Debian and vendor proprietary RAID

[András Imre]

On 4/14/06, Molle Bestefich <molle.bestefich at gmail.com> wrote:
> The only graphical installer I know of that supports dmraid is
> anaconda in Fedora Core 5.
>
> If FC5 uses standard Grub, then it might nuke your RAID array
> depending on the controller you use.  I know that Fedora Core 4 does
> that on my HighPoint controller.
>
> The Gentoo (text-based) installation system supports dmraid too.
> That system will however for sure destroy HighPoint (others? dunno!..) arrays.

My current target is Debian, but thanks for the tips - will try these
distros later.
I tried Ubuntu 5.10 Live CD just to see if it works. It failed.

> So even when you do find an installer that works, taking a backup of
> your metadata before you start is not an entirely bad idea.  I learned
> the hard way :-).

I do show respect when fiddling around with these tools. :)
This is a test environment, so nothing much to lose.
But thanks for warning.

> > dmraid version:         1.0.0.rc9 (2005.09.23)
> > dmraid library version: 1.0.0.rc9 (2005.09.23)
> > device-mapper version:  4.5.0
>
> You should upgrade dmraid to the latest version before posting bug reports.

rc10 is not available for me with aptitude. I had to compile and install
it manually. No problems. The outputs are the same, except
for the following 2 additional/1 changed lines for dmraid -ay -vvv -d:
...
device-mapper: dm-linear: Device lookup failed
device-mapper: error adding target to table
...
ERROR: dos: reading /dev/mapper/via_bdafghaihj[No such file or directory]
...

The second line also appears in syslog. Checked backwards, and found that
this appeared for rc9 also, just was not displayed on console. Not too much
difference, I guess.

>
> There's a dmraid<->devicemapper dependency, but it's not going to tell
> you if your devicemapper is too old.  Instead you'll get obscure
> warnings, but not on the console - only in /var/log/messages (or
> wherever your syslog points).  So beware of that when upgrading.

The second line from above appears in messages also. No other
relevant warnings found in files under /var/log/. Is there anything else
I should be looking for?

> > # dmraid -ay -vvv -d
> > ERROR: opening "/dev/mapper/via_bdafghaihj"
>
> This error is possibly because you've run dmraid -ay multiple times.
> For testing purposes, it's probably a good idea to disable existing
> dmraid devices with 'dmraid -an' before making debug output.

I did so, thanks.

> For best results, I'd use a live cd containing the newest version of dmraid.
> If you get to the point where you need one, but cannot find one, let
> me know and I'll make one for you.

Thanks. First I'll give a try for the distros mentioned first, then fall back to
this option. Just curious: what kind of live cd would you make if needed?

> > RAID set "via_bdafghaihj" already active
> > INFO: Activating linear RAID set "via_bdafghaihj"
> > NOTICE: discovering partitions on "via_bdafghaihj"
> > NOTICE: /dev/mapper/via_bdafghaihj: dos    discovering
>
> Looks good to me!
> You should have /dev/mapper/via_bdafghaihj{1,2,3} partition devices
> available for use now!

I dont have. I still only have /dev/mapper/.
After dmsetup I also have /dev/mapper/via_bdafghaihj, but no numbered ones.

> What does "fdisk -l /dev/mapper/via_bdafghaihj" say?

Lists nothing. (Dir exists.)

> > /dev/sda: via, "via_bdafghaihj", linear, ok, 117210239 sectors, data@ 0
> > /dev/sdb: via, "via_bdafghaihj", linear, ok, 117210239 sectors, data@ 0
>
> Looks reasonable, you can use 'dmsetup' to list the actual table
> entries that dmraid creates.

After install, dmsetup produces the following output:

----------------------------------------------------------------------
# dmsetup status
via_bdafghaihj:
----------------------------------------------------------------------
# dmsetup ls
via_bdafghaihj	(254, 0)
----------------------------------------------------------------------
# dmsetup info
Name:              via_bdafghaihj
State:             ACTIVE
Tables present:    None
Open count:        0
Event number:      0
Major, minor:      254, 0
Number of targets: 0
----------------------------------------------------------------------

>
> HTH
>

Just one more thing - I'd like to mention again, that I'm trying to use dmraid
from an already installed and running (from /dev/sda2) Debian system.
That's why I have sda{1,2,3}. Is there a chance that some partition/metadata
info for sda3 is actually spanned onto the second physical disk? sda1 + sda2
is about 60 Gb, and sda3 is about 60 Gb. That can be a reason for sda3 ntfs
mount failure...

I suppose I will need a dmraid-enabled installer as soon as I switch from JBOD
to RAID0. But before that, I'd like to see it working.

Thanks for the tips and questions. Hope you will have more.
In the meantime, I will check the distros.


András