[dm-devel] RE: Problem with multipathd and a blacklisted device

[malahal at us.ibm.com]

Ransegnola, Lori [Lori.Ransegnola at hp.com] wrote:
> I sent this question last week and have not heard a thing.  Do you have a suggestion of a better mailing list that I should use for this question?
> 
> Thank you.
> 
> Lori
> 
> > -----Original Message-----
> > From: Ransegnola, Lori
> > Sent: Thursday, March 19, 2009 3:51 PM
> > To: dm-devel at redhat.com
> > Cc: Ransegnola, Lori
> > Subject: Problem with multipathd and a blacklisted device
> >
> > Configuration:
> > --------------
> >
> > I have a multipath configuration set up where 10 disks are
> > multipathed and 2 disks are blacklisted and are not
> > multipathed.  Here are the relevant parts of the multipath.conf file:
> >
> > defaults {
> >         udev_dir                /dev
> >         polling_interval        10
> >         selector                "round-robin 0"
> > #       path_grouping_policy    multibus
> >         getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
> >         prio_callout            /bin/true
> > #       path_checker            readsector0
> >         path_checker            tur
> >         rr_min_io               100
> >         rr_weight               priorities
> >         failback                immediate
> >         no_path_retry           fail
> >         user_friendly_name      yes
> > }
> >
> > blacklist {
> > #       wwid 26353900f02796769
> > #       devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
> > #       devnode "^hd[a-z]"
> >         wwid                    35000c5000a41f72b
> >         wwid                    35000c5000a41f98b
> >         devnode "^cciss!c[0-9]d[0-9]*"
> > }
> >
> >
> > The two disks that are not multipathed have udev rules and
> > are part of a software RAID set.  The devices show up as
> >
> > /etc/udev/rules.d> ls -l /dev/hpdev
> > total 0
> > lrwxrwxrwx 1 root root 7 Mar 18 10:50 sda1 -> ../sda1
> > lrwxrwxrwx 1 root root 7 Mar 18 03:32 sdb1 -> ../sdb1
> >
> > /dev/md0 is created with sda and sdb.  Here is the bottom of
> > the 'mdadm --detail /dev/md0' output:
> >
> > /root> mdadm --detail /dev/md0
> > /dev/md0:
> >         Version
> > ...
> > Failed Devices : 0
> >   Spare Devices : 0
> >
> >            UUID : 94813396:a3e341fc:c5d4b8ba:0617a019
> >          Events : 0.84
> >
> >     Number   Major   Minor   RaidDevice State
> >        0       8        1        0      active sync   /dev/sda1
> >        1       8       17        1      active sync   /dev/sdb1
> > /root>
> >
> > I am running on a Linux RHEL5 U2 system.
> > /etc/udev/rules.d> uname -a
> > Linux n0 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:19 EDT 2007
> > x86_64 x86_64 x86_64 GNU/Linux /etc/udev/rules.d> multipath
> > -v Missing option arguement multipath-tools v0.4.7 (03/12, 2006)
> > ----------------------------
> >
> > Problem:
> >
> > This configuration works well until I do some failure testing
> > with one of the 2 blacklisted devs in the software RAID set.
> > I found that if I temporarily remove disk sda and put it back
> > a minute later the disk path, /dev/hpdev/sda1, is removed, even
> > though it is blacklisted.

What is 'multipath -ll' output before you remove the blacklisted device?
What is 'multipath -ll' output after you put the device back a minute
later?

Thanks, Malahal.