Multipath path down error

kathirvel · 03-28-2016, 01:36 PM

Hi,

I have a server running with RHEL5.5 on which I get following error for multi-path disks.

-----

root@segotl0161# multipath -ll
sdaa: checker msg is "readsector0 checker reports path is down"
sdac: checker msg is "readsector0 checker reports path is down"
sdad: checker msg is "readsector0 checker reports path is down"
sdaf: checker msg is "readsector0 checker reports path is down"
sdag: checker msg is "readsector0 checker reports path is down"
sdah: checker msg is "readsector0 checker reports path is down"
sdam: checker msg is "readsector0 checker reports path is down"
sdan: checker msg is "readsector0 checker reports path is down"
sdao: checker msg is "readsector0 checker reports path is down"
sdap: checker msg is "readsector0 checker reports path is down"
sdau: checker msg is "readsector0 checker reports path is down"
sdav: checker msg is "readsector0 checker reports path is down"
sday: checker msg is "readsector0 checker reports path is down"
sda: checker msg is "readsector0 checker reports path is down"
sdba: checker msg is "readsector0 checker reports path is down"
sdbc: checker msg is "readsector0 checker reports path is down"
sdbd: checker msg is "readsector0 checker reports path is down"
sdou: checker msg is "readsector0 checker reports path is down"
sdov: checker msg is "readsector0 checker reports path is down"
sdow: checker msg is "readsector0 checker reports path is down"
sdox: checker msg is "readsector0 checker reports path is down"
sdo: checker msg is "readsector0 checker reports path is down"
sdpa: checker msg is "readsector0 checker reports path is down"
sdpe: checker msg is "readsector0 checker reports path is down"
sdpf: checker msg is "readsector0 checker reports path is down"
sdpg: checker msg is "readsector0 checker reports path is down"
sdpi: checker msg is "readsector0 checker reports path is down"
sdpj: checker msg is "readsector0 checker reports path is down"
sdpl: checker msg is "readsector0 checker reports path is down"
sdpm: checker msg is "readsector0 checker reports path is down"
sdpn: checker msg is "readsector0 checker reports path is down"
sdps: checker msg is "readsector0 checker reports path is down"
sdpt: checker msg is "readsector0 checker reports path is down"
sdpu: checker msg is "readsector0 checker reports path is down"
sdpv: checker msg is "readsector0 checker reports path is down"
sdp: checker msg is "readsector0 checker reports path is down"
sdqa: checker msg is "readsector0 checker reports path is down"
sdqb: checker msg is "readsector0 checker reports path is down"
sdqe: checker msg is "readsector0 checker reports path is down"
sdqg: checker msg is "readsector0 checker reports path is down"

360000970000295700380533033414146 dm-84 EMC,SYMMETRIX
[size=100G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=4][active]
\_ 2:0:1:32 sdcy 70:96 [active][ready]
\_ 2:0:3:32 sdjf 8:400 [active][ready]
\_ 1:0:2:32 sdse 135:288 [active][ready]
\_ 1:0:3:32 sdvt 68:752 [active][ready]
360000970000295700380533033413637 dm-75 EMC,SYMMETRIX
[size=150G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=4][active]
\_ 2:0:1:23 sdcp 69:208 [active][ready]
\_ 2:0:3:23 sdiw 8:256 [active][ready]
\_ 1:0:2:23 sdrv 134:400 [active][ready]
\_ 1:0:3:23 sdvk 68:608 [active][ready]
360000970000295700380533033394637 dm-61 EMC,SYMMETRIX
[size=350G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=0][enabled]
\_ 2:0:1:9 sdcb 68:240 [failed][faulty]
\_ 2:0:3:9 sdii 135:32 [failed][faulty]
\_ 1:0:2:9 sdrh 133:432 [failed][faulty]
\_ 1:0:3:9 sduw 67:640 [failed][faulty]
360000970000295700381533033413346 dm-25 EMC,SYMMETRIX
[size=22G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=4][active]
\_ 2:0:0:45 sdat 66:208 [active][ready]
\_ 2:0:2:45 sdha 133:0 [active][ready]
\_ 1:0:0:45 sdnh 71:304 [active][ready]
\_ 1:0:1:45 sdpz 131:400 [active][ready]

----------------

Following is multipath configuration.

root@segotl0161# cat /etc/multipath.conf
defaults {
user_friendly_names no
}
root@segotl0161#

Is this a serious issue , Please help me on this issue.

Thanks,
Kathirvel.S

MensaWater · 03-28-2016, 04:03 PM

This post gives a little background into a similar issue someone had:
https://www.redhat.com/archives/dm-d.../msg00061.html

Based on that you should have a look at "man multipath.conf" and search for "hardware_handler" and "patch_checker". You'll see mention of what you should use for EMC disk arrays like Symmetrix.

For what it is worth the entry we had on RHEL5 when we still had a Symmetrix (which we don't any longer) was:

Code:

       device {
               vendor                  "EMC"
               product                 "SYMMETRIX"
               getuid_callout          "/sbin/scsi_id -g -u -ppre-spc3-83 -s /block/%n"
               features                "0"
               hardware_handler        "0"
               path_grouping_policy    multibus
               no_path_retry           6
               rr_weight               uniform
               rr_min_io               1000
               path_checker            tur
       }

You might want to use the syminq command provided by EMC to look at what devices it sees to determine if the multipath devices you see below the errors are all that you should see.