Re: Bug#381150: still not able to handle partitionable arrays

Re: Bug#381150: still not able to handle partitionable arrays

[Robert Millan]

It seems there are problems with accessing software RAID in devices with
pathnames like /dev/md_d0p1

On Sat, Jan 06, 2007 at 05:59:16PM +0100, martin f krafft wrote:
> 
> grub2 1.95-2 still does not support partitionable arrays:
> 
> [...]
> 
> debian# grub-probe -v /boot
> grub-probe: info: changing current directory to /dev
> grub-probe: info: changing current directory to i2o
> grub-probe: info: changing current directory to ataraid
> grub-probe: info: changing current directory to shm
> grub-probe: info: changing current directory to network
> grub-probe: info: changing current directory to input
> grub-probe: info: changing current directory to cciss
> grub-probe: info: changing current directory to mapper
> grub-probe: info: changing current directory to ida
> grub-probe: info: changing current directory to rd
> grub-probe: info: changing current directory to pts
> cannot find a GRUB drive for md_d0p1.

-- 
Robert Millan

My spam trap is honeypot@aybabtu.com.  Note: this address is only intended
for spam harvesters.  Writing to it will get you added to my black list.

Re: Bug#381150: still not able to handle partitionable arrays

[Yoshinori K. Okuji]

On Saturday 05 May 2007 01:29, Robert Millan wrote:
> It seems there are problems with accessing software RAID in devices with
> pathnames like /dev/md_d0p1

Is there any specification about device names on Linux? I have been seeing 
Linux adding more and more new inconsistent device names for years, and it 
seems to be no end in this game.

Okuji

Re: Bug#381150: still not able to handle partitionable arrays

[Robert Millan]

On Mon, May 07, 2007 at 09:03:48PM +0200, Yoshinori K. Okuji wrote:
> On Saturday 05 May 2007 01:29, Robert Millan wrote:
> > It seems there are problems with accessing software RAID in devices with
> > pathnames like /dev/md_d0p1
> 
> Is there any specification about device names on Linux? I have been seeing 
> Linux adding more and more new inconsistent device names for years, and it 
> seems to be no end in this game.

Not that I know of.  But a few days ago I was toying with the idea that grub
could theoreticaly become device path agnostic.  Maybe this doesn't apply to
specific things like software RAID / LVM, but for most weird devices it's
probably feasible.

-- 
Robert Millan

My spam trap is honeypot@aybabtu.com.  Note: this address is only intended
for spam harvesters.  Writing to it will get you added to my black list.

Re: Bug#381150: still not able to handle partitionable arrays

[Jeroen Dekkers]

At Mon, 7 May 2007 22:00:50 +0200,
Robert Millan wrote:
> 
> On Mon, May 07, 2007 at 09:03:48PM +0200, Yoshinori K. Okuji wrote:
> > On Saturday 05 May 2007 01:29, Robert Millan wrote:
> > > It seems there are problems with accessing software RAID in devices with
> > > pathnames like /dev/md_d0p1
> > 
> > Is there any specification about device names on Linux? I have been seeing 
> > Linux adding more and more new inconsistent device names for years, and it 
> > seems to be no end in this game.

The best part is actually that it's not the only name, from the mdadm manpage:

"""
The standard names for non-partitioned arrays (the only sort of md array available in 2.4 and earlier) either of

              /dev/mdNN
              /dev/md/NN

where NN is a number.  The standard names for partitionable arrays (as available from 2.6 onwards) is one of

              /dev/md/dNN
              /dev/md_dNN

Partition numbers should be indicated by added "pMM" to these, thus "/dev/md/d1p2". 
"""

> Not that I know of.  But a few days ago I was toying with the idea that grub
> could theoreticaly become device path agnostic.  Maybe this doesn't apply to
> specific things like software RAID / LVM, but for most weird devices it's
> probably feasible.

I've been thinking about that too, because the current way seems a bit
fragile. But then you're looking up the device major and minor number
for partionable RAID arrays and you see that it's in the
"LOCAL/EXPERIMENTAL USE" range. Not very useful either...

Jeroen Dekkers

Re: Bug#381150: still not able to handle partitionable arrays

[Yoshinori K. Okuji]

On Thursday 17 May 2007 23:25, Jeroen Dekkers wrote:
> I've been thinking about that too, because the current way seems a bit
> fragile. But then you're looking up the device major and minor number
> for partionable RAID arrays and you see that it's in the
> "LOCAL/EXPERIMENTAL USE" range. Not very useful either...

Hmm...

Okuji

Re: Bug#381150: still not able to handle partitionable arrays

[Jeroen Dekkers]

At Sat, 5 May 2007 01:29:07 +0200,
Robert Millan wrote:
> It seems there are problems with accessing software RAID in devices with
> pathnames like /dev/md_d0p1
> 
> On Sat, Jan 06, 2007 at 05:59:16PM +0100, martin f krafft wrote:
> > 
> > grub2 1.95-2 still does not support partitionable arrays:
> > 
> > [...]
> > 
> > debian# grub-probe -v /boot
> > grub-probe: info: changing current directory to /dev
> > grub-probe: info: changing current directory to i2o
> > grub-probe: info: changing current directory to ataraid
> > grub-probe: info: changing current directory to shm
> > grub-probe: info: changing current directory to network
> > grub-probe: info: changing current directory to input
> > grub-probe: info: changing current directory to cciss
> > grub-probe: info: changing current directory to mapper
> > grub-probe: info: changing current directory to ida
> > grub-probe: info: changing current directory to rd
> > grub-probe: info: changing current directory to pts
> > cannot find a GRUB drive for md_d0p1.

My latest commit to GRUB2 CVS should fix this.

Jeroen Dekkers

Re: Bug#381150: still not able to handle partitionable arrays

[Robert Millan]

tags 381150 fixed-upstream
thanks

On Fri, May 18, 2007 at 01:28:15AM +0200, Jeroen Dekkers wrote:
> > > cannot find a GRUB drive for md_d0p1.
> 
> My latest commit to GRUB2 CVS should fix this.

Martin, can you check if things work for you before next upload ?

-- 
Robert Millan

My spam trap is honeypot@aybabtu.com.  Note: this address is only intended
for spam harvesters.  Writing to it will get you added to my black list.

Re: Bug#381150: still not able to handle partitionable arrays

[Michael Guntsche]

On May 18, 2007, at 1:28, Jeroen Dekkers wrote:

>
> My latest commit to GRUB2 CVS should fix this.
>
> Jeroen Dekkers

Hello,

This also seems to fix the detection for LVM devices. grub-probe -t 
{drive,device} works now, partmap on the other hand still fails.

<snip>
grub-probe: info: changing current directory to /dev/mapper
grub-probe: info: opening fatoftheland-main
grub-probe: error: Cannot detect partition map for fatoftheland-main

For now I install everything manually but maybe this can be fixed as  
well.

Kind regards,
Michael

Re: Bug#381150: still not able to handle partitionable arrays

[Jeroen Dekkers]

At Fri, 18 May 2007 09:34:53 +0200,
Michael Guntsche wrote:
> This also seems to fix the detection for LVM devices. grub-probe -t 
> {drive,device} works now, partmap on the other hand still fails.

That was actually a different fix that I committed on the 16th.
 
> <snip>
> grub-probe: info: changing current directory to /dev/mapper
> grub-probe: info: opening fatoftheland-main
> grub-probe: error: Cannot detect partition map for fatoftheland-main
> 
> For now I install everything manually but maybe this can be fixed as  
> well.

This is actually the same problem as with software RAID, currently
grub-probe doesn't have a way to get the underlying device and lookup
the partition map. Maybe I've time to look into this later today, but
I've first some other things to do.

Jeroen Dekkers