Question about LVM/JFS versions

[Dave Johnson_1]

I have 3 IA-64 computers running HP-UX 11.23 (0609) and B3929DA ver B.11.23.06.09, 4 PA-RISC running 11.11 (0612) and B3929DA ver 3.5-ga15-04 and 2 PA-RISC 11.11 (0412) and running B3929CA ver B.11.11.03.03 of the OnLineJFS product. The version 3.5-ga15-04 reports as version 3.5, the others do not specify.
I want to move a couple of LUNs in an active file system to different LUNs so I can rebuild the RAID-Array pack they are sitting on. I would be moving from 7GB LUNs to 7GB LUNs in the same XP512 disk array.
I read at some time in the past that the older version of OnLineJFS did not allow me to move LUNs in a vg while the file system is mounted and Oracle is accessing it, but a newer version did and I thought that new version was 3.5.
1. Is that statement true?
2. Does version 3.5 give that ability?
3. Is there a newer version I should consider?
4. What do I need to do to upgrade an older version file system to the newer version of JFS?

[Jeeshan]

LUN moving should be performed from SAN. It's a better practice.

[Duncan Edmonstone]

Dave,

>I read at some time in the past that the older version of OnLineJFS did not allow me to move LUNs in a vg while the file system is mounted and Oracle is accessing it,

If I'm understanding what you want to do correctly, this has nothing to do with the filesystem (JFS) and everything to do with LVM.

Never mind all the version info you provided, can you explain a little more what you mean here? You seem to be saying you are going to un-present some LUNs that are part of a VG with filesystems on it, and then present new equivalent LUNs from somewhere else... the *only* way to handle that online would be to add those new LUNs into the VG first and then use the LVM pvmove command to migrate the data off the old LUNs to the new LUNs before unpresenting the old LUNs. The constraint here is whether your VG limits will allow you to add all the new LUNs into the VG - you've already said you would be adding in new LUNs of the same size as the old ones, so you don't need to be concerned about the max PE per PV limit but for this you will need to look at Cur PV and Max PV values to make sure you can add LUNs to the VG.

So assuming you can do all this the taksks are basically:

i) Present new LUNs to server - use ioscan and insf to create device files
ii) pvcreate new LUNs and add into volume group with vgextend
iii) use the pvmove command to relocate extents off the old LUNs onto the new LUNs
iv) once you are happy all extents are moved off the old LUNs you can vgreduce them out of the VG
v) Once out of the VG you can un-present the LUNs from the host.

That's simplifying it a bit, and as I said you may have constraints around your current VG limits, or also around how you use the VGs (e.g. if you use distributed extent based striping), but this can work if the constraints are satisfied regardless of the filesystem running on the logical volumes

HTH

Duncan

[likid0]

Just to add to Duncan post, i would add, that if you have MirrorDisk/UX bundle, I prefer to mirror the lvols rather than using pvmove, it's safer.

the way to go is the same:

1.Add the new disk to the vg
2.check the lvols that use the old disk:
pvdisplay -v oldisk

3.for each lvol do:

lvextend -m 1 /dev/vg/lvol newdisk

4. for each lvol do:

lvexetnd -m 0 /dev/vg/lvol olddisk

5. check your old disk has no pes in use:
pvdisplay -v oldisk

6. take the old disk out of the vg:

vgreduce /dev/vg olddisk

[Dave Johnson_1]

Thanks for the comments.
1. As far as I know my XP512 does not have the ability to move a LUN for me.
2. I am using MirrorDisk/UX and I have my lvols set with striping. PVMOVE uses mirroring to perform the move. The older version of JFS does not allow striping and mirroring. I was under the impression the "newer" version did which would allow me to use PVMOVE to move the LUN.
So back to my original question, which version of JFS allows striping and mirroring so I will be able to use PVMOVE to move the LUN?

[Duncan Edmonstone]

Dave,

You're getting slightly confused here - JFS is the filesystem and has nothing to do with striping an mirroring. It's LVM that provides the striping and mirroring capability.

You are correct in that LVM in 11.11 support striping -or- mirroring on a logical volume but not both (although you were always able to get around this using extent based striping - are you sure you're not using that?)

On 11.23 if you have the correct patches installed (PHKL_36745 and PHCO_38717) then LVM does support striping and mirroring and its also supported on 11.31 (although you don't mention that you have that OS).

However I've never tried a pvmove or lvextend -m ... on a striped LV so, am not toally sure what the outcome would be.

HTH

Duncan

[Dave Johnson_1]

Sorry for the misstatement about JFS and LVM, I tend to think of the as the same thing.
I had tried to do a pvmove in the past and was told by LVM that striping and mirroring is not allowed.
So does anyone know which version of LVM allows striping and mirroring?

[Duncan Edmonstone · Accepted solution]

yes as I said - the version in HP-UX11.23 will do if the patches I mentioned are applied, as will the version in HP-UX11.31.

For 11.11 there is *no* version that supports this, nor will there be.

HTH

Duncan

[Dave Johnson_1]

Thanks Duncan. The bummer is, the server I really need to move the LUNs on is running 11.11 (0412) on PA-RISC.
So to get where I need to be, I will have to do an OS upgrade first.
The HP-UX Wiki says the Sept 2004 version of 11.23 runs on PA-RISC. Is that correct?

[Duncan Edmonstone]

Yes the Sep 04 and later versions of 11iv2 run on PA-RISC. Get the absolute latest set of DVDs you can though.

Again I must emphasise - just cos 11.23 supports striped mirrors doesn't mean that I've seen someone succesfully do what you are attempting (although it makes sense to me that this should work) - so if there's a way to test it first on your system thats already at 11.23 that would be better...

HTH

Duncan