From: mattr@awesome.csd.sgi.com (Matt Robinson)
Subject: Re: logical volumes
Keywords: lv logical volume
Organization:  Silicon Graphics, Inc.  Mountain View, CA
Date: Wed, 13 Jan 1993 04:56:41 GMT

In <1993Jan12.185353.11673@dsea.com> lacey@dsea.com (Dan Lacey ) writes:
] I am trying to use the logical volume feature on an R4K Indigo.
] ( And what a great idea it is!! )
] I have two questions: 
]	1) What is the largest possible logical volume and how many partitions
]	can this consist of.

8 gigabytes is the largest EFS size.  According to what I've found in the
code here, the maximum number of logical volume partitions that can be
specified in /etc/lvtab is 40.

] 	2) Am i doing the right thing ( as explained below). I seem to have
] 	gotten the right result, but I am paranoid about having missed
] 	something. Also, besides the on-line UNIX manuals, where can I find
] 	documentation about this feature?

The documentation should be in the Site Administration Guide, as well as
the Insight product.

BEFORE YOU GO ON:  Make sure to backup your system.  I didn't read anywhere
up there that you had decided to backup your system.  It is *always* important
to backup before making any partition / file system changes.

] I have a 1.2Gb disk on the R4k Indigo that was partitioned as a rootdrive.
] I install 4.0.5F (default parts) on the rootdrive.
] I partitioned the second disk as an option drive and run mkfs. (SCSI ID 3)

Did you write the label to the disk (e.g., enter the '(l)abel' section, then
select '(sy)nc'?) If you perform a 'prtvtoc /dev/rdsk/dks0d3vh', you can
see the label on the disk, and the partitioning information.  Make sure it
is correct before continuing.

] I want to have the /usr partition be a logical volume.
]
] I edit lvtab with the entry:
] lv0:usr:devs=/dev/dsk/dks0d1s6, /dev/dsk/dks0d3s7
]
] I edit the /usr entry in fstab:
] /dev/dsk/lv0 /usr efs rw,raw=/dev/rdsk/lv0 0 0

This looks okay, since you stated above that the SCSI ID of your option
drive was 3.

] Go to single user mode to unmount /usr.
]
] Make the volume. I need the -f because mklv is complaining that the second
] disk does not have a label ( <NO LABEL PRESENT> ).
] # mklv -f lv0

At this point, run 'lvck', to check over your logical volume creation.
You should get the message:

lvck: checking lvtab entry lv0
lvck: entry lv0 OK

or something very close to that.  If this doesn't come up, something's
wrong with the logical volume you've created.

] Grow the filesystem:
] # growfs /dev/rdsk/lv0

After the above step, make sure to:

fsck /dev/rdsk/lv0
mount /usr

This will check over the disk (shouldn't be necessary), then mount it.

] Bring the system up:
] # init 2

After this point, bring up the system.  Everything should run smoothly.

] THANX IN ADVANCE

If you have problems, please give the individuals on the hotline a call,
or E-mail me your question on this specific case if need be.

] 					Dan Lacey
] 					lacey@dsea.com
] 					Dainippon Screen Eng. of America

--Matt

---------------------------------------------+-------------------------------
Matt D. Robinson (Member, Technical Staff)   |      mattr@awesome.csd.sgi.com
Silicon Graphics, Inc.                       |      mattr@leland.stanford.edu
--
---------------------------------------------+-------------------------------
Matt D. Robinson (Member, Technical Staff)   |      mattr@awesome.csd.sgi.com
Silicon Graphics, Inc.                       |      mattr@leland.stanford.edu