VOLUTIL will not allow you to configure permanent space on LDEV 1 at 100%.
This is a convention dating back forever, (at least to the early days of
MPE/XL) to assure that at least 25% of LDEV 1 is available for bootable
transient space.  As disk sizes grew, and because LDEV1 is now supported up
to 4 GB in size, you can probably make the permanent space allocation
somewhat higher than 75% on larger drives, but I don't see this often
recommended.  You may certainly increase the allocation percentages on your
new device to 100/100, if you wish, and you can do it 'on the fly'.  The
original push release of 5.0 (IIRC) introduced a change (bug?) to the
algorithms used to keep the disks balanced, if fewer than five (5) volumes
were in use in the MPEXL_SYSTEM_VOLUME_SET.  This caused more permanent
file extents to reside on LDEV1 within its defined allocation limits than
would normally have occurred.  A later patch fixed this problem, as I
remember.

User volumesets do not support transient space, so any allocation above 0%
for this domain, while set and reported by VOLUTIL, is ignored.

Lee Gunter
============================================================
Supervisor, TRG HP/MPE Systems
The Regence Group
Phone:              503.375.4498
Fax:                     503.375.4401
E-mail:             [log in to unmask]
============================================================
All opinions expressed are just that -- opinions.  They're
mine and mine alone.




From: Tom Hula <[log in to unmask]> on 07/26/99 08:45 AM

Please respond to Tom Hula <[log in to unmask]>


To:   [log in to unmask]
cc:    (bcc: Lee Gunter/BCBSO/TBG)
Subject:  [HP3000-L] Permanent & Transient Disc Space




I just added a new disc drive and added it to the system volume set and
all went well.  What I'm curious about is the percentages for max
transient and max permanent space using altervol in volutil.

The new drive ended up defaulting to 95% and 95% (the manual says the
dafault is 100% and 100%) ... the manual says that LDEV 1 defaults at
75% and 75%.  Why can this even be set?  What use is it?  Why do I need
to give up 25% of the usable space on LDEV 1?  Does is end up taking 25%
away from permanent space that can be used by transient space?  Why did
the new drive end up at 95% 95%?  What is the strategy involved here?
The documentation is pretty bare bones.