A: As of 18 Sept 1997, it is "2.0.30 + pre-9 2.0.31 + Werner Fink's swapping patch + the alpha RAID patch". As of November 1997, it is 2.0.31 + ... !?
A: Make sure that
/usr/include/linuxis a symbolic link to
/usr/src/linux/include/linux. Make sure that the new files
raid5.c, etc. have been copied to their correct locations. Sometimes the patch command will not create new files. Try the
A: raidtools-0.42 requires linuxthreads-0.6 from: ftp://ftp.inria.fr/INRIA/Projects/cristal/Xavier.Leroy Alternately, use glibc v2.0.
mdrun -a /dev/md0: Invalid argument
mkraidto initialize the RAID set prior to the first use.
mkraidensures that the RAID array is initially in a consistent state by erasing the RAID partitions. In addition,
mkraidwill create the RAID superblocks.
mdrun -a /dev/md0: Invalid argumentThe setup was:
Personalities : read_ahead not set md0 : inactive sda1 sdb1 6313482 blocks md1 : inactive md2 : inactive md3 : inactive
mdrun -agenerates the error message
/dev/md0: Invalid argument
cat /proc/modules) to see if the raid modules are loaded. If they are not, you can load them explicitly with the
modprobe raid5command. Alternately, if you are using the autoloader, and expected
kerneldto load them and it didn't this is probably because your loader is missing the info to load the modules. Edit
/etc/conf.modulesand add the following lines:alias md-personality-3 raid1 alias md-personality-4 raid5
mdadd -aI get the error:
/dev/md0: No such file or directory. Indeed, there seems to be no
/dev/md0anywhere. Now what do I do?
A: The raid-tools package will create these devices when you run
make installas root. Alternately, you can do the following:cd /dev ./MAKEDEV md
/dev/md0, I try to mount it and get the following error:
mount: wrong fs type, bad option, bad superblock on /dev/md0, or too many mounted file systems. What's wrong?
A: You need to create a file system on
/dev/md0before you can mount it. Use
On my Linux 2.0.30 system, while doing a
mkraidfor a RAID-1 device, during the clearing of the two individual partitions, I got
"Cannot allocate free page"errors appearing on the console, and
"Unable to handle kernel paging request at virtual address ..."errors in the system log. At this time, the system became quite unusable, but it appears to recover after a while. The operation appears to have completed with no other errors, and I am successfully using my RAID-1 device. The errors are disconcerting though. Any ideas?
A: This was a well-known bug in the 2.0.30 kernels. It is fixed in the 2.0.31 kernel; alternately, fall back to 2.0.29.
mdruna RAID-1, RAID-4 or RAID-5 device. If I try to
mdadd'ed device I get the message ''
invalid raid superblock magic''.
A: Make sure that you've run the
mkraidpart of the install procedure.
/dev/md0, the kernel spits out a lot of errors like
md0: device not running, giving up !and
I/O error.... I've successfully added my devices to the virtual device.
A: To be usable, the device must be running. Use
mdrun -px /dev/md0where x is l for linear, 0 for RAID-0 or 1 for RAID-1, etc.
cat /proc/mdstatshows the total size of the device, but
dfonly shows the size of the first physical device.
A: You must
mkfsyour new md-dev before using it the first time, so that the filesystem will cover the whole device.
/etc/mdtabusing mdcreate, I've
fsck'ed my two
/dev/mdXpartitions. Everything looks okay before a reboot. As soon as I reboot, I get an
fsckerror on both partitions:
fsck.ext2: Attempt to read block from filesystem resulted in short read while trying too open /dev/md0. Why?! How do I fix it?!
A: During the boot process, the RAID partitions must be started before they can be
fsck'ed. This must be done in one of the boot scripts. For some distributions,
fsckis called from
/etc/rc.d/rc.S, for others, it is called from
/etc/rc.d/rc.sysinit. Change this file to
fsck -Ais executed. Better yet, it is suggested that
ckraidbe run if
mdaddreturns with an error. How do do this is discussed in greater detail in question 14 of the section ''Error Recovery''.
invalid raid superblock magicwhile trying to run an array which consists of partitions which are bigger than 4GB.
A: This bug is now fixed. (September 97) Make sure you have the latest raid code.
Warning: could not write 8 blocks in inode table starting at 2097175while trying to run mke2fs on a partition which is larger than 2GB.
A: This seems to be a problem with
mke2fs(November 97). A temporary work-around is to get the mke2fs code, and add
e2fsprogs-1.10/lib/ext2fs/llseek.cjust before the first
#ifdef HAVE_LLSEEKand recompile mke2fs.
ckraidcurrently isn't able to read
A: The RAID0/linear configuration file format used in
/etc/mdtabis obsolete, although it will be supported for a while more. The current, up-to-date config files are currently named
raid1.o) are not loaded automatically; they have to be manually modprobe'd before mdrun. How can this be fixed?
A: To autoload the modules, we can add the following to
/etc/conf.modules:alias md-personality-3 raid1 alias md-personality-4 raid5
mdadd'ed 13 devices, and now I'm trying to
mdrun -p5 /dev/md0and get the message:
/dev/md0: Invalid argument
A: The default configuration for software RAID is 8 real devices. Edit
#define MAX_REAL=8to a larger number, and rebuild the kernel.
mdwork with partitions on our latest SPARCstation 5. I suspect that this has something to do with disk-labels.
A: Sun disk-labels sit in the first 1K of a partition. For RAID-1, the Sun disk-label is not an issue since
ext2fswill skip the label on every mirror. For other raid levels (0, linear and 4/5), this appears to be a problem; it has not yet (Dec 97) been addressed.