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Hello,
My original question was;
> We have a sw230 RAID array with 5xrz28 for
> 8GB raid capacity on an Alphaserver 2100 4/200 . We are using
> the internal sw array for the raid. all 5 disks are configured
> as 1 disk group. The raid array is our only file system, other
> than a swap disk; ie its has /root as well as /usr mounted on it.
>
> We wish to add 2 more disks to take us up to our 12GB Maximum
> (with rz28's). I am fairly sure that to do this I need to;
>
> 1:) back the system up
> 2:) back it up again
> 3:) check the back ups
> 4:) if paranoid back up with another tool ( tar instead of dump)
> 5:) check the paraniod backup
> 6:) take the system down
> 7:) add the disks
> 8:) boot arc
> 9:) run the raid config utility from floppy
> 10:) rebuild the new raid array
> 11:) boot from the CDROM
> 12:) make a new file system
> 13:) restore from tape
>
> My boss seems to to think that I should be able to just
> add the disks without having to reconfigure the raid array, and
> destroy the information currently on the system. I can't see
> how this can happen.
>
> Am I wrong ?
Thanks for your replys, its as I thought you can't just tack
the extra disks on.
Arun Sanghvi and Ed Bailey asked about having the os on the raid,
Arun said that DEC had advised them not to do this, I wish DEC had
advised us not to go that way, but they didn't. If I was beginning
again I would certainly not do this. Maybe I'll change when we add
the disks. Ed's setup seems an excellent way to go.
Thanks to:
System Janitor <hubcap_at_hubcap.clemson.edu>
sanghvi_at_proto.wilm.ge.com (arun sanghvi)
Bugs Brouillard <bb1_at_axe.humboldt.edu>
"Edward C. Bailey" <ed_at_pigdog.niehs.nih.gov>
alan_at_nabeth.cxo.dec.com (Alan Rollow - Dr. File System's Home for Wayward Inodes.)
"Dave Golden" <golden_at_falcon.invincible.com>
The replys
--------------------------------------------------------------
From: System Janitor <hubcap_at_hubcap.clemson.edu>
I expect you are right and your boss is wrong. You can't
just jam on two more disks that the controller doesn't
know about and expect it to work.
You could add them on and configure them in as JBOD without
messing up the current RAID array, but if you want to add them
into the RAID array, I believe you will have to do as you
said... back the whole thing up, go through the controller
configuration (including initialization of the array, which will
wipe it out), and restore.
-Mike
-----------------------------------------------------------------
From: sanghvi_at_proto.wilm.ge.com (arun sanghvi)
Brian,
Your procedure seems correct. We were told by DEC that not to
use RAID drive for operating system.
Arun Sanghvi
GE-NF&CM
-----------------------------------------------------------------
From: Bugs Brouillard <bb1_at_axe.humboldt.edu>
You are right, your boss is fataly wrong!!!!
Bugs Brouillard Unix system administrator
Humboldt State Univ. 707-826-6123
Arcata, Calif Fax 707-826-6100
email bb1_at_axe.humboldt.edu
-----------------------------------------------------------------
From: "Edward C. Bailey" <ed_at_pigdog.niehs.nih.gov>
>>>>> "Brian" == "Brian James O'Connor" <boc_at_ironbark.bendigo.latrobe.edu.au> writes:
[snip]
Brian> We wish to add 2 more disks to take us up to our 12GB Maximum (with
Brian> rz28's). I am fairly sure that to do this I need to;
Brian> 1:) back the system up 2:) back it up again 3:) check the back ups
Brian> 4:) if paranoid back up with another tool ( tar instead of dump) 5:)
Brian> check the paraniod backup 6:) take the system down 7:) add the disks
Brian> 8:) boot arc 9:) run the raid config utility from floppy 10:)
Brian> rebuild the new raid array 11:) boot from the CDROM 12:) make a new
Brian> file system 13:) restore from tape
That sounds about right to me, but you don't have enough backup
steps... ;-)
Brian> My boss seems to to think that I should be able to just add the
Brian> disks without having to reconfigure the raid array, and destroy the
Brian> information currently on the system. I can't see how this can
Brian> happen.
Your boss proves once again that management should be separate from system
administration... :-) Nothing against your boss, but he/she is mistaken.
In the RAID config utility, you'll need to delete the current drive group,
create a new one consisting of your present drive and the two new ones,
create a new logical drive, initialize it, and exit. Then exit the RCU,
boot off CD, create a new filesystem, and do your restores...
By the way, how do you find the performance of having your operating system
on a RAID 5 array? We normally put six drives in a shelf (so we can have
redundant power supplies), and mirror the first two for the O/S, and RAID 5
the rest...
Ed
--
Ed Bailey, Information Systems and Networks
(contracted to: National Institute of Environmental Health Sciences)
2327 Englert Drive.
Suite 200
Durham, NC 27713
Internet: bailey_at_niehs.nih.gov
BITnet: BAILEY_at_NIEHS.BITNET
Voice: (919)361-9422, extension 239
FAX: (919)544-6642
-----------------------------------------------------------------
From: alan_at_nabeth.cxo.dec.com (Alan Rollow - Dr. File System's Home for Wayward Inodes.)
You should be able to add disks to the subsystem as another RAID
(stripe set or mirror) or just as disks without perturbing the
existing RAID-5. But, you can't increase the size of the
existing RAID without backing up and restoreing the existing
data.
-----------------------------------------------------------------
From: "Dave Golden" <golden_at_falcon.invincible.com>
You are correct. Your only alternative would be to create a new
RAID array with a new filesystem, or if you are using AdvFS, you
could add a new array to the usr_domain.
Dave
--
Dave Golden golden_at_invincible.com
Invincible Technologies Corporation
-----------------------------------------------------------------
Thanks again
boc
------------------------------------------------------------
Brian O'Connor, Unix Systems Consultant
Latrobe University,Bendigo
boc_at_ironbark.bendigo.latrobe.edu.au
------------------------------------------------------------
Received on Tue Aug 27 1996 - 01:23:47 NZST