topic Re: Re-setting up a Disk system 2300 in Disk

Re-setting up a Disk system 2300

Marty Metras — Tue, 09 May 2006 14:10:43 GMT

I have a HP disk system 2300 (JBOD) I have 14 drives and they are a mirrored in pairs.
I see we never installed the 2 BCC (Controller). I need to keep data so before I do this I need to do a backup.
I see that drive bays (0-6) are for one bank and (8-14) for the other.
Here is my idea to save some down time. Let me know what you think.
Right now the drives are not mirrored to drives bay on the other bank.
If move that data to the first bank of drives (0-6) then break the mirrors. Install the second BCC then re-create the mirror to bays (0-6) to (8-14). I may minimize my down time.
So I guess what I am asking is, if I add the second BCC after moving the data to the first bank I may not have to restore it from backup. Just re-mirror.
Or, is there another way?

Marty

Re: Re-setting up a Disk system 2300

Steven E. Protter — Tue, 09 May 2006 14:14:10 GMT

Shalom Marty,

Seems like a reasonable plan. Adding a second controller may change the disk device on the attached Unix system.

This may lead to trouble when you try to use he array after this process is complete.

SEP

Re: Re-setting up a Disk system 2300

Marty Metras — Tue, 09 May 2006 14:21:19 GMT

Steven,
Could adding an second BCC make the address of the first one change?
If not could make the address of the 0-6 bay address?
I know it it has to change the hardware address of the new one and bays 8-14 will become 0-6 on the new BCC.

Peace,
Marty

Re: Re-setting up a Disk system 2300

Torsten. — Tue, 09 May 2006 14:47:49 GMT

If you have only 1 BCC there is only one BUS inside the enclosure (full bus mode). You can add now a second BCC (ALWAYS same DIP switch settings) and nothing will change. You have now redundant temperature and voltage monitoring. The first BCC will have SCSI ID 15, the second won't have any ID.

It's advisable to configure split bus mode if you have 2 BCCs for performance reasons. The SCSI IDs will remain, but now you need to use 2 different SCSI HBAs, that means different device files.

The config should be:

HBA1 inside the server, disks in slot 1 to 7 with ID 0 to 6, BCC 15 (BUS1)

HBA2 inside the server, disks in slot 8 to 14 with ID 8 to 14, BCC is 15 (BUS2)

Place terminators on every empty connector.

Re: Re-setting up a Disk system 2300

Marty Metras — Tue, 09 May 2006 14:57:07 GMT

I understand how to hook up the hardware.
When I split the buss which bank will still have the same hardware address, if any?
I am trying to avoid a full restore when I do this.
I have the time to re-create mirrors. It is the down time while I make the change that I am trying to shorten.
Marty

Re: Re-setting up a Disk system 2300

Marty Metras — Tue, 09 May 2006 15:02:25 GMT

Torsten,

Do you mean #7 for bus1 and #15 for bus2?
If I split the buss will 0-7 still be there?
so I can still access the data?
Marty

Re: Re-setting up a Disk system 2300

Torsten. — Tue, 09 May 2006 15:12:52 GMT

Please read again!

I never talked about 0 to 7 anywhere
;-)

ALL IDs will be the same, but if you have 2 busses instead of one, you will have different device files for the disks connected to the second bus.

e.g.

before c1t10d0
after c3t10d0

You can break the mirror and re-mirror or just vgexport/import your VGs without breaking.

Re: Re-setting up a Disk system 2300

Marty Metras — Tue, 09 May 2006 15:14:55 GMT

Ahhh!
Now I understand.

Thanks,
Marty

Re: Re-setting up a Disk system 2300

Torsten. — Tue, 09 May 2006 15:32:14 GMT

Just to add:

a second BCC in a single BUS configuration doesn't make any sense. Even a daisy chained dual bus doesn't.

The only reasonable configuration with 2 BCCs is a split bus in conjunction with 2 separate busses from the host (with different device files for the upper slots).
Just a summary ;-)

Re: Re-setting up a Disk system 2300

Marty Metras — Tue, 09 May 2006 15:39:46 GMT

That was to idea.
Put in the second BCC on another SCSI card so I could mirror these drives the way they should have been in the first place.
It was not setup in the first place because none of us had time or the skill sets to do it right the first time. Now we are smarter, I hope. And we always have time to do things over :-)

Thanks for all you help.
Marty