RE: (Fwd) Re: (Fwd/Oracle) Does NT write to random locations on d

From: Mohan, Ross <MohanR_at_STARS-SMI.com>
Date: Tue, 13 Mar 2001 08:23:11 -0800
Message-ID: <F001.002CAE7E.20010313074533@fatcity.com>

EP,

*excellent* post. Most useful! Thanks.

All I can add is that O&O Defrag does an MFT defragmentation, too! (Isn't that cool?)

Ross

-----Original Message-----
From: Eric D. Pierce [mailto:PierceED_at_csus.edu] Sent: Monday, March 12, 2001 7:05 PM
To: Multiple recipients of list ORACLE-L Subject: Re: (Fwd) Re: (Fwd/Oracle) Does NT write to random locations on di

Folks,

here is the maze of amazing info from Andrew Baker's NT support web site:

> URLs:
>
> http://www.ultratech-llc.com/Personal/Files/?File=Defragger.TXT
>
> "If you're looking for some proof of how fragmentation can
> negatively affect your system, see the following:"
>
> http://support.microsoft.com/support/kb/articles/Q228/7/34.ASP

---excerpts---

Windows NT Does Not Boot with Highly Fragmented MFT

...

SYMPTOMS The Windows NT Start menu does not respond when you start your x86-based computer. A blinking cursor may appear in the upper-left corner of the screen, or an error message may be displayed. This issue only affects computers whose system partition (the partition containing NTLDR and Boot.ini) is formatted with the Windows NT File System (NTFS) file system.

CAUSE This issue occurs because the low-level bootstrap code contained in the first few sectors of an NTFS volume can not cope with a situation where the volume's master file table (MFT) is highly fragmented.

The role of the bootstrap code is to locate and load the NTLDR file into memory. To perform this function, the bootstrap code must understand NTFS data structures well enough to locate NTLDR on the disk. This task involves reading the volