Red Hat Bugzilla – Bug 168393
SAN boot fails if install target is multipathed
Last modified: 2010-05-20 11:01:20 EDT
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Description of problem:
I install my OS on an EMC Clariion LUN. After the install completes the host gets rebooted. Once the host is back up I find that /boot is not mounted. In the /var/log/messages file is see errors LABEL=/boot duplicate not mounted. If all but one active paths are removed I do not see the problem. The issue is that during the system boot up the LABEL does not appear to be in any way compared to the duplicate LABEL's. In a multipath enviroment every device will need to be available through several alternate paths. A simple check for a unique disk identifier would most likely fix the problem.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Install OS on multipath target with 2 or more active methods of connection
Expected Results: /boot was not mounted.
*** Bug 168395 has been marked as a duplicate of this bug. ***
This creates a problem for disks slated to be used in the native multipath
FYI My testing on another 2.6 based Enterprise Server Linux showed that it can
correctly identify labeled multipath LUNS. This testing also showed that when 2
LUNS were given the same label it was able to correctly fail to mount the
device with the duplicate label error. My hope in bring this to light (adding
this comment) is that a fix for the problem might be available in an up-stream
version. I thought that if RedHat were aware of a potential fix for the problem
it might help resolve this.
Arthur - currently, Red Hat is not supporting booting from the SAN with
Are you using PowerPath or the device-mapper-multipath? Are you using LVM2 in
conjunction with the multipath functionality?
I was attempting to use the native failover product.
I got as far a installing the OS on a network drive and rebooting. the /boot
partition did not mount because it saw multiple copies of the disk label. My
plan was to test the device-mapper-multipath bundled with Update 2. Also LVM is
configured during the initial install for the / partition. When is boot from
SAN targeted for support in RHEL4 using MPIO?
At this point in time, I am not sure if or when SAN boot is going to be
supported when using the device-mapper MPIO.
Alasdair - do you have any insight into this?
We have no plans to add multipath fixes to anaconda for RHEL4. That support first appeared in RHEL5.1 (or .2) and was very complicated to get right. It's too much work to backport into RHEL4 without the potential for major destabilization.