Has anyone used Clariion LUN Migrate function on-line?

Folks,

I need to build a 400 GB LUN for a snap clone BCV cycle.

My Clariion is nearly full so I did some space reclamation
and now I have 300 GB, 200 GB and 185 GB free in 3
separate RAID Groups. Happy Murphy's Law that none
of the freed LUNs were in the same RAID Group.

I know how to right-click on a LUN, select Migrate, and
move the data on-line to another RAID Group. The problem
is they all have mounted file systems and I've never used
the function before. In the past I've done migrations at
the LVM layer using Veritas or whatever. I would really
like a warm fuzzy before running it even though the docs
all claim it works great.

Thanks in advance!

Hi Doug,

Tell me the Luns which you are migrating are on which operating
systems..

For windows , If Migrating Lun is being formatted in OS as
dynamic ,then there isnt any problem in extending the drive online.

For AIX u can basically have to use extendfs for the slice to extend.

For HP , it will only extend online, if u have jfs installed on ur HP
Box.


On Jun 1, 3:34 am, Doug Freyburger wrote:
Folks,

I need to build a 400 GB LUN for a snap clone BCV cycle.

My Clariion is nearly full so I did some space reclamation
and now I have 300 GB, 200 GB and 185 GB free in 3
separate RAID Groups. Happy Murphy's Law that none
of the freed LUNs were in the same RAID Group.

I know how to right-click on a LUN, select Migrate, and
move the data on-line to another RAID Group. The problem
is they all have mounted file systems and I've never used
the function before. In the past I've done migrations at
the LVM layer using Veritas or whatever. I would really
like a warm fuzzy before running it even though the docs
all claim it works great.

Thanks in advance!

vipmishal wrote:
Doug Freyburger wrote:

I need to build a 400 GB LUN for a snap clone BCV cycle.

My Clariion is nearly full so I did some space reclamation
and now I have 300 GB, 200 GB and 185 GB free in 3
separate RAID Groups. Happy Murphy's Law that none
of the freed LUNs were in the same RAID Group.

I know how to right-click on a LUN, select Migrate, and
move the data on-line to another RAID Group. The problem
is they all have mounted file systems and I've never used
the function before. In the past I've done migrations at
the LVM layer using Veritas or whatever. I would really
like a warm fuzzy before running it even though the docs
all claim it works great.

Tell me the Luns which you are migrating are on which operating
systems..

If the function works as advertised then the OS should not
matter. It should be transparent to a running OS. But since
I have not used that function I'm paranoid. Asking around
I've gotten one response from someone who did it in a lab
setting not on a running server.

For HP , it will only extend online, if u have jfs installed on ur HP
Box.

The existing LUN has an HPUX volume group, logical volume,
mount point on it. No expansion involved though. It should move
the existing LUN from one RAID Group to another with no
effect at all on the data, LUN number, WWN and so on.
"Should" is just one of those words.

I've done plenty of lower-case-m migrations from array to
array using LVM layer, filesystem migrations using tar
and so on, array layer using SRDF. but all of those involve
a new LUN number ...

I've used the migrate LUN feature to move Windows LUNs with no
problems at all - it is completely transparent however the normal
caveats apply - backup your data, schedule the migration during a
quiet time etc.


I've not done this for an HP-UX system so can't comment but HP-UX is
sensitive to any change in LUN presentation including the LUN id from
my experience.

There is some confusion in this thread about expanding vs migrating.
Migrating a LUN involves moving a LUN to a completely different array
and *should* be completely transparent to the host, whereas expanding
a LUN implies a meta-LUN using the exisitng LUN as a base and requires
OS interaction. Of course you could migrate and expand the LUN at the
same time if you use the LUN migration feature to migrate to a bigger
LUN....

Jono968 wrote:

I've used the migrate LUN feature to move Windows LUNs with no
problems at all - it is completely transparent however the normal
caveats apply - backup your data, schedule the migration during a
quiet time etc.

Thanks.

I've not done this for an HP-UX system so can't comment but HP-UX is
sensitive to any change in LUN presentation including the LUN id from
my experience.

That and Clariions tend to be flakey in my experience.

There is some confusion in this thread about expanding vs migrating.
Migrating a LUN involves moving a LUN to a completely different array

Within a single array not among arrays.

and *should* be completely transparent to the host, whereas expanding

Moving from array to array would move a LUN into another SAN
login session and another switch port. There's no way that can be
made transparent for all cases.

That's why lower-case-m migration isn't upper-case-M Migration.

a LUN implies a meta-LUN using the exisitng LUN as a base and requires
OS interaction. Of course you could migrate and expand the LUN at the
same time if you use the LUN migration feature to migrate to a bigger
LUN....

It only offers LUNs that are exactly the same number of bytes. Same
as
adding to a snap clone group.

Hi Doug,

I've done this multiple times on windows, solaris, and AIX. Never had
any problems. Host wont even know whats happened. If you need to spill
into production hours due to LUN size, just throttle back the migration
speed. Shouldn't be a problem at all.

-Anthony

Doug Freyburger wrote:
Folks,

I need to build a 400 GB LUN for a snap clone BCV cycle.

My Clariion is nearly full so I did some space reclamation
and now I have 300 GB, 200 GB and 185 GB free in 3
separate RAID Groups. Happy Murphy's Law that none
of the freed LUNs were in the same RAID Group.

I know how to right-click on a LUN, select Migrate, and
move the data on-line to another RAID Group. The problem
is they all have mounted file systems and I've never used
the function before. In the past I've done migrations at
the LVM layer using Veritas or whatever. I would really
like a warm fuzzy before running it even though the docs
all claim it works great.

Thanks in advance!