Sun Storage 2500, 2500-M2, and 6000 Arrays : How To Identify Which Multipath Software Is Used In Red Hat Linux(RHEL)

Asset ID:	1-71-1617385.1
Update Date:	2014-05-07
Keywords:

Solution Type Technical Instruction Sure

Solution 1617385.1 : Sun Storage 2500, 2500-M2, and 6000 Arrays : How To Identify Which Multipath Software Is Used In Red Hat Linux(RHEL)

Applies to:

Sun Storage 2530 Array - Version Not Applicable and later
Sun Storage 6580 Array - Version All Versions and later
Sun Storage 6130 Array - Version All Versions and later
Sun Storage Flexline 380 Array - Version Not Applicable and later
Sun Storage 2530-M2 Array - Version Not Applicable and later
Generic Linux

Goal

Sun Storage 2500, 2500-M2, and 6000 Arrays used in Red Hat Enterprise Linux (RHEL) environments require multipathing software. Two different multipathing solutions are supported:

RDAC/MPP, Redundant Dual Active Controller Multipath Proxy driver (provided by NetApp)

DMMP, Device Mapper Multipath driver (Linux native driver)

This document presents the methods to determine which solution is installed and configured on your server.

DMMP and RDAC/MPP cannot co-exist on an RHEL host. Only one should be installed. DMMP is supported on firmware 07.77.xx and above, and only for these arrays:

Sun Storage 2530-M2 Array
Sun Storage 2540-M2 Array
Sun Storage 6180 Array
Sun Storage 6580 Array
Sun Storage 6780 Array

Solution

How to verify if DMMP is installed and configured

1. Check whether device-mapper is installed.

# rpm -qa |grep device-mapper

device-mapper-1.02.39-1.el5
device-mapper-multipath-0.4.7-34.el5
device-mapper-1.02.39-1.el5
device-mapper-event-1.02.39-1.el5

2. Check that the following device mapper modules are loaded.

# lsmod |grep dm_multipath

dm_multipath           56921 2 dm_round_robin
scsi_dh                42177 2 scsi_dh_rdac,dm_multipath
dm_mod                101649 11 dm_mirror,dm_multipath,dm_raid45,dm_log

3. If yes, check whether the file /etc/multipath.conf is configured. Make sure the lines in italic are commented out in order to enable device mapper.

# This is a basic configuration file with some examples, for device mapper
# multipath.
# For a complete list of the default configuration values, see
# /usr/share/doc/device-mapper-multipath-0.4.7/multipath.conf.defaults
# For a list of configuration options with descriptions, see
# /usr/share/doc/device-mapper-multipath-0.4.7/multipath.conf.annotated

# Blacklist all devices by default. Remove this to enable multipathing
# on the default devices.
#blacklist {   <---
#        devnode "*"   <---
#} <---

## By default, devices with vendor = "IBM" and product = "S/390.*" are
## blacklisted. To enable mulitpathing on these devies, uncomment the
## following lines.
#blacklist_exceptions {
#       device {
#               vendor "IBM"
#               product "S/390.*"
#       }
#}

4. Check whether multipathd is running.

# /etc/init.d/multipathd status
"multipathd (pid 11405) is running..."

5. If yes, check any devices listed using the command below.

# multipath -v2 or #multipath -ll

mpath15 (3600a0b8000473abc0000bafc52fac127) dm-14 SUN,STK6580_6780
[size=10G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=1][enabled]
\_ 8:0:0:2 sds 65:32 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 9:0:0:2 sdu 65:64 [active][faulty]

mpath13 (3600a0b8000473abc0000bb74530aa7da) dm-12 SUN,STK6580_6780
[size=931G][features=0][hwhandler=0][rw]
\_ round-robin 0 [prio=1][enabled]
\_ 9:0:0:0 sdp 8:240 [active][ready]
\_ round-robin 0 [prio=0][enabled]
\_ 8:0:0:0 sdo 8:224 [active][faulty]

If all the above steps succeed, the system is configured for DMMP.

To learn more about how to install and configure DMMP, refer to the document entitled DM Multipath on the RHEL documentation website.

How to verify if RDAC/MPP is installed and configured

1. Check whether mpp modules are loaded.

# lsmod |grep mpp

mppVhba               167040 21
mppUpper              169372 1 mppVhba
scsi_mod              196953 10 scsi_dh,mppVhba,lpfc,scsi_transport_fc,usb_storage,libata,megaraid_sas,mppUpper,sg,sd_mod

2. Check that the OS is booted using the correct initrd image, which would look like below.

# more /etc/grub.conf

        root (hd4,0)
        kernel /vmlinuz-2.6.18-194.el5 ro root=LABEL=/ console=ttyS0,9600n8
        initrd /mpp-2.6.18-194.el5.img   ------------------------------------->initrd image to support mpp

3. Check that mppUtil is installed and any array is listed.

# /usr/sbin/mppUtil -a

Hostname    =
Domainname = (none)
Time        = GMT 03/05/2014 21:57:04

---------------------------------------------------------------
Info of Array Module's seen by this Host.
---------------------------------------------------------------
ID              WWN                      Type     Name
---------------------------------------------------------------
0      xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx FC     6780-a
---------------------------------------------------------------

4. Verify that the driver has discovered the available physical LUNs and created virtual LUNs. The output should look similar to that shown below.

# ls -lR /proc/mpp
/proc/mpp:
total 0
dr-xr-xr-x 4 root root 0 Mar 26 15:34 6780-a

/proc/mpp/6780-a
total 0
dr-xr-xr-x 3 root root 0 Mar 26 15:34 controllerA
dr-xr-xr-x 3 root root 0 Mar 26 15:34 controllerB
-rw-r--r-- 1 root root 0 Mar 26 15:34 virtualLun1
-rw-r--r-- 1 root root 0 Mar 26 15:34 virtualLun2

/proc/mpp/6780-a/controllerA:
total 0
dr-xr-xr-x 2 root root 0 Mar 26 15:34 lpfc_h9c0t0

/proc/mpp/6780-a/controllerA/lpfc_h9c0t0:
total 0
-rw-r--r-- 1 root root 0 Mar 26 15:34 LUN1
-rw-r--r-- 1 root root 0 Mar 26 15:34 LUN2
-rw-r--r-- 1 root root 0 Mar 26 15:34 UTM_LUN31

/proc/mpp/6780-a/controllerB:
total 0
dr-xr-xr-x 2 root root 0 Mar 26 15:34 lpfc_h8c0t0

/proc/mpp/6780-a/controllerB/lpfc_h8c0t0:
total 0
-rw-r--r-- 1 root root 0 Mar 26 15:34 LUN1
-rw-r--r-- 1 root root 0 Mar 26 15:34 LUN2
-rw-r--r-- 1 root root 0 Mar 26 15:34 UTM_LUN31

5.The lsvdev utility provides a map of your array LUNs to their Linux block devices.

# /opt/mpp/lsvdev
        Array Name      Lun    sd device
        -------------------------------------
        6780-a    1     -> /dev/sdo
        6780-a          2     -> /dev/sdp

If all of the above are true, then the volumes on the array are configured under RDAC/MPP.

For further information, refer to the Sun StorageTek RDAC Multipath Failover Driver Installation Guide for Linux OS.

To troubleshoot RDAC/MPP related issue please collect the following and contact Oracle Support.

#sosreport

#/opt/mpp/mppSupport -a -->This command will generate a zip file.

For more details on how to collect logs under RHEL, please refer to <Document 1010058.1> How to Gather Information on Red Hat Enterprise Linux Systems

/opt/mpp/mppSupport -a ---> This command will collect mpp related logs. The file will be saved as mppSupportdata*.tar.gz file under /tmp.

Mainly look at following directories to know more details related to MPP.

scsi_hba_info
linuxmpp_info

Under "sosreport" following files/directories will provide you with RDAC/MPP details.

proc/scsi/mpp/*
proc/scsi/scsi
lsmod
boot/grub/grub.conf
var/log/messages*

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