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/linux
is a symbolic link to/usr/src/linux/include/linux
. Make sure that the new filesraid5.c
, etc. have been copied to their correct locations. Sometimes the patch command will not create new files. Try the-f
flag onpatch
.
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
A: Usemkraid
to initialize the RAID set prior to the first use.mkraid
ensures that the RAID array is initially in a consistent state by erasing the RAID partitions. In addition,mkraid
will create the RAID superblocks.
mdrun -a /dev/md0: Invalid argument
The setup was:
cat /proc/mdstat
shows
Personalities : read_ahead not set md0 : inactive sda1 sdb1 6313482 blocks md1 : inactive md2 : inactive md3 : inactive
A: Trylsmod
to see if the modules is loaded, and if not, load it withmodprobe raid1
.
On my Linux 2.0.30 system, while doing amkraid
for 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.
mdrun
a RAID-1, RAID-4 or RAID-5 device.
If I try to mdrun
a mdadd
'ed device I get
the message ''invalid raid superblock magic
''.
A:
Make sure that you've run the mkraid
part 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/md0
where x is l for linear, 0 for
RAID-0 or 1 for RAID-1, etc.
cat /proc/mdstat
shows
the total size of the device, but df only shows the size of the first
physical device.
A:
You must mkfs
your new md-dev before using it
the first time, so that the filesystem will cover the whole device.
/etc/mdtab
using mdcreate, I've
mdadd
'ed, mdrun
and fsck
'ed
my two /dev/mdX
partitions. Everything looks
okay before a reboot. As soon as I reboot, I get an
fsck
error 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 befsck
'ed. This must be done in one of the boot scripts. For some distributions,fsck
is called from/etc/rc.d/rc.S
, for others, it is called from/etc/rc.d/rc.sysinit
. Change this file tomdadd -ar
*before*fsck -A
is executed. Better yet, it is suggested thatckraid
be run ifmdadd
returns with an error. How do do this is discussed in greater detail in question 14 of the section ''Error Recovery''.
invalid raid superblock magic
while
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 2097175
while trying to run mke2fs on
a partition which is larger than 2GB.
A: This seems to be a problem withmke2fs
(November 97). A temporary work-around is to get the mke2fs code, and add#undef HAVE_LLSEEK
toe2fsprogs-1.10/lib/ext2fs/llseek.c
just before the first#ifdef HAVE_LLSEEK
and recompile mke2fs.
ckraid
currently isn't able to read /etc/mdtab
A: The RAID0/linear configuration file format used in/etc/mdtab
is obsolete, although it will be supported for a while more. The current, up-to-date config files are currently named/etc/raid1.conf
, etc.
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/md0
and get the message:
/dev/md0: Invalid argument
A: The default configuration for software RAID is 8 real devices. Editlinux/md.h
, change#define MAX_REAL=8
to a larger number, and rebuild the kernel.
md
work 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
ext2fs
will 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.