Is there any way to tell AIX that a disk size has changed, as what
happens when you add say 100Gig to the same partition on a SAN?

I am from old school, where adding space means adding a new disk and
then adding it to the volume group. But SAN space has been added for me
as if I can expand the current disk size. Is this possible for me to do?

So, you are saying the the SAN volume was increased in size on the fly?
I assume your SAN is something like an ESS 800 or similar? I've not
tried that before, would be interesting to hear how that goes...


ckgeier@juno.com wrote:

> Is there any way to tell AIX that a disk size has changed, as what
> happens when you add say 100Gig to the same partition on a SAN?
>
> I am from old school, where adding space means adding a new disk and
> then adding it to the volume group. But SAN space has been added for me
> as if I can expand the current disk size. Is this possible for me to do?

try chvg -g VG_NAME

we use it with SAN Volume Controller.
Don't know whether it works with FastT or ESS.

Andy


On 17 Oct 2005 13:58:42 -0700, ckgeier@juno.com wrote:

>Is there any way to tell AIX that a disk size has changed, as what
>happens when you add say 100Gig to the same partition on a SAN?
>
>I am from old school, where adding space means adding a new disk and
>then adding it to the volume group. But SAN space has been added for me
>as if I can expand the current disk size. Is this possible for me to do?


--
Andreas Beckmann
Andreas.Beckmann@muenster.de
http://www.muenster.de/~andy

ckgeier@juno.com wrote:
> Is there any way to tell AIX that a disk size has changed, as what
> happens when you add say 100Gig to the same partition on a SAN?
>
> I am from old school, where adding space means adding a new disk and
> then adding it to the volume group. But SAN space has been added for me
> as if I can expand the current disk size. Is this possible for me to do?
>
Nope... if you change the PV size you will need to restore your data.
However you can create a new PV and add it to the VG.

--
BC

depends... DVE as dynamic volume expansion has been supported on
various storages, AIX supports it thru re-reading the disk info thru
chvg -g <volume group>...
the operation is not true dynamic, since you have to stop I/O to the
disk you're trying to extend ( meaning, on AIX side you'll need to stop
applications, unmount all file systems and varyoff volume group prior
changes )

ckgeier@juno.com wrote:
> Is there any way to tell AIX that a disk size has changed, as what
> happens when you add say 100Gig to the same partition on a SAN?
>
> I am from old school, where adding space means adding a new disk and
> then adding it to the volume group. But SAN space has been added for me
> as if I can expand the current disk size. Is this possible for me to do?
>
You didn't state your AIX version, but the extract from the AIX 5.2
Redbook SG245765 section 4.2.11 goes like this:

========

For example, to increase the size of a LUN in a FAStT 500 storage
subsystemand make AIX aware of this change, the following steps need to
be performed:

1. Change the size of the LUN in the FAStT 500 storage subsystem.

2. Unmount all file systems in the affected volume group for every file
systemusing the following command:

umount /filesystem

3. Vary off the volume group, using the following command:

varyoffvg vgname

4. Vary on the volume group, using the following command:

varyonvg vgname

5. Mount all the file systems unmounted in step 2, using the following
command:

mount /filesystem

6. Add the new PPs to the volume group using the following command:

chvg -g vgname

The growing of disks in the rootvg and in activated concurrent VGs is
not supported. The change of the chvg command is reflected in Web-based
System Manager.

========

HTH,
Andy.

vlad.zam@gmail.com wrote:
> depends... DVE as dynamic volume expansion has been supported on
> various storages, AIX supports it thru re-reading the disk info thru
> chvg -g <volume group>...
> the operation is not true dynamic, since you have to stop I/O to the
> disk you're trying to extend ( meaning, on AIX side you'll need to stop
> applications, unmount all file systems and varyoff volume group prior
> changes )
>

Yes... you are right and I was wrong. I wasn't aware of this new (2/3
years!) feature!
And please be aware that it's not supported on rootvg disks.
--
BC