Hi,

2.6.32-696.1.1.el6.x86_64

3.10.0-514.10.2.el7.x86_64

I tried ioping test from different group of servers using multipath, members of different storage group (different lun, different raid ecc), and everyone report latency.

I tried the same test (ioping) on a server with powerpath instead of multipath, with a dedicated raid group and ioping don't report latency.

2017-05-13 2:00 GMT+02:00 Juan Pablo <pablo.localhost@gmail.com>:

sorry to jump in, but what kernel version are you using? had similar issue with kernel 4.10/4.11

2017-05-12 16:36 GMT-03:00 Stefano Bovina <bovy89@gmail.com>:

Hi,

a little update:

The command multipath -ll hung when executed on the host while the problem occur (nothing logged in /var/log/messages or dmesg).

I tested latency with ioping:

ioping /dev/6a386652-629d-4045-835b-21d2f5c104aa/metadata

Usually it return "time=15.6 ms", sometimes return "time=19 s" (yes, seconds)

Systems are up to date and I tried both path_checker (emc_clariion and directio), without results.

(https://access.redhat.com/solutions/139193, it refers to the Rev A31 of EMC document; last is A42 and suggest emc_clariion).

Any idea or suggestion?

Thanks,

Stefano

2017-05-08 11:56 GMT+02:00 Yaniv Kaul <ykaul@redhat.com>:

On Mon, May 8, 2017 at 11:50 AM, Stefano Bovina <bovy89@gmail.com> wrote:

Yes,

this configuration is the one suggested by EMC for EL7.

https://access.redhat.com/solutions/139193 suggest that for alua, the patch checker needs to be different.

Anyway, it is very likely that you have storage issues - they need to be resolved first and I believe they have little to do with oVirt at the moment.

Y.

 

By the way,

"The parameters rr_min_io vs. rr_min_io_rq mean the same thing but are used for device-mapper-multipath on differing kernel versions." and rr_min_io_rq default value is 1, rr_min_io default value is 1000, so it should be fine.

2017-05-08 9:39 GMT+02:00 Yaniv Kaul <ykaul@redhat.com>:

On Sun, May 7, 2017 at 1:27 PM, Stefano Bovina <bovy89@gmail.com> wrote:

Sense data are 0x0/0x0/0x0

Interesting - first time I'm seeing 0/0/0. The 1st is usually 0x2 (see [1]), and then the rest [2], [3] make sense.

A google search found another user with Clarion with the exact same error[4], so I'm leaning toward misconfiguration of multipathing/clarion here.

Is your multipathing configuration working well for you?

Are you sure it's a EL7 configuration? For example, I believe you should have rr_min_io_rq and not rr_min_io .

Y.

[1] http://www.t10.org/lists/2status.htm

[2] http://www.t10.org/lists/2sensekey.htm

[3] http://www.t10.org/lists/asc-num.htm

[4] http://www.linuxquestions.org/questions/centos-111/multipath-problems-4175544908/

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