Bug 1300415

Hello Brian,
Because there is no PURE FlashArray in our lab, could you provide test result once the package is available?
thanks.

Hello Lin,
We can help with whatever you would need.

Built-in configuration added.

Hello Brian
Could you help feedback test results for this bug?

Thanks
Yi

Yi,
How do I get this version of RedHat to test with PURE?
Thanks,
Brian

You can download the latest RHEL7 packages at:

http://people.redhat.com/~bmarzins/device-mapper-multipath/rpms/RHEL7/bz1300415/

(In reply to Brian Bunker from comment #9)
> Yi,
> How do I get this version of RedHat to test with PURE?
> Thanks,
> Brian

Hello Brian

Could you pls download the package from comment 11 and test it with your PURE environment?

thanks
YI

Yi,

Thanks for the RPMs. What version of RHEL will we need to satisfy the library dependencies? Is any RHEL7 enough?

(In reply to Brian Bunker from comment #13)
> Yi,
> 
> Thanks for the RPMs. What version of RHEL will we need to satisfy the
> library dependencies? Is any RHEL7 enough?

RHEL 7.3 Beta(included that fix) is OK, if you don't have that, RHEL7.2 is OK too,

Thanks
Yi

Yi,
This looks good on RedHat 7.2 with our testing. Is this a RHEL 7.3 or 7.4 target?
Thanks,
Brian

This is already in the rhel-7.3 build.

(In reply to Brian Bunker from comment #15)
> Yi,
> This looks good on RedHat 7.2 with our testing. Is this a RHEL 7.3 or 7.4
> target?
> Thanks,
> Brian

Hi Brian

The fixed package already in the RHEL7.3 build, is it possible for you to try it on 7.3, thanks

Yi

Yi,
We have tried it and we are happy with it.
Brian

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.

https://rhn.redhat.com/errata/RHBA-2016-2536.html

Hi 

  We have setup DM Multipath on PURE Storage of RedHat Linux 7.3
We would like to verify whether it's configured of multipath as "active/active"

How do we verify it is already "active/active" or "active/passive"?

Your advice is appreciated.

Below is the out put info:
[root@new ~]# multipath -ll | grep -i PURE
3624a93707c07ea4dc93341320001f55b dm-5 PURE    ,FlashArray
3624a93707c07ea4dc93341320001f55a dm-4 PURE    ,FlashArray
3624a93707c07ea4dc93341320001f559 dm-3 PURE    ,FlashArray
[root@new ~]#

 multipath -ll
3624a93707c07ea4dc93341320001f55b dm-5 PURE    ,FlashArray
size=2.0T features='0' hwhandler='0' wp=rw
`-+- policy='queue-length 0' prio=1 status=enabled
  |- 1:0:0:3  sdd 8:48   active ready running
  |- 1:0:1:3  sdj 8:144  active ready running
  |- 1:0:2:3  sdq 65:0   active ready running
  |- 1:0:3:3  sdw 65:96  active ready running
  |- 13:0:0:3 sdi 8:128  active ready running
  |- 13:0:1:3 sdn 8:208  active ready running
  |- 13:0:2:3 sdt 65:48  active ready running
  `- 13:0:3:3 sdy 65:128 active ready running
3624a93707c07ea4dc93341320001f55a dm-4 PURE    ,FlashArray
size=3.0T features='0' hwhandler='0' wp=rw
`-+- policy='queue-length 0' prio=1 status=enabled
  |- 1:0:0:2  sdc 8:32   active ready running
  |- 1:0:1:2  sdh 8:112  active ready running
  |- 1:0:2:2  sdo 8:224  active ready running
  |- 1:0:3:2  sdu 65:64  active ready running
  |- 13:0:0:2 sdg 8:96   active ready running
  |- 13:0:1:2 sdm 8:192  active ready running
  |- 13:0:2:2 sdr 65:16  active ready running
  `- 13:0:3:2 sdx 65:112 active ready running
3624a93707c07ea4dc93341320001f559 dm-3 PURE    ,FlashArray
size=100G features='0' hwhandler='0' wp=rw
`-+- policy='queue-length 0' prio=1 status=enabled
  |- 1:0:0:1  sdb 8:16   active ready running
  |- 1:0:1:1  sdf 8:80   active ready running
  |- 1:0:2:1  sdl 8:176  active ready running
  |- 1:0:3:1  sds 65:32  active ready running
  |- 13:0:0:1 sde 8:64   active ready running
  |- 13:0:1:1 sdk 8:160  active ready running
  |- 13:0:2:1 sdp 8:240  active ready running
  `- 13:0:3:1 sdv 65:80  active ready running

