Sun Storage A1000 Array
 
Veritas Volume Manager (VxVM) Software
 

GCS>Sun Microsystems>Storage - Disk>Modular Disk - Other
 

This problem affects following products:-

VERITAS VOLUME MANAGER (VxVM) version 4.0
Sun StorEdge[TM] A1000 Array
Sun StorEdge[TM] A3500 Array

After installing, or upgrading to Veritas Volume Manager 4.0, corresponding LUNs on separate A1000s or A3500s may show up as the same device in Volume Manager configuration.

For example:

Two A1000s with only LUN 0 will show up as two devices in format and the Raid Manager utility /usr/lib/osa/bin/lad as follows:-

 #format
0. c0t0d0 <SUN9.0G cyl 4924 alt 2 hd 27 sec 133>
/sbus@1f,0/SUNW,fas@e,8800000/sd@0,0
1. c1t1d0 <Symbios-StorEDGEA1000-0003 cyl 248 alt 2 hd 64 sec 64>
/pseudo/rdnexus@1/rdriver@1,0
2. c2t2d0 <Symbios-StorEDGEA1000-0003 cyl 248 alt 2 hd 64 sec 64>
/pseudo/rdnexus@2/rdriver@2,0

 # lad
c1t1d0 1T02699027 LUNS: 0
c2t2d0 1T94412912 LUNS: 0 

Notice that the above LUNs are from two different A1000s.

Now if you check the above disks in volume manager configuration using the
vxdisk command, we see only one entry for the two A1000 LUNs above.

 # vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
c0t0d0s2     auto:none       -            -            online
c1t1d0s2     auto:none       -            -            online 

Notice that only c1t1d0s2 appears in the list and c2t2d0s2 is missing. Moreover, if we check the multipath status for the device listed above, we will see that the c2t2d0s2 is seen as an alternate path to c1t1d0s2 which is wrong since they are two different and unique disks(LUNs).

 #vxdisk list c1t1d0s2
Device:    c1t1d0s2
devicetag: c1t1d0
type:      auto
info:      format=none
flags:     online ready private autoconfig invalid
pubpaths:  block=/dev/vx/dmp/c1t1d0s2 char=/dev/vx/rdmp/c1t1d0s2
Multipathing information:
numpaths:   2                         <-- Note: two paths as opposed to one.
c1t1d0s2        state=enabled
c2t2d0s2        state=enabled

This can confuse the volume manager, and hence, the device paths can get messed up and the customer may have booting problems after upgrading to Volume manager 4.0.
This can also occur for more than two arrays, and LUNs other than 0.

This has been reproduced and bug 5041496 filed for this issue. As per the bug update, this is scheduled to be fixed in the next patch for Volume Manager 4.0.

The immediate work around to fix this issue is to disable DMP IE supress multipathing for the affected controllers. We can do this by running vxdiskadm and choosing option 17, suboption 6 and then run vxdctl enable.

Once DMP is disabled, all LUNS will show up in vxdisk list as devices as
shown below. After supressing multipathing for each controller value to each
A1000, the vxdisk output looked fine...

 # vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
c0t0d0s2     auto:none       -            -            online
c1t1d0s2     auto:none       -            -            online
c2t2d0s2     auto:none       -            -            online 

Please see escalation 1-5985854, Case 64400341 and also bug 5041496 for more details.

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