----- Original Message -----
Sent: Tuesday, August 14, 2001 12:28
PM
Subject: RE: USEOPTBLK effect on which
drives?
Hi Sue! Is
H.A. your middle name? <g> Is the fishin' good in
Silverlake?
Speed is not as much
a factor as is the desire/goal/requirement to get the backup done on two tapes
and not three. I risk alienating the users who now have to put in a
second tape first thing in the morning if I tell them that there's now a third
tape to deal with every day.
Unless we reach a
crisis point with our ability to do a complete backup, there will be no
further hardware expenditures. The best I may be able to do is to switch
a 7208-222 from one of our other boxes with the 7208-012 on the
capacity-challenged machine so that I can use 7GB cartridges as opposed to the
5GB's.
COMPACT(*YES) brings
a syntax error at V3R7. The only valid values are *DEV and *NO. I
use the default value of *DEV. According to the V4R5 system handbook, it
appears that the 7208-012 supports both the HDC (Hardware Data Compression)
and the IDRC (Improved Data Recording Capability) compaction algorithm.
But HDC seems reliant on the IOP; do all of the IOP attachments for the
7208-012 support HDC? (FWIW, it appears that we are using IOP
#2621.) Also the compaction algorithm appears to be dependent on the
tape subsystem controller; is this "built-in" to the tape drive
hardware?
*IF* our 7208-012
supports both HDC & IDRC, am I getting the maximum capacity by specifying
DTACPR(*YES) & COMPACT(*DEV) ?
Dan Bale
IT - AS/400
Handleman Company
248-362-4400 Ext. 4952
D.Bale@Handleman.com
Quiquid latine dictum sit altum
viditur.
(Whatever is said in Latin seems
profound.)
--------------------------
Original Message --------------------------
-----Original
Message-----
From: S Baker
[SMTP:gonfishinmn426@yahoo.com]
Sent: Tuesday, August 14, 2001 7:50 AM
To:
midrange-l@midrange.com
Subject: Re: USEOPTBLK effect on which drives?
Dan, USEOPTBLK works on the
7208-342 but not the other 7208 models.
DTACPR is really slow ... that's software compression of
the data before sending to tape.
Better to use COMPACT(*YES) and have the tape hardware do
the compression of the data.
Sue Baker
----- Original Message -----
From: Bale, Dan <mailto:D.Bale@handleman.com>
To: midrange-l@midrange.com <mailto:midrange-l@midrange.com>
Sent: Tuesday, August 14, 2001
12:57 AM
Subject: USEOPTBLK effect on which
drives?
Can someone point me in the direction
of the appropriate documentation that tells me whether USEOPTBLK(*yes) is
effective on a 7208 model 012 tape drive on a V3R7
system?
Does USEOPTBLK(*YES) do any compression?
The help text doesn't really say anything except that it may offer a
performance benefit. I wondered about compression since
USEOPTBLK(*YES) and DTACPR(*YES) cannot be used
together.
If I'm tight on tape space and I've got plenty
of time, would my better option be to use USEOPTBLK(*NO) and
DTACPR(*YES)???
Thanks!
Dan Bale
Handleman Company
midrange.com
