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Tuesday, September 22, 2009

v490 and MPxIO issue

I was enabling and configuring MPxIO on v490 server and after enabling MPxIO a very strange obsession I discovered on the server, when I enabled MPxIO on this system it started doing FC multipathing to the internal disks. This gave the internal disks MPxIO disk names (c2t[WWPN]d0/c2t[WWPN]d0) and updated the meta device Config etc to point to the new disks.

NOTE: Same observation is with V880 enabling MPxIO includes the internal drives if they're fibre-attached.

This can cause lot of issues at the time of server recovery in our environment. BTW it is not so bad idea to put your internal disks under MPxIO for redundancy, fail-over purpose.

As in our setup we have a problem with such a configuration so we decided to exclude the internal disks for MPxIO, to accomplish this you need to simply first disable to MPxIO using stmsboot -d command and then you need to have below entry in /kernel/drv/fp.conf file -

name="fp" parent="/pci@9,600000/SUNW,qlc@2" port=0 mpxio-disable="yes";

This entry will prevent internal disk to be multipathed.

This line tells Solaris to disable MPxIO on port 0 for all devices whose parent device is /pci@9,600000/SUNW,qlc@2. For sure, similar line should be added for all HBA’s and ports you do not want to have under MPxIO’s control. You can get the parent device from your /var/adm/messages file or from device links pointing to the internal disks.

Like -

# format
AVAILABLE DISK SELECTIONS:
0. c1t0d0
/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000000878bb811,0
1. c1t1d0
/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000000878bc25a,0
2. c4t60050768018E81F5B800000000000142d0
/scsi_vhci/ssd@g60050768018e81f5b800000000000142
3. c4t60050768018E81F5B800000000000145d0
/scsi_vhci/ssd@g60050768018e81f5b800000000000145

c1t0d0s0 & c1t1d0s0 are my internal drives... so I will find physical path for them from /dev or /devices location as below -

# ls -l c1t0d0*
lrwxrwxrwx 1 root root 70 Sep 21 10:04 c1t0d0s0 -> ../../devices/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000000878bb811,0:a
# ls -l c1t1d0*
lrwxrwxrwx 1 root root 70 Sep 21 10:04 c1t1d0s0 -> ../../devices/pci@9,600000/SUNW,qlc@2/fp@0,0/ssd@w21000000878bc25a,0:a

Just a summary -

Enable MPxIO in /kernel/drv/fp.conf

For 280R/480R/v480 and same rage servers add below line to enable MPxIO which will exclude internal drives

mpxio-disable="no";
name="fp" parent="/pci@8,600000/SUNW,qlc@4" port=0 mpxio-disable="yes";

For a v490/v880:

mpxio-disable="no";
name="fp" parent="/pci@9,600000/SUNW,qlc@2" port=0 mpxio-disable="yes";


For v240/v440/v245/v445/T5000 Series/M#000 Series

mpxio-disable="no";

Run the command stmsboot -u to enable MPxIO followed by system reboot.

Hope someone find this helpful!

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