Multipath now includes support for Ceph RADOS block devices.
RDB devices need special `uid` handling and their own checker function with the ability to repair devices. With this release, it is now possible to run multipath on top of RADOS block devices. Note, however, that the multipath RBD support should be used only when an RBD image with the `exclusive-lock` feature enabled is being shared between multiple clients.
Description of problem:
This is a request to merge the Ceph RBD multipathd path checker.
This is required by the ceph iSCSI HA project to support unclean failovers.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
Just making a note about the patches needed for this bz:
Author: Hannes Reinecke <email@example.com>
Date: Wed Nov 11 13:38:57 2015 +0100
libmultipath: correctly initialize pp->sg_id
The default SCSI protocol is 'SCSI_PROTOCOL_UNSPEC';
'0' is SCSI_PROTOCOL_FCP.
Signed-off-by: Hannes Reinecke <firstname.lastname@example.org>
and the final version of these patches:
Can we change the doc info so it does not sound like this is for general RBD use.
The multipath RBD support should only be used when you are sharing a RBD image, that has the exclusive-lock feature enabled, between multiple clients.
Basically, you cannot do fancy things people normally expect for multipath support like failover across network paths or round robin over multiple network paths. The support just handles failures on paths that are blacklisted due to another client taking the RBD exclusive-lock.
Mike: I added your additional comment (just slightly edited) but I wasn't sure whether I need to go into detail on what this feature does not support.
Steve, what you have in comment #12 should be good.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.