Veritas Volume Manager -7 [Volume Resize]

                                     

                                               

                       VXVM-7 (Volume Resize)

What we will learn in Next Few Pages,

·         Resize Volumes without Unmount

Resize Volumes Without Unmounting,

#vxassist       it will initiate volume resize with help of

                Growby     / growto

                Shrinkby   / shrinkto

Ok… but there one more step in it, leave it have u remember that in SVM, after resize we need to fire “growfs” b’coz vol mgr knows about the changes but these changes did not directly propagated to File System, so we need to relay that change via “growfs” to File system

Same Here, Vol mgr knows but FS is unaware of changes, and here we need “fsadm”

#vxresize       automatically resizes for both Vol & FS,

root@pr-01:>/# mount -F vxfs /dev/vx/dsk/mydg/myvol /vol-test/

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       200M    23M   166M    13%    /vol-test

root@pr-01:>/# vxassist -g mydg maxsize

Maximum volume size: 5261312 (2569Mb)

This is the free space left in Dg “mydg”

Let’s grow this vol by 50m

root@pr-01:>/# vxassist -g mydg growby myvol 50m

     vxassist   initiator

     -g mydg    DG name

     Growby     expand it

     Myvol      Volume Name

     50m        size to be grown

Let’s check what happened

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       200M    23M   166M    13%    /vol-test

Nothing…

We need to tell the FS also that The Vol has been grown

root@pr-01:>/# fsadm -b 50m /vol-test

UX:vxfs fsadm: INFO: V-3-23586: /dev/vx/rdsk/mydg/myvol is currently 409600 sectors - size will be reduced

Heyyy… what’s the error ?

Why it is telling that size will be reduced

OMG… I did everything correctly, But why it shrink instead to grow

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                        50M    23M    25M    48%    /vol-test

**here I had data less than 50m that’s why still I have those, but what if the data will be larger than 50m?   BOOOM… lost

SO what was wrong in it?

We had given “growby 50m” vxvm thought that this is the new size of the volume and did accordingly,There is no fault of Vol Mgr

We had to use + sign if we want to increase and – for decrease

GOT IT…

Want to try again,

Currently our Vol is of 50m

root@pr-01:>/# vxassist -g mydg growby myvol +50m

root@pr-01:>/# fsadm -b +50m /vol-test

UX:vxfs fsadm: INFO: V-3-25942: /dev/vx/rdsk/mydg/myvol size increased from 102400 sectors to 204800 sectors

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       100M    23M    72M    25%    /vol-test

Now… Fine?

Ok,

root@pr-01:>/# vxassist -g mydg growby myvol +1024m

root@pr-01:>/# fsadm -b +1024m /vol-test

UX:vxfs fsadm: INFO: V-3-25942: /dev/vx/rdsk/mydg/myvol size increased from 204800 sectors to 2301952 sectors

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       1.1G    23M   1.0G     3%    /vol-test

I think it will be clear, Or NOT ?

Let’s reduce…

root@pr-01:>/# vxassist -g mydg shrinkby myvol 500m

VxVM vxassist ERROR V-5-1-7236 Shrinking a FSGEN or RAID5 usage type volume can result in loss of data. It is recommended to use the "vxresize" command or specify "-f" option to force the operation.

root@pr-01:>/# vxassist -f -g mydg shrinkby myvol 500m

root@pr-01:>/# fsadm -b 500m /vol-test/

UX:vxfs fsadm: INFO: V-3-23586: /dev/vx/rdsk/mydg/myvol is currently 2301952 sectors - size will be reduced

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       500M    23M   447M     5%    /vol-test

Great… we did it,

But, Have u noticed that in previous df –kh we have 1.1g and in this we have 500mb, where the 100mb gone?

OHhhh Shit,

I think you are also thinking the same…

That’s why I asked Clear?

Ok... Let’s explain…

What happen when we give the grow/shrink without +/- the vol mgr thinks that this is new size

And when we give +/- vol mgr thinks that this is to add / subtract from what it is currently

NOW ============

Vxresize

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       200M    23M   166M    13%    /vol-test

root@pr-01:>/# vxresize -g mydg myvol +30m

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       230M    23M   194M    11%    /vol-test

root@pr-01:>/# vxresize -g mydg myvol -70m

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       160M    23M   128M    16%    /vol-test

Enough… Now I want to be Tough and should stop playing this +/- game,

OK…

root@pr-01:>/# vxresize -g mydg myvol 300m

root@pr-01:>/# df -kh /vol-test/

Filesystem             size   used  avail capacity  Mounted on

/dev/vx/dsk/mydg/myvol

                       300M    23M   260M     9%    /vol-test

See… no +/