Re: Local Partitions detected as Multipath Device

[Elvir Kuric <ekuric@xxxxxxxxxx>]

On 10/25/2013 07:29 AM, Zama Ques wrote:

Creating a new RAMDISK resolved the issue as suggested by Elvir Kuric after blacklisting the local disk in multipath.conf .

====
$ df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda8             43112964  19708732  21214204  49% /
tmpfs                 32978736     25836  32952900   1% /dev/shm
/dev/sda1               198337     66006    122091  36% /boot
/dev/sda6             10079084    840160   8726924   9% /opt
/dev/mapper/mpathbp1  51606124    184136  48800552   1% /webdata
/dev/mapper/mpathcp1 209690016   3414728 206275288   2% /sharedweb
===

Other options of  setting following parameter  " find_multipaths  yes"  did not helped to resolve the issue.

Thanks all for the replies and suggestions.

Thanks

Zaman

On Tuesday, 22 October 2013 4:58 PM, Elvir Kuric <ekuric@xxxxxxxxxx> wrote:

On 10/22/2013 12:17 PM, Zama Ques wrote:

My local partitions are detected as multipath device

$multipath -l

mpathb (360014380125d90420000a000003e0000) dm-9 HP,HSV450
size=200G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=0 status=active
`- 3:0:0:1 sdb 8:16 active undef running
mpatha (3600508b1001c02143bc59c6862d97353) dm-0 HP,LOGICAL VOLUME
size=137G features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=0 status=active
`- 0:0:0:1 sda 8:0  active undef running

I added the following lines in multipath.conf so that local partitions are not considered as multipath device

blacklist {
   wwid 3600508b1001c02143bc59c6862d97353
}

Executed the following commands after that .

#service multipathd reload

# multipath -F
Oct 22 12:10:42 | mpathb: map in use
Oct 22 12:10:42 | mpatha: map in use

So , tried rebooting the server , but no luck . Any clues to resolve the issue will be highly appreciated .

Thanks

Zaman

hi,

/me wonders what OS ( and version ) is in use? service multipathd relaod ... suggest it is something RHEL based ( not 100 % sure )

Check /etc/multipath/* files ( if rhel 6 )  and see is there WWID from above, and also check initramfs ( RHEL 6 ) or initrd file  ( RHEL 5 ) from /boot

do below

# mkdir /tmp/initrdtest
# cp /boot/initramfs-$$$$.img ( or initrd ... ) /tmp/initrdtest

unpack it

# cd tmp/initrdtest

# zcat initrd.img | cpio -i

and check what is there for multiapth devices written.

In short, I think you will need to ensure there are not records for devices you want to blacklist in /etc/multipath/* ( rhel 6 ) or /var/lib/multipath/*   ( rhel 5 ) and rebuild initramfs / initrd ( depending is it RHEL 5 - initrd / RHEL 6 -initramfs  ) once these records are not present.Rebuilding initrd/initramfs will pick values from /etc/multipath/*  ( rhel 6 ) or /var/lib/multipath/ ( rhel 5 )

to rebuild initrd/initramfs check docs out there  but in short process is ( after you remove records for WWID from wwid and bindings files - read above )


RHEL 5:

# cd /boot
# cp initrd-$(uname -r).img initrd-$(uname -r).img.backup [ make backup ]
# mkinitrd -v -f initrd-$(uname -r).img
# reboot ( to boot to new initramfs )

RHEL 6:

same as above with small corrections ;)


# cd /boot
# cp initramfs-$(uname -r).img initramfs-$(uname -r).img.backup [ make backup ]
# dracut -v -f initramfs-$(uname -r).img
# reboot ( to boot to new initramfs )


good reading https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/DM_Multipath/config_file_blacklist.html  

hope this helps

Kind regards,

-- 
Elvir Kuric, Senior Technical Support Engineer / Red Hat / GSS EMEA / 

--
Linux-cluster mailing list
Linux-cluster@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/linux-cluster

Cool, thank you for feedback.If you are Red Hat customer and have valid contract, use benefit of subscription and next time you have problem with RHEL open case via Red Hat customer portal https://access.redhat.com

Kind regards,

Elvir Kuric

-- 
Linux-cluster mailing list
Linux-cluster@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/linux-cluster