Multipath has the concept of pathgroups. A pathgroup contains all of the paths that can be used a the same time, and load balanced across. By an active/active configuration, I assume you mean that you want multipath to load balance across all of the paths to the storage. This is what

path_grouping_policy "multibus"

does in your configuration.

In the "multipath -l" output, the pathgroups look like this:

-+- policy=<path_selector> prio=<path_group_priority> status=<path_group_status>

So looking at the output for 3624a93707c07ea4dc93341320001f559 above, you see

-+- policy='queue-length 0' prio=1 status=enabled

as the only path group, with all the paths under it. This means that all of the paths are being load_balanced over.

If you had multiple pathgroups, so that only some of the paths were able to be used at any one time, the output would look more like this

mpathd (353333330000007d0) dm-6 Linux   ,scsi_debug      
size=8.0M features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='0' wp=rw
|-+- policy='service-time 0' prio=0 status=active
| `- 29:0:0:0 sdf 8:80 active undef unknown
`-+- policy='service-time 0' prio=0 status=enabled
  `- 30:0:0:0 sdg 8:96 active undef unknown

With multiple pathgroup lines and separate paths under each.

So, in short, the output you pasted into Comment 22 corresponds to an active/active setup.

Hi Brian,

   After uncommented those lines and reboot, it's now status=active.
Do you think it's now active/active ? right?
   Can you please confirm that it is right for the "active/active" mode as shown below after un-commented those lines?

   [root@svrhbq-new ~]# grep path_grouping_policy  /etc/multipath.conf
        path_grouping_policy    multibus
                path_grouping_policy    multibus
                path_grouping_policy    multibus
                path_grouping_policy    multibus
[root@svrhbq-new ~]#

[root@svrhbq-new ~]# multipath -ll | grep active
`-+- policy='queue-length 0' prio=1 status=active
  |- 1:0:0:3  sdd 8:48   active ready running
  |- 13:0:0:3 sdi 8:128  active ready running
  |- 1:0:1:3  sdj 8:144  active ready running
  |- 1:0:2:3  sdo 8:224  active ready running
  |- 13:0:1:3 sdp 8:240  active ready running
  |- 1:0:3:3  sdu 65:64  active ready running
  |- 13:0:2:3 sdv 65:80  active ready running
  `- 13:0:3:3 sdy 65:128 active ready running
`-+- policy='queue-length 0' prio=1 status=active
  |- 1:0:0:2  sdc 8:32   active ready running
  |- 13:0:0:2 sdh 8:112  active ready running
  |- 1:0:1:2  sdg 8:96   active ready running
  |- 1:0:2:2  sdm 8:192  active ready running
  |- 13:0:1:2 sdn 8:208  active ready running
  |- 1:0:3:2  sds 65:32  active ready running
  |- 13:0:2:2 sdt 65:48  active ready running
  `- 13:0:3:2 sdx 65:112 active ready running
`-+- policy='queue-length 0' prio=1 status=active
  |- 1:0:0:1  sdb 8:16   active ready running
  |- 1:0:1:1  sde 8:64   active ready running
  |- 13:0:0:1 sdf 8:80   active ready running
  |- 1:0:2:1  sdl 8:176  active ready running
  |- 13:0:1:1 sdk 8:160  active ready running
  |- 1:0:3:1  sdq 65:0   active ready running
  |- 13:0:2:1 sdr 65:16  active ready running
  `- 13:0:3:1 sdw 65:96  active ready running

Your advice is appreciated!

Thanks Brian,