Automatic failback with multipath

Automatic failback with multipath

[Dale.R.Fowle]

Hi all,

I recently saw a workaround that was given in a previous query about
automatic failback with EMC arrays. I'm testing a different array, but I
tried the 'failback immediate' option in the /etc/multipath.conf file and
it doesn't do automatic failback. I wound up having to reset the path with
'multipath -v2 -p failover' for multipath to scan the re-enabled path and
update it's own status. Am I missing something or is this a known issue?

Also, is this an issue just with multipath-tools 0.4.4 or has anyone seen
this in 0.4.5.? The only reason I'm not using 0.4.5 is because I've had
issues getting it to make/compile.

Any help would be appreciated.

Thanks,
Dale

Dale Fowle
Seagate Technology
Colorado Springs, CO
719-388-5584

RE: Automatic failback with multipath

[goggin, edward]

This issue was somehow erroneously associated with ONLY
EMC CLARiiON arrays but is by no means restricted to them.

The same problem will happen with dm multipath and any
storage array which has multiple path groups of differing
priorities configured for a block device.

I believe the problem has existed for quite some time and
does span the 0.4.4 and 0.4.5 releases of multipath-tools.

The previously mentioned work around will work for all
storage array types.

> -----Original Message-----
> From: dm-devel-bounces@redhat.com 
> [mailto:dm-devel-bounces@redhat.com] On Behalf Of 
> Dale.R.Fowle@seagate.com
> Sent: Friday, November 11, 2005 12:21 PM
> To: dm-devel@redhat.com
> Subject: [dm-devel] Automatic failback with multipath
> 
> 
> Hi all,
> 
> I recently saw a workaround that was given in a previous query about
> automatic failback with EMC arrays. I'm testing a different 
> array, but I
> tried the 'failback immediate' option in the 
> /etc/multipath.conf file and
> it doesn't do automatic failback. I wound up having to reset 
> the path with
> 'multipath -v2 -p failover' for multipath to scan the 
> re-enabled path and
> update it's own status. Am I missing something or is this a 
> known issue?
> 
> Also, is this an issue just with multipath-tools 0.4.4 or has 
> anyone seen
> this in 0.4.5.? The only reason I'm not using 0.4.5 is 
> because I've had
> issues getting it to make/compile.
> 
> Any help would be appreciated.
> 
> Thanks,
> Dale
> 
> Dale Fowle
> Seagate Technology
> Colorado Springs, CO
> 719-388-5584
> 
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> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
> 

Re: Automatic failback with multipath

[Bernd Zeimetz]

Hi,

> Any help would be appreciated.

You should definitely use actual multipath-tools, best is to get them from git 
and compile them. If you have trouble with that send me the output of your 
compiler and I'll try to figure out what's wrong. Also check
http://christophe.varoqui.free.fr/wiki/wakka.php?wiki=TestedEnvironments
- at the bottom of the page is my short summary about running an EMC CX with 
multipath-tools - at least what I've figured out. There's also a link to a 
longer thread on the dm-devel list, you probably want to read it.


Bye,

Bernd