[coLinux-devel] Problem with raid5, hangs after reading a few bytes

[David R. <dr...@gm...>]

Hi,
I'm trying to use colinux to access linux software raid-5 partitions from
windows. I've got coliunx setup & running fine, and raid-1 works well, but
with raid-5 there is an odd problem. I can assemble the raid array, mount
the array, list files inside it, and even access very small files (not sure
exact size, but things like 1 or 2KB max). But as soon as I try to
open/copy/md5sum (just to test) a file that's a couple KB or larger, the
command hangs. Colinux is still running fine, there are no errors in the
console, it's just the command accessing the files is hung. I cannot even
kill the command (cp, md5sum, or whatever I used).

I saw there were some fixes for raid-5 in the very latest 0.7.4-rc2, which
is what I'm using now, and I have confirmed that it is NOT using mmx or sse
checksumming commands (from dmesg):

> md: raid1 personality registered for level 1

raid5: measuring checksumming speed

   8regs     :  4271.200 MB/sec

   8regs_prefetch:  4348.400 MB/sec

   32regs    :  2592.400 MB/sec

   32regs_prefetch:  2247.600 MB/sec

raid5: using function: 8regs_prefetch (4348.400 MB/sec)

raid6: int32x1    865 MB/s

raid6: int32x2    839 MB/s

raid6: int32x4    667 MB/s

raid6: int32x8    622 MB/s

raid6: using algorithm int32x1 (865 MB/s)


I'm using the Ubuntu-7.10.ext3.2gb root filesystem, and I'm using Xming to
access X11 apps.

Here's a snippet from my colinux.conf file, I'm using cobd to access drive
partitions directly. The colinux wiki is very confusing on this matter, with
some conflicting info, depending on which page you view, so it may be there
is a better way to access native partitions than
"cobd2=\Device\Harddisk1\Partition3" which I am using.

> # File contains the root file system.

# Download and extract preconfigured file from SF "Images for 2.6".

cobd0="Ubuntu-7.10.ext3.2gb.fs"


> # Swap device, should be an empty file with 128..512MB.

cobd1="swap128.fs"


> # large ext3 partition - works fine

cobd2=\Device\Harddisk1\Partition3


> # raid-5 - has mentioned problem

cobd3=\Device\Harddisk1\Partition1

cobd4=\Device\Harddisk2\Partition1

cobd5=\Device\Harddisk3\Partition1


> # raid-1 - works fine

#

cobd6=\Device\Harddisk1\Partition2

cobd7=\Device\Harddisk2\Partition2


Please let me know the best way to go about debugging this, if you would
like me to run the colinux debugging tool, or if there are other tests I can
run to try and solve this issue.

Thanks for the help, and thanks for colinux, it's really a wonderful idea.
-David R