How to check the free space left in VX DG

How check free space on Veritas diskgroup

In a VxVM environment a diskgroup is a “container” that has different entities ( subdisk , plex , volume ).
When a dg is created an entire disk is referred for this operation.
So , when the free space must be checked , this operation requires a dg control

#vxdg -g dg01 free

DISK DEVICE TAG OFFSET LENGTH FLAGS

oraEU2dg0108 san_vc1_31 san_vc1_31 0 105459840 -

oraEU2dg0108 san_vc1_31 san_vc1_31 202090080 7549840 -

oraEU2dg0117 san_vc1_22 san_vc1_22 104857600 23531040 -

oraEU2dg0117 san_vc1_22 san_vc1_22 191303200 18336720 -

oraEU2dg0127 san_vc1_41 san_vc1_41 104857600 602240 -

oraEU2dg0127 san_vc1_41 san_vc1_41 199831680 9808240 -

#bc

105459840+7549840+23531040+18336720+602240+9808240

165287920

165287920/2

82643960

82643960/1024

80706MB

VxVM Disk Group Total Size

# echo `/usr/sbin/vxprint -g UADG -dF "%publen" | awk 'BEGIN {s = 0} {s += $1} END {print s}'`/2/1024/1024|bc 

Here UADG is diskgroup

How to calculate size of VxVM Disk 

Now we will see how to determine the disk size using vxdisk command.Even though we have many options in OS level to determined that.But let see from veritas level.Once the disk has been brought to veritas control ,VXVM will automatically make public and private region on the disk.By calculating the public region size can determine the disk size. For your information private region size will be always 32MB from VXVM 4.0 on-wards unless until you manually set it while doing vxdisksetup .

Here we go ...

# vxdisk list disk_4 |egrep -i "private|public" |grep -v flags

public:    slice=2 offset=65744 len=143056 disk_offset=48

private:   slice=2 offset=208 len=65536 disk_offset=48

disk_4 = vxvm disk name;

Calculating the disk size:

Disk size in MB (disk_4) = Public region + private region
Public region size = 143056/2/1024 = 69MB
Private region size = 65536/2/1024 = 32MB

Disk Size is 101MB .