pvmove - striped volumes - Does it work? confused.

[Filipe_1]

Greetings forumers;

For performance reasons, we have to replace some disks on a VG. These disks to be replaced are quite the same type of the new disks, same size, etc.

The question is: The volumes on this VG were created as striped, as I think it is the default behavior.

The man page is OK about the procedure, as the course student workbook. We never perforemed it before.

But... this thread disturbed us. http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=231727

Neither the man page and the couse mentions that we can't pvmove disks with stripped LV data on IT.

Can someone clarify us?

Will assign points.

Rgds,

Filipe.

[Pete Randall]

Filipe,

If Dietmar says pvmove doesn't support stripes, I would take it as fact. Unless something has changed since Dietmar made that response (and I don't think it has), I would have to say that you can't do it.


Pete

[Pete Randall]

Here is some further clarification:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=575520


Pete

[Alzhy · Accepted solution]

Well.. it's one of those weakness(es) of LVM yet again. With VxVM... you will not have this limitation as the equivalent command "vxevac" does not care how VOLs are organised when moving extents from one disk to another (do a man on vxevac on any 11i system).

I guess your only choice is to do cold moves via dd or vxdump/vxrestore.

[Sanjay_6]

Hi,

You cannot do pvmove on a striped lv.

You can creae a new volume and then use dd to move the data to a new disk.

Hope this helps.

regds

[Filipe_1]

Thanks for the prompt response, folks.

I am still in doubt.

"NOTE: pvmove cannot be used with kbyte based striped logical volumes, those
created with lvcreate -i -I )."

Then.. I can move if it is NOT kbyse based logical volume. OK.

The lvdisplay says my volume is striped. Sorry my lack of knowledge of LVM, but how can I be certain of what kind of stripe I have?

Here is an example of my volumes.

LV Name /dev/vg01/lv_oracle
VG Name /dev/vg01
LV Permission read/write
LV Status available/syncd
Mirror copies 0
Consistency Recovery MWC
Schedule striped
LV Size (Mbytes) 5000
Current LE 1250
Allocated PE 1250
Stripes 2
Stripe Size (Kbytes) 4
Bad block on
Allocation strict
IO Timeout (Seconds) default

--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/dsk/c9t1d7 625 625
/dev/dsk/c8t5d4 625 625

--- Logical extents ---
LE PV1 PE1 Status 1
0000 /dev/dsk/c9t1d7 0000 current
0001 /dev/dsk/c8t5d4 0000 current
0002 /dev/dsk/c9t1d7 0001 current
0003 /dev/dsk/c8t5d4 0001 current
0004 /dev/dsk/c9t1d7 0002 current
0005 /dev/dsk/c8t5d4 0002 current
0006 /dev/dsk/c9t1d7 0003 current
0007 /dev/dsk/c8t5d4 0003 current
0008 /dev/dsk/c9t1d7 0004 current
0009 /dev/dsk/c8t5d4 0004 current
(...)

[Pete Randall]

Just try it. As Bernhar Mueller states in the thread I pointed you to,

"this is what you would see tring to pvmove:

pvmove /dev/dsk/c4t2d3 /dev/dsk/c4t2d5
Operation cannot be performed because some of the data on the physical volume
is striped and striped mirroring is not supported. To enable data transfer for
a physical volume through mirroring/reduction, do not specify the striping
options (-i, -I) when creating logical volumes on that physical volume."

So try it - if it fails, you'll know you can't.


Pete