I just noticed that md devices do not show up in /proc/partitions in
2.6.
I realise that they don't actually have partitions and are just 'whole
devices', but other whole devices do appear in /proc/partitions (Along
with their partitions if any).
This seems to be a regression from 2.4 where md devices do appear in
/proc/partitions.
The cause appears to be a patch from 'torvalds' some 15 months ago
(in version 1.36 for drivers/block/genhd.c) which has the comment:
Avoid confusion "mount" and "fsck" - don't show things like
floppies and CD's in /proc/partitions.
It excluded devices that cannot be partitioned, and devices with zero
size from /proc/partitions.
The 'zero size' possibly makes sense (2.4 excludes those), but I would
like to register a vote against excluding devices without partitions,
as this excluded 'md' devices and I would really like them to be
included.
Is there really a good reason for this? How badly does mount get
confused? and is that not the fault of mount?
NeilBrown
At 11:15 AM 27/11/2003, Neil Brown wrote:
>I just noticed that md devices do not show up in /proc/partitions in
>2.6.
[..]
this also caused no end of badness trying to migrate from LVM2 (Linux 2.4)
to DM+LVM2 (Linux 2.6) where the major/minor numbers changed.
while the real fix is to educate lvmcreate_initrd to be more intelligent (i
had to create a new one which includes
mknod/devmap_mknod.sh/mkdir/sed/rm/cat/lvdisplay binaries), it is certainly
a big trap for the unwary that happen to use LVM1/LVM2 as a root volume.
cheers,
lincoln.
On 2003-11-27T11:15:10,
Neil Brown <[email protected]> said:
> I just noticed that md devices do not show up in /proc/partitions in
> 2.6.
Using /proc/partitions for finding the existing block devices /
partitions does seem to be kind of obsolete, as sysfs exports all of
this information too?
So, if anything, I'd drop the confusing redundancy and kill
/proc/partitions - the names there may have little resemblance to how
udev (et al) chose to name the device node in the filesystem anyway.
Sincerely,
Lars Marowsky-Br?e <[email protected]>
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