Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!news.larc.nasa.gov!ipsun.larc.nasa.gov!jcburt
From: jcburt@ipsun.larc.nasa.gov (John Burton)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Should Low level Format of Hard Disk be re-done on its new cntrlr?
Message-ID: <1991Mar29.135316.26107@news.larc.nasa.gov>
Date: 29 Mar 91 13:53:16 GMT
References: <5913@trantor.harris-atd.com>
Sender: news@news.larc.nasa.gov (USENET Network News)
Distribution: na
Organization: NASA Langley Research Center, Hampton, VA  USA
Lines: 57

In article <5913@trantor.harris-atd.com> sonny@trantor.harris-atd.com (Bob Davis) writes:
>
>	Should a hard drive which was originally low-level
>formatted on another controller be re-low level formatted
>on its present controller?
>
>	Are there variations from controller to controller
>that would make you definitely want to do this?
>
>Thanks.
>
>_____________________________________________________________________________
>Bob Davis, UofALA alum \\ INTERNET: sonny@trantor.harris-atd.com  |  _   _  |
>Harris Corporation, ESS \\    UUCP: ...!uunet!x102a!trantor!sonny |_| |_| | |
>Advanced Technology Dept.\\ AETHER: K4VNO          |==============|_/\/\/\|_|
>PO Box 37, MS 3A/1912     \\ VOICE: (407) 727-5886 | I SPEAK ONLY | |_| |_| |
>Melbourne, FL 32902        \\  FAX: (407) 729-3363 | FOR MYSELF.  |_________|


Hi Bob,

  I can answer your question with a definite maybe...:-)

Doing a low-level format with the new controller is not required unless
the old and new controllers use a different interleave factor. If they
have the same interleave, then you *might* get away without doing a low-level
format (depends on the machine - XT vs AT, and on the controller - onboard BIOS
vs no onboard BIOS). Basically it would be a good idea to do a LLF with the
new controller becaue:
 1) For disks w/ a stepper motor r/w head actuator, periodic LLF is a 
    good preventive maintenance routine. (not needed for voice coil actuators)
 2) For controllers w/ onboard BIOS (XT controllers and some AT controllers - 
    AT's have hard disk controller BIOS built into the motherboard BIOS - the infamous 
    AT disk drive tables) it allows you to tell the controller exactly how to work
    with the drive (Interleave factor, write-precompensation track, reduced write track,
    head landing zone, etc...) which would help get the optimum performance out of
    your drive (available storage space, transfer speed, etc...).
 3) Its a chance to see if you've developed any new bad blocks on your disk...

On the otherhand, if you do a LLF then you'll have to BACKUP/RESTORE the data on the
disk, which can be a pain for a large disk...

good luck...

let me know if this helps...

John

+--------------------------------------------------------------------+
| John Burton                                                        |
| G & A Technical Software                                           |
| jcburt@gatsibm.larc.nasa.gov                                       |
| jcburt@cs.wm.edu                                                   |
|                                                                    |
| Disclaimer: Hey, what can I say...These are *my* views, not those  |
|             of anyone else, be they employer, school, or government|
+--------------------------------------------------------------------+