Red Hat Bugzilla – Bug 442550
kdump cannot write the dump out to a multipath device
Last modified: 2012-08-03 15:22:12 EDT
Description of problem:
The kdump initrd does not contain multipath for a boot from SAN configured
system. This makes it so the crash cannot be written out to the
Version-Release number of selected component (if applicable):
RHEL 5.2 snap 4
Steps to Reproduce:
1.Perform a RHEL 5.2-snap4 installation using mpath on the install boot line.
2.Configure kdump to use a multipath device, i.e. /dev/mapper/mpath0p5.
3.Cause a crash via 'echo "c" > /proc/sysrq_trigger'
kdump will be unable to write out the dump as the device does not exist.
The dump gets written out to the multipath device.
Tested using Emulex FC HBA connected to an HP EVA 4000.
Sorry, multipath is something that we're not able to currently do in kdump.
Getting multipath to work consistently in most situations (especially those
where the path callout is a userspace program), is just to fragile at the
moement. I've decided that multipath isn't an option for the time being. I
recommend that you target network based dump target instead (nfs or scp).
Created attachment 390413 [details]
Experimental patch adding multipath support to mkdumprd
This might work for some multipath configurations, use at your own risk!
Multipath is not necessary for kdump to work to SAN disk.
See the section "Dumping to a SAN Device"