Description

When a device is under Volume Manager control, the format is usually either sliced, or cdsdisk.
 

Sliced devices

The sliced format can be applied to disks that can be used to boot the system. If the disk is not initialized as a boot disk, space is reserved on the disk to allow it to be converted to the cdsdisk format, if required. For sliced devices, the public, and private, regions are located on separate slices 4, and 3, respectively, by default. This can be changed during initialization.

Example of initializing a sliced device:

# /etc/vx//bin/vxdisksetup -i c1t8d0 format=sliced

# vxdisk list c1t8d0s2
Device:    c1t8d0s2
devicetag: c1t8d0
type:      auto
hostid:    ms1
disk:      name=t8 id=1266597187.43.ms1
group:     name=slicedg id=1266597358.55.ms1
info:      format=sliced,privoffset=1,pubslice=4,privslice=3
flags:     online ready private autoconfig autoimport imported
pubpaths:  block=/dev/vx/dmp/c1t8d0s4 char=/dev/vx/rdmp/c1t8d0s4
privpaths: block=/dev/vx/dmp/c1t8d0s3 char=/dev/vx/rdmp/c1t8d0s3
guid:      -
udid:      FUJITSU%5FMAG3182L%20SUN18G%5FDISKS%5F00540782%20%20%20%20
site:      -
version:   2.1
iosize:    min=512 (bytes) max=2048 (blocks)
public:    slice=4 offset=0 len=35358848 disk_offset=9424
private:   slice=3 offset=1 len=4455 disk_offset=4712
update:    time=1291661988 seqno=0.15
ssb:       actual_seqno=0.0
headers:   0 248
configs:   count=1 len=3259
logs:      count=1 len=493
Defined regions:
 config   priv 000017-000247[000231]: copy=01 offset=000000 enabled
 config   priv 000249-003276[003028]: copy=01 offset=000231 enabled
 log      priv 003277-003769[000493]: copy=01 offset=000000 enabled
Multipathing information:
numpaths:   1
c1t8d0s2        state=enabled

When using the prtvtoc command, the value in the Tag column indicates the type of partition.

In this example, a sliced device has slice 3 with tag 15 (specifying a private region), and slice 4 with tag 14 (specifying a public region).
Note: Slice 2 should always have a tag of 5, and span the entire device.

# prtvtoc /dev/rdsk/c1t8d0s2
* /dev/rdsk/c1t8d0s2 partition map
*
* Dimensions:
*     512 bytes/sector
*     248 sectors/track
*      19 tracks/cylinder
*    4712 sectors/cylinder
*    7508 cylinders
*    7506 accessible cylinders
*
* Flags:
*   1: unmountable
*  10: read-only
*
* Unallocated space:
*       First     Sector    Last
*       Sector     Count    Sector
*           0      4712      4711
*
*                          First     Sector    Last
* Partition  Tag  Flags    Sector     Count    Sector  Mount Directory
       2      5    01          0  35368272  35368271
       3     15    01       4712      4712      9423
       4     14    01       9424  35358848  35368271
 

 

cdsdisk devices

A disk that is formatted as a CDS disk is suitable for moving between different operating systems. This is the default format for most disks, but it is not suitable for boot disks.
Note: As the CDS format is applied to the entire disk, and is unsuitable for boot disks, attributes that relate to slices, or to booting, are not applicable.

In this example, notice that slice 2 is being shown as the public, and private region. This is due to the device being a cdsdisk type to allow for cross platform imports. Slice 2 should always have a tag of 5, and span the entire device.

The vxdisksetup command used to initialize this cdsdisk device (cdsdisk is default):

# /etc/vx//bin/vxdisksetup -i c1t8d0
# vxdisk list c1t0d0s2
Device:    c1t0d0s2
devicetag: c1t0d0
type:      auto
hostid:    ms1
disk:      name=t0 id=1266596976.21.ms1
group:     name=cdsdg id=1266597139.41.ms1
info:      format=cdsdisk,privoffset=256,pubslice=2,privslice=2
flags:     online ready private autoconfig noautoimport imported
pubpaths:  block=/dev/vx/dmp/c1t0d0s2 char=/dev/vx/rdmp/c1t0d0s2
guid:      {f753cbc2-1dd1-11b2-81e6-0003bad88c3e}
udid:      SEAGATE%5FST39102LCSUN9.0G%5FDISKS%5F393933305932353836340000
site:      -
version:   3.1
iosize:    min=512 (bytes) max=2048 (blocks)
public:    slice=2 offset=2304 len=17679776 disk_offset=0
private:   slice=2 offset=256 len=2048 disk_offset=0
update:    time=1291664243 seqno=0.60
ssb:       actual_seqno=0.0
headers:   0 240
configs:   count=1 len=1280
logs:      count=1 len=192
Defined regions:
config   priv 000048-000239[000192]: copy=01 offset=000000 enabled
config   priv 000256-001343[001088]: copy=01 offset=000192 enabled
log      priv 001344-001535[000192]: copy=01 offset=000000 enabled
lockrgn  priv 001536-001679[000144]: part=00 offset=000000
Multipathing information:
numpaths:   1
c1t0d0s2        state=enabled

In this example, the prtvtoc output for a cdsdisk disk has slice 7, with a tag of 15, and spans the entire device.

# prtvtoc /dev/rdsk/c1t0d0s2
* /dev/rdsk/c1t0d0s2 partition map
*
* Dimensions:
*     512 bytes/sector
*     133 sectors/track
*      27 tracks/cylinder
*    3591 sectors/cylinder
*    4926 cylinders
*    4924 accessible cylinders
*
* Flags:
*   1: unmountable
*  10: read-only
*
*                          First     Sector    Last
* Partition  Tag  Flags    Sector     Count    Sector  Mount Directory
       2      5    01          0  17682084  17682083
       7     15    01          0  17682084  17682083

 

Common partition tags

Name	Number
UNASSIGNED	0x00
BOOT	0x01
ROOT	0x02
SWAP	0x03
USR	0x04
BACKUP	0x05
STAND	0x06
VAR	0x07
HOME	0x08

 

The value in the Flags column indicates how the partition is to be mounted. This value is not regarded by the mount command.

MOUNTABLE,READ AND WRITE	0x00
NOT MOUNTABLE	0x01
MOUNTABLE,READ ONLY	0x10

How to interpret the prtvtoc output for sliced and cdsdisk devices