Richard,
VDISK sounds like a new direction for our system too. Thanks.
Mary
Schuh, Richard wrote:
Mary,
If you have sufficient paging space, you might consider using V-disk instead of
T-disk. As Nick pointed out, they are not subject to fragmentation and the
limits for the individual users and the system as a whole can be set and
adjusted dynamically. If you are not already paging constrained and you have
the space, it might be a way out of the fragmentation problem. Look under HELP
CP DEFINE (RELATED and select VDISK. You may also need to set limits using SET
VDISK.
We have been using V-disk in place of T-disk for the past several years and
have never had a problem with it.
-----Original Message-----
From: VM/ESA and z/VM Discussions [mailto:[EMAIL PROTECTED] On Behalf Of
Mary Zervos
Sent: Tuesday, January 24, 2006 6:43 AM
To: [email protected]
Subject: Re: Tdisk question
Thanks Jim for the insight. I had forgotten about fragmentation.
Mary
Jim Bohnsack wrote:
Mary--What you're seeing is fragmentation. TDISK is allocated in one
whole piece to a user. Think of PC disk allocation that you see when
you run a defrag. If you have 1 allocated cylinder out in the middle
of an otherwise empty 100 cylinder TDISK space, you cannot allocate a
99 cyl TDISK. You would get that by the first user getting 50
cylinders and the 2nd user getting 1 cylinder. When the first user
detaches the 50 cyl. disk, the 2nd user still has the 1 cyl in the
middle. You are left with 99 cylnders in total free but you can only
allocate a max of 50 cylinders and 49 cylinders.
Jim
At 09:17 AM 1/24/2006, you wrote:
I have 500 cyl. of tdisk defined on one pack and 50 cyl. of tdisk
defined on another. One user used the 50 cyl. on the second pack
and about 24 users have used 215 cyl.(43%used) on the first pack.
Why is it that I can only allocate a 130 cyl. maximum tdisk on the
first pack but can then go ahead and allocate a 110 cyl. tdisk,
instead of being able to allocate *one* 240 cyl. tdisk?
Thanks for any help.
Mary Zervos
VM Systems Programmer
Binghamton University
[EMAIL PROTECTED]
Jim Bohnsack
Cornell Univ.
(607) 255-1760
