Strange problem with Device Mapper

Strange problem with Device Mapper

[Paul Rolland]

Hello,

I've a machine that has been installed with Intel Soft Raid on top
of 2 SATA disks.
I'm trying to have this work as a RAID-1 array. 
Bios configuration has been done, using 128K chunk, and the kernel
(2.6.20.7) sees perfectly /dev/mapper/isw_xxxxxxxx_RAID1

But, I'm facing two problems :
1 - If i try to create partitions on this device, it does fail (the 
    values are not interpreted correctly)

2 - To avoid 1), I stop the RAID array (dmraid -an), then I do create
    exactly the same partition set on /dev/sda, and /dev/sdb, and
    then I reactivate RAID (dmraid -ay).
    This allows me to see all the /dev/mapper/isw_xxxxxxx_RAID1p1, p2, ...
    But, running fsck -t ext2 /dev/mapper/isw_xxxxxxx_RAID1p1
    ends in a lock when the partition is larger than 10Go (well, it is
    Ok on the 10Go one, and it locks on the 100Go).
    Not a real hardlock, I still can switch to a new VC, but it's not
    more possible to start a new command or to stop fsck.

Should I do everything on the physical disks before activating RAID ?
Is it a normal behavior ?

BTW, I also noticed that such a device doesn't support BLKRRPART ioctl...
So it is possible that what I'm doing is wrong...

Any idea ?

Regards,
Paul

Re: Strange problem with Device Mapper

[Andrew Morton]

On Thu, 26 Apr 2007 19:12:27 +0200 "Paul Rolland" <rol@as2917.net> wrote:

> Hello,
> 
> I've a machine that has been installed with Intel Soft Raid on top
> of 2 SATA disks.
> I'm trying to have this work as a RAID-1 array. 
> Bios configuration has been done, using 128K chunk, and the kernel
> (2.6.20.7) sees perfectly /dev/mapper/isw_xxxxxxxx_RAID1
> 
> But, I'm facing two problems :
> 1 - If i try to create partitions on this device, it does fail (the 
>     values are not interpreted correctly)
> 
> 2 - To avoid 1), I stop the RAID array (dmraid -an), then I do create
>     exactly the same partition set on /dev/sda, and /dev/sdb, and
>     then I reactivate RAID (dmraid -ay).
>     This allows me to see all the /dev/mapper/isw_xxxxxxx_RAID1p1, p2, ...
>     But, running fsck -t ext2 /dev/mapper/isw_xxxxxxx_RAID1p1
>     ends in a lock when the partition is larger than 10Go (well, it is
>     Ok on the 10Go one, and it locks on the 100Go).
>     Not a real hardlock, I still can switch to a new VC, but it's not
>     more possible to start a new command or to stop fsck.
> 
> Should I do everything on the physical disks before activating RAID ?
> Is it a normal behavior ?
> 
> BTW, I also noticed that such a device doesn't support BLKRRPART ioctl...
> So it is possible that what I'm doing is wrong...
> 
> Any idea ?
> 

cc added.