Title: RE: (Fwd) TAR# 1280667.996:Can NT/Win2k server OS defrag utilities

EP,

You are making a rather large assumption.

You are assuming they put the people who KNOW the
answer on tech support. Anymore, that is a fading
proposition.

Now "for the most part" I think the "iTar" gives you
recent-hire college grads, using MetaLink and internal
forums scanning for opportunities to "cut and paste" an
answer.  I ask you this: what do YOU think is the average
"keep time" of an employee in Oracle support? 2 years...
1 year....6 months?  I'd guess after a faceful of
training, they work in support for an average of
18 months (*maybe*) and quit or move on.

The (very very) few people who know the answers to
internals questions are likely (a) not working on
tech support, (b) not working for oracle anymore.

just my jaded $0.02

- Ross

-----Original Message-----
From: Eric D. Pierce [mailto:[EMAIL PROTECTED]]
Sent: Monday, March 12, 2001 2:27 PM
To: Multiple recipients of list ORACLE-L
Subject: (Fwd) TAR# 1280667.996:Can NT/Win2k server OS defrag utilities


Does anyone else get the impression that Oracle tech support
isn't really answering the question about OS fragmentation
below??????

I thought it was obvious that moving db files when the db is
open is likely to be a bad idea, but can't imagine why defragging
at the OS level when the db is closed would be a problem.

eg, I read an Oracle tech support note that describes how to
move db files from one NT machine to another. If one can move
the files from one machine to another, why can't the db files
be reorganized (at the OS level) on the *same* machine?

This seems like an obvious question (and probably a straightforward
issue), I don't understand why Oracle tech support is so ambiguous
and lacking in explanation/justification for their statements.

If they are so enthusiastic about exp/imp, why wouldn't they be
as interested in gaining performance by additionally optimizing
disk access at the OS level?

Or maybe I'm wrong and NT/Win2k actually does a really efficient job
of laying out large files (Oracle's pre-allocated db file storage)
just like Oracle tech support is hinting?

regards,
ep

bcc: campus SysAdmn gurus

------- Forwarded message follows -------
Date sent:              Mon, 12 Mar 2001 10:55:11 -0500 (EST)
To:                     [EMAIL PROTECTED]

                            Oracle Worldwide Support
                            Incident Tracking System

------------------------------------------------------------------------------
      TAR#: 1280667.996                  Reported: 10-MAR-2001 (CUS-3027991)
  Assigned: DATASRVW (CHFREEMA.US)        Updated: 12-MAR-2001 (CHFREEMA.US)
  Severity: Severe Loss of Service (2)
    Status: Soft Close (SCL)
  Platform: MS Windows 2000
   Product: Oracle Server - Enterprise Edition (8.1.7)
     RDBMS: 8.1.7
  Customer: TRUSTEES CALIFORNIA STATE UNIV
   Contact: Eric Pierce Phone: 916 278-7586
------------------------------------------------------------------------------
Can NT/Win2k server OS defrag utilities be *safely* used on the db files?
------------------------------------------------------------------------------
*** METALINK.US 10-MAR-2001 00:00:18 GMT ***

...

### Platform and O/S version, including patchset orservice pack level? ###
Oracle 8.1.x Micsosoft NT4 server or Windows 2000server.

### What version and patchset level of the database are you running?###
8.1.7.?.?

### Please describe your problem: ###

This is a generic question about behavior of Oracle8i on NT4 server
(or Windows2000 server): It is ok to use disk defragmentation
utilities (eg, Norton speedisk for NT) on the Oracle 8i db files? An
individual on the Oracle-L listserv says that NT defrag utilities
will corrupt the db files (he is claiming that the physical placement
of the db files at the OS block level is "fragile" from Oracle's
perspective). This seems to contradict my experience working with
Oracle7.3 on Netware, where it is quite possible to move db files
around, and then have Oracle see them in a new location and go on
operating normally. We are trying to set up a plan for dbserver
tuning/maintenance, and need to know if disk defragging is required
and/or advisable for performance and recovery reasons on
NT/Windows2000 servers. 

Thanks,
Eric D. Pierce
Student Services
CSU, Sacramento
reply by email:[EMAIL PROTECTED]
or phone (916) 278-7586

...

### What is the impact to your business because of thisproblem?  ###
could potentially be high, but it is not a current operationalissue

Contact me via : E-mail -> [EMAIL PROTECTED]




*** METALINK.US 10-MAR-2001 00:00:18 GMT ***
Automatically assigned via METALINK.


*** CHFREEMA.US 10-MAR-2001 00:12:49 GMT, 09-MAR-01 Local ***
You should never really defrag your database files. Your datafiles should
never need to be defragged assuming that you sized them appropriately.

If your database is open when you are doing the defrag it will corrupt your
data every time. With a 3rd party utility when the database is closed would
have to be tested to see if it would even work. Make sure that you take a
backup before you try this though.


*** METALINK.US 10-MAR-2001 00:58:03 GMT ***
New info : Friday March 9, 2001 4:56pm california time

That really doesn't help much, and seems to possibly
contradict the conventional wisdom of NT SysAdmns, which is
to defrag a file system constantly.
Please comment on the Oracle-l listserv post that started
the discussion:
(thanks!!! ep)
-----excerpt----
|Using a little utility called contig I noticed that the Oracle
| 8.1.6 datafileson my test NT server are quite fragmented, an
| average of 177 fragments perfile, 118 fragments for the OEM
| repository datafile.  The poor utilitycouldn't do anything with
| the database files, they are too large perhaps.
|
|These were created on an empty server, 8i release 2 went on it
| after a defrag,then the OEM.  This is on a hard disk with 1.2G of
| free space, none of thedatafiles come close to that.
|
| Why so many fragments?  Oracle created thosefiles in one pass,
| does NT write randomly to disk or what?
|
| Won't thishave an impact on my NT database's performance?
|
| Oracle says tablespacefragmentation is not a big deal, but
| fragmentation at the OS level matters.Supposedly that's why NT
| and WndowsXX came with defragmentation tools.
|
|???
|
| Is there a registry setting somewhere to tell NT to write
| contiguouslyto disk?
---end---



*** CHFREEMA.US 12-MAR-2001 15:40:53 GMT, 12-MAR-01 Local ***
The only way to defrag oracle files is to do an export/import. Any 3rd party
tool or OEM's defrag option will amount to the same thing. They will take an
export and then import the object back in and that will defrag the file.

Datafiles, if sized correctly, should never need to be defragged. If you are
concerned that there is fragmentation on your oracle file take an export.


------- End of forwarded message -------
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Eric D. Pierce
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

Reply via email to