At 09:38 AM 9/25/98 -0500, Jerry Fochtman wrote:
>At 05:20 PM 9/24/98 -0700, Brian wrote:
>>Any thoughts on defragmentation using configvol on a 9 gig drive? I don't
>>get the same results as I do with my two 2 gig drives.
>
>/plug-alert
>
>Bradmark's tool "Disk Space Manager" (DSM) will quickly, and without any
>risk, improve the performance of your disc storage by not only
>defragmenting the drives, but also consolidating/balancing file extents.
>It also offers a host of other features to help effectively manage your
>disc storage environment.  DSM is fully integrated with HP's Transaction
>Manager to ensure the integrety of your data without the need for
>additional steps to verify the results.
>

As does De-Frag/X from Lund.  However, it has alway been my contention that
putting your data into the hands of a third-party vendor without having
some protection mechanism is unwise.  (By way of example, regardless of the
fact the I *implictly* trust Alfredo Rego and the gang at Adager, I'm sure
I have backups before I do significant Adager functions.) This is why I
will continue to recommend that no matter what disk maintenance product you
use (De-Frag/X, DSM, or VOLUTIL), you should periodically run FSCHECK to
verify the current status of your file system.  The CA ALL command within
the program will do the trick.  I've had to say this probably a million
times (so far) but using FSCHECK before and after using a disk maintenance
product will pinpoint for you (and HP) what exactly caused any particular
problem, should a problem arise.  For example, it is possible for extents
to be cross-linked.  That is, an extent could inadvertantly have a forward
or backward pointer (either to free space or to another file's extent) that
doesn't belong to the file in question.  (This is a pretty rare problem but
it *has* happened; enough so that precautions should be taken).  When a
file is cross-linked it can ruin your whole day.  FSCHECK (and De-Frag/X)
can detect this problem.  It would be wise at this point to have the
Response Center assist you in fixing this kind of problem.

My last point goes hand-in-hand with the FSCHECK issue.  That is, backups.
I will also continue to recommend backups before running disk maintenance
products in "update" mode.  This isn't because of and concerns about
particular products but rather I believe it to be good operational
procedure.

I now have *three* favorite phrases:  "It depends", "Business casual" and
"Never entrust your job to a disk maintenance product".

In regard to the general discussion of defragmentation products let me
strain a  bit of a gnat.  Defragmenting a complete disk drive is more aptly
named condensing.  Defragmentation, to my mind anyway, is really about
making fewer (or one) extent out of a file that has many extents, probably
across multiple disk drives.

Bill (No longer in that business but still emotionally invested in it)
Lancaster