Displaying Multipaths to a VM Disk
The vxdisk command is used to display the multipathing information for a particular metadevice. The metadevice is a device representation of a particular physical disk having multiple physical paths from the I/O controller of the system. In VxVM, all the physical disks in the system are represented as metadevices with one or more physical paths.
You can use the vxdisk path command to display the relationships between the device paths, disk access names, disk media names and disk groups on a system as shown here:
# vxdisk path
SUBPATH DANAME DMNAME GROUP STATE
c1t0d0 c1t0d0 mydg01 mydg ENABLED
c4t0d0 c1t0d0 mydg01 mydg ENABLED
c1t1d0 c1t1d0 mydg02 mydg ENABLED
c4t1d0 c1t1d0 mydg02 mydg ENABLED
.
.
.
This shows that two paths exist to each of the two disks, mydg01 and mydg02, and also indicates that each disk is in the ENABLED state.
To view multipathing information for a particular metadevice, use the following command:
# vxdisk list devicename
For example, to view multipathing information for c1t0d3, use the following command:
# vxdisk list c1t0d3
Typical output from the vxdisk list command is as follows:
Device: c1t0d3
devicetag: c1t0d3
type: simple
hostid: zort
disk: name=mydg04 id=962923652.362193.zort
timeout: 30
group: name=mydg id=962212937.1025.zort
info: privoffset=128
flags: online ready private autoconfig autoimport imported
pubpaths: block=/dev/vx/dmp/c1t0d3
privpaths: char=/dev/vx/rdmp/c1t0d3
version: 2.1
iosize: min=1024 (bytes) max=64 (blocks)
public: slice=0 offset=1152 len=4101723
private: slice=0 offset=128 len=1024
update: time=962923719 seqno=0.7
headers: 0 248
configs: count=1 len=727
logs: count=1 len=110
Defined regions:
config priv 000017-000247[000231]:copy=01 offset=000000 disabled
config priv 000249-000744[000496]:copy=01 offset=000231 disabled
log priv 000745-000854[000110]:copy=01 offset=000000 disabled
lockrgn priv 000855-000919[000065]: part=00 offset=000000
Multipathing information:
numpaths: 2
c1t0d3 state=enabled type=secondary
c4t1d3 state=disabled type=primary
In the Multipathing information section of this output, the numpaths line shows that there are 2 paths to the device, and the following two lines show that the path to c1t0d3 is active (state=enabled) and that the other path c4t1d3 has failed (state=disabled).
The type field is shown for disks on Active/Passive type disk arrays such as the EMC CLARiiON, Hitachi HDS 9200 and 9500, Sun StorEdge 6xxx , and Sun StorEdge T3 array. This field indicates the primary and secondary paths to the disk.
The type field is not displayed for disks on Active/Active type disk arrays such as the EMC Symmetrix, Hitachi HDS 99xx and Sun StorEdge 99xx Series, and IBM ESS Series. Such arrays have no concept of primary and secondary paths.
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