SSSU on AIX

[christopher santos_1]

Has anyone did a business copy on AIX using sssu? I just like to get some sample scripts to be used. I'm planning to do snapclone of a volume from aix_server1 then present the snapclone to the same aix_server1.

P.S. This thread has been moved from Disk Array to HP Storage System Scripting Utility (SSSU). -HP Forum Moderator

[Ivan Ferreira]

This is a sample SSSU script:

SELECT MANAGER SWMA1 USER=administrator PASSWORD=administrator
SELECT SYSTEM "EVA1"
DELETE LUN "\Hosts\unix1\10"
DELETE VDISK "\Virtual Disks\data\snap_vdisk1\ACTIVE" WAIT_FOR_COMPLETION

SELECT MANAGER SWMA1 USER=administrator PASSWORD=administrator
SELECT SYSTEM "EVA1"
ADD SNAPSHOT snap_vdisk1 VDISK="\Virtual Disks\data\vdisk1\ACTIVE" DISKGROUP="\Disk Groups\snap"
ADD LUN 1 VDISK="\Virtual Disks\data\snap_vdisk1\ACTIVE" HOST="\Hosts\unix1\10"

The problem that snapshots and snapclones present to IBM AIX is duplicate physical volume identifiers.

The IBM AIX kit includes a utility that will recreate the data on a disk so that it appears as a different disk than the original virtual disk.

To use the snapshot utility, you will need the file /usr/sbin/recreatevg. If your system does not contain this file, you may need to get a newer version of the bos.rte.lvm fileset (4.3.3.75 or later).

You can find the snapshot utility through SMIT in Applications

>Enterprise Virtual Array Snapshots >Recreate Volume Group of a Snapshot.

There are two menu items (each are described in the sections that follow):

- Show Disks with the Same Physical Volume ID
This menu item displays each Enterprise Virtual Array virtual disk and any virtual
disks that have the same physical volume identifier.

- Recreate Volume Group
This menu item allows you to recreate the volume group of a virtual disk that has
the same physical volume identifier as another.

1. Open the snapshot utility and choose Recreate Volume Group.

2. Choose the virtual disk from the list of presented disks.

The utility changes the physical volume ID on the disk, issues the recreatevg command on the disk, and then mounts any filesystems on the disk.

The new volume group name is in the form of sX_, and any of the filesystems are mounted in the directory /snapX.

[Tom O'Toole]

Hi Ivan,

It looks like these smit entries to which you refer are part of HP securepath for IBM, which is used for CAMBEX adapters. I don't have the entries on a system using MPIO and IBM adapters (which has the HP supplied MPIO kit required to use EVA storage).

right now, I'm trying to access a snapshot I presented to this host. I run cfgmgr, as usual, and expect to see the new LUN as a new hdisk, but it doesn't show up (in lspv, lsdev -Cc disk, or any of the /opt/hphsv utilities).

One weird thing that happens is in the cfgmgr -v output, I'm seeing the hdisk of the parent (the one I took the snapshot of) printed twice - from running the fscsi method on ONE adapter only (of the two adapters on the system). I only see the hdisk once on the other adapters output. Anyway, it seems that something in the config piece is seeing the duplicate pvid and refusing to configure it.

Is anybody out there successfully presenting snapshots back to AIX with MPIO? In other words, does anybody know the secret FM handshakes that are required to do this, if it can be done? Thanks.

[Ivan Ferreira]

That is why, even when we have BC, we use Host based clones (by file system features), because more easy to integrate with OS scripts and control the results.

I think the BC is very usefull when you want to present to another host for backup, freeing totally the production host.

[Tom O'Toole]

Thanks Ivan,

Agree that OS controlled snap maybe is easier, and I guess we should look into that, but I'm not sure why it needs to be that way. We are backing up VMS systems using SSSU snapshots every day with few issues or headaches.

I think part of the problem is IBM's LVM/ODM trying to be so self consistent it doesn't allow any virtualization to happen outside its control - even if it's what the user wants. Another problem is most of this stuff is incompletely implemented, and even more incompletely documented (and what documentation is there is scattered and difficult to find (like most things in HP's website)).


Thanks for your comments.

[Ivan Ferreira]

I also agree with you that SSSU scripts should work. But, there is another thing that we don't like too much. We depend of the SMA for SSSU to work, if SMA is not available, snapshots are not created. Here adding another failure variable.

RSM maybe could help if the agent is available for the host OS.

[christopher santos_1]

Hi Ivan,
The information you provided is very useful. But do you have the complete script including the aix host presentation up to the mounting of filesystems?
regards,
chris

[Tom O'Toole]

Does RSM agent actually speak to EVA directly?

[Uwe Zessin]

No, I don't think so. This would require a management ownership transfer. It is my understanding that it is the RSM server that talks to the CV-EVA agent.