Re: Some md/mdadm bugs

[NeilBrown <neilb@suse.de>]

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On Mon, 06 Feb 2012 19:47:38 +0100 Asdo <asdo@shiftmail.org> wrote:

> One or two more bug(s) in 3.2.2
> (note: my latest mail I am replying to is still valid)
> 
> AUTO line in mdadm.conf does not appear to work any longer in 3.2.2 
> compared to mdadm 3.1.4
> Now this line
> 
> "AUTO -all"
> 
> still autoassembles every array.
> There are many arrays not declared in my mdadm.conf, and which are not 
> for this host (hostname is different)
> but mdadm still autoassembles everything, e.g.:
> 
> # mdadm -I /dev/sdr8
> mdadm: /dev/sdr8 attached to /dev/md/perftest:r0d24, not enough to start 
> (1).
> 
> (note: "perftest" is even not the hostname)

Odd.. it works for me:

# cat /etc/mdadm.conf 
AUTO -all
# mdadm -Iv /dev/sda
mdadm: /dev/sda has metadata type 1.x for which auto-assembly is disabled
# mdadm -V
mdadm - v3.2.2 - 17th June 2011
# 

Can you show the complete output of the same commands (with sdr8 in place of sda of course :-)


> 
> I have just regressed to mdadm 3.1.4 to confirm that it worked back 
> then, and yes, I confirm that 3.1.4 was not doing any action upon:
> # mdadm -I /dev/sdr8
> --> nothing done
> when the line in config was:
> "AUTO -all"
> or even
> "AUTO +homehost -all"
> which is the line I am normally using.
> 
> 
> This is a problem in our fairly large system with 80+ HDDs and many 
> partitions which I am testing now which is full of every kind of arrays....
> I am normally using : "AUTO +homehost -all"  to prevent assembling a 
> bagzillion of arrays at boot, also because doing that gives race 
> conditions at boot and drops me to initramfs shell (see below next bug).
> 
> 
> 
> 
> 
> Another problem with 3.2.2:
> 
> At boot, this is from a serial dump:
> 
> udevd[218]: symlink '../../sdx13' 
> '/dev/disk/by-partlabel/Linux\x20RAID.udev-tmp' failed: File exists
> udevd[189]: symlink '../../sdb1' 
> '/dev/disk/by-partlabel/Linux\x20RAID.udev-tmp' failed: File exists
> 
> And sdb1 is not correctly inserted into array /dev/md0 which hence 
> starts degraded and so I am dropped into an initramfs shell.
> This looks like a race condition... I don't know if this is fault of 
> udev, udev rules or mdadm...
> This is with mdadm 3.2.2 and kernel 3.0.13 (called 3.0.0-15-server by 
> Ubuntu) on Ubuntu oneiric 11.10
> Having also the above bug of nonworking AUTO line, this problem happens 
> a lot with 80+ disks and lots of partitions. If the auto line worked, I 
> would have postponed most of the assembly's at a very late stage in the 
> boot process, maybe after a significant "sleep".
> 
> 
> Actually this race condition could be an ubuntu udev script bug :
> 
> Here are the ubuntu udev rules files I could find, related to mdadm or 
> containing "by-partlabel":

It does look like a udev thing more than an mdadm thing.

What do
   /dev/blkid -o udev -p /dev/sdb1
and
   /dev/blkid -o udev -p /dev/sdx12

report?

NeilBrown



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