstat and finally realized that it was resyncing, and that that process would take a long time (don't know why, there were no files on the disks) Now after a reboot I get this: (this message shows on the screen but does not show in any log file I can find) Starting up RAID devices: md0(skipped) [root@ServerPress root]# cat /proc/mdstat Personalities : read_ahead not set unused devices: <none> [root@ServerPress root]# lsraid -a /dev/md0 lsraid: md device [dev 9, 0] /dev/md0 is offline: Please specify a disk to query[root@ServerPress root]# raidstart /dev/md0 [root@ServerPress root]# cat /proc/mdstat Personalities : [raid1] read_ahead 1024 sectors md0 : active raid1 hdg1[1] hde1[0] 78148096 blocks [2/2] [UU] unused devices: <none> [root@ServerPress root]# cat /proc/mdstat Personalities : [raid1] read_ahead 1024 sectors md0 : active raid1 hdg1[1] hde1[0] 78148096 blocks [2/2] [UU] unused devices: <none> [root@ServerPress root]# mount /dev/md0 /SharedDocs [root@ServerPress root]# ls /SharedDocs lost+found [root@ServerPress root]# So, it looks like the RAID isn't starting during boot, but can be started manually. Any ideas as to how to get it start automatically? (and then once that works then I just put the mount info in /etc/fstab right?) Thanks, Frank |
mdadm is not really necessary anyway, mkraid does basically the same thing except it requires a raidtab file, where all parameters are given with mdadm so no raidtab file is necessary to create the raid device.
I have this script in /etc/rc.d/rc.sysinit file, that's were your error is coming from... # Add raid devices if [ ! -f /proc/mdstat ]; then modprobe md >/dev/null 2>&1 fi if [ -f /proc/mdstat -a -f /etc/raidtab ]; then echo -n $"Starting up RAID devices: " rc=0 for i in `grep "^[^*]*raiddev" /etc/raidtab | awk '{print $2}'` do RAIDDEV=`basename $i` RAIDSTAT=`grep "^$RAIDDEV : active" /proc/mdstat` if [ -z "$RAIDSTAT" ]; then # First scan the /etc/fstab for the "noauto"-flag # for this device. If found, skip the initialization # for it to avoid dropping to a shell on errors. # If not, try raidstart...if that fails then # fall back to raidadd, raidrun. If that # also fails, then we drop to a shell RESULT=1 NOAUTO=`grep "^$i" /etc/fstab | grep -c "noauto"` if [ $NOAUTO -gt 0 ]; then RESULT=0 RAIDDEV="$RAIDDEV(skipped)" fi if [ $RESULT -gt 0 -a -x /sbin/raidstart ]; then /sbin/raidstart $i RESULT=$? fi if [ $RESULT -gt 0 -a -x /sbin/raid0run ]; then /sbin/raid0run $i RESULT=$? fi if [ $RESULT -gt 0 -a -x /sbin/raidadd -a -x /sbin/raidrun ]; then /sbin/raidadd $i /sbin/raidrun $i RESULT=$? fi if [ $RESULT -gt 0 ]; then rc=1 fi echo -n "$RAIDDEV " else echo -n "$RAIDDEV " fi done echo # A non-zero return means there were problems. if [ $rc -gt 0 ]; then echo echo echo $"*** An error occurred during the RAID startup" echo $"*** Dropping you to a shell; the system will reboot" echo $"*** when you leave the shell." PS1=$"(RAID Repair) \# # "; export PS1 sulogin echo $"Unmounting file systems" umount -a mount -n -o remount,ro / echo $"Automatic reboot in progress." reboot -f fi fi It looks like you just need to add the entry to /etc/fstab and it should work ok. |
That looks like that script will handle all types of RAID. I haven't done any scripts yet, so I can follow what you are doing but I'll have to look up all the command to see exactly what is going on.
Uh, is this PERL? Also, when I last did fdisk I did not set the RAID flag on either HD. If I set the flag, will the auto function start the RAID? Or what benefit is having the flag set? Thanks again for your help. I'll try this out tonight, and I think it will get me going. (Now, about the remote administration from a WinXP desktop....) Frank |
the kernel will autodetect it, it should be set.
you have the script already on RH9. if you set the raid audetect flag type fd and add the entry to /etc/fstab you shouldn't need to do anything else. |
David, Success! Many thanks :>)
Now that it is working, I have a couple of questions regarding use. In /etc/fstab I have the entry: /dev/md0 /SharedDocs ext3 rw 0 0 Previously I had: /dev/md0 /SharedDocs ext3 defaults 0 0 which did not seem to work. Should it? Would I need to define the defaults somewhere? Also, I want to make the /SharedDocs folder available to WinXP machines on the network. I have Samba running properly and have another folder (/tmp) shared. So I used the Samba config app to add /SharedDocs/Frank to the Samba shares, made it r/w, set it to only be available to frank. I can see this directory and read it from my XP machine when logged in as Frank. But I can't write it. Do I have to set permissions somewhere? Thanks so much for your time and patience! Frank |
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