Red Hat Bugzilla – Bug 215505
DM multipath devices are not created - for the luns with dev_t minor numbers > 256
Last modified: 2010-01-11 21:27:38 EST
DM devices are not being created for the Luns with minor numbers greater than
256 when mpath_prio_alua is used as path_prio_callout routine.
Steps to Reproduce:
1. present larger set of LUNs (with more than 2 HBAs in the host and
having exposed paths from each HBA for the Lun) from HSV111 array to the host
2. Following are the Parameters in /etc/mutilapth.conf for HSV210 Devices
prio_callout "/sbin/mpath_prio_alua %d"
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
path_selector "round-robin 0"
4. Reboot the system
DM devices are not created for HSV111 Luns for the paths with dev_t minor
numbers greater than 256
Initial investigation and analysis:
The issue seems to be b'cos of mpath_prio_alua and its argument as %d.
With "multipath -v3" output, the messages shows that, "mpath_prio_alua" with "%
d" as argument return -1 for the devices with dev_t minor numbers greater than
For Example, the devices with dev_t maj:min numbers as 71:256, 68:384 reports
these error, and the multipath devices are not getting vreated for those Luns.
But, "mpath_prio_alua" with "%n" for the same devices returns the valid
priority for those devices and the multipath devices are succesfully created.
"mpath_prio_alua %d" and "mpath_prio_alua %n" behave differently with the later
one works well with all devices and the earlier one doesnt work with the
devices having minor number greater than 256.
Pulled in the upstream patch to fix this issue.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.