topic Re: RP3410: MSA to Internal Disk/EVA Migration 11.11 in Operating System - HP-UX

RP3410: MSA to Internal Disk/EVA Migration 11.11

nibble — Mon, 25 Jan 2010 12:29:31 GMT

Hi guys,
I have here:

- RP3410 with MSA30
- HPUX11.11
- EVA4400

OS partitions as well as data resides in the MSA30 -- which was previously designed but now, its no longer good due to IO requirements.

Plan: freeup MSA, move the data to the EVA and the OS to the internal disks

With the current limitation of RP3410, it has only 2 pcix slots, which one has been used for the MSA30. I used the last slot for the first single channel HBA. and after the MSA is remove, I will use the other slot for the 2nd HBA for redundancy.

Approach:

1. Insert 2 x internal drives
2. Restore ignite to internal disk
3. Boot up using the internal disk
4. Create luns in EVA and present to 1st HBA
5. Copy or restore DATA to the EVA lun
6. Remove the MSA and the pcix scsi card
7. Present the same lun to the 2nd HBA for multipathing

Question:
1. After step2, how can I assure that OS will boot from internal -- though I know it should be set to primary path.
2. If booted in internal, will there be any conflict booting the OS from the internal disk and the OS partition in MSA is still present?
3. What will be the considerations of presenting the lun first to the first HBA. then add the 2nd HBA sometime later?

Any comments, will be highly appreciated.

Thanks.

Re: RP3410: MSA to Internal Disk/EVA Migration 11.11

Torsten. — Mon, 25 Jan 2010 12:51:39 GMT

1) after ignite restore this becomes the primary path

2) no

3) no problem with this. Without multipathing software, just add the new pathes as PVLINKS

Re: RP3410: MSA to Internal Disk/EVA Migration 11.11

TTr — Mon, 25 Jan 2010 12:51:47 GMT

Your approach is correct. A lot of details are missing but you probably know what needs to be done in each step.

> how can I assure that OS will boot from
internal

The ignite process sets the boot disk path to the disk that is being ingited. You can also verify the path after the OS has booted with "lvlnboot -v". Or interrupt the boot process and ensure the boot device HW path is for the internal disks.

> will there be any conflict booting the OS from the internal
Not at all.
> ...presenting the lun first to the first HBA. then add the 2nd HBA sometime later?
You have to load balance and make the second HBA the primary path for half of the LUNs

Re: RP3410: MSA to Internal Disk/EVA Migration 11.11

nibble — Mon, 25 Jan 2010 17:27:28 GMT

Thanks Guys.

TTR, can you add those missing details please.

Re: RP3410: MSA to Internal Disk/EVA Migration 11.11

TTr — Mon, 25 Jan 2010 18:27:55 GMT

The details are mostly in steps 4, 5 and 7.
In step 4 (and 5), it depends what your LUN structure will look like in the EVA. If it is going to be identical to that of the MSA30, you may be able to add the LUNs to the same volume groups (vgextend) and move the PEs (pvmove) from the MSA30 LUNs to the EVA LUNs. This can be done live without shuting down anything. If the LUNs are going to be different, you probably need to create new volume groups and copy the data over and cut over the mount points to the new LUNs.
In step 7, you will have only one PV path in the volume groups. After you add the second HBA, you need to vgextend the LUNs and add the second PV path to the volume groups. Now the volume groups will have the first EVA path as the primary path and the second EVA path as the alternate. So all your i/o will be coming out of the first HBA.
If you EVA allows, you should make half of the LUN use the second HBA path as the primary LVM path. You vgreduce the first HBA path and the you vgextend the same. (when you vgreduce, the second BHA path will become the primary and when you vgextend the same path back in the volume group it will stay as alternate.) Now half of the LUNs use one HBA for i/o and the other half use the second HBA.

Re: RP3410: MSA to Internal Disk/EVA Migration 11.11

nibble — Wed, 27 Jan 2010 20:44:40 GMT

thanks to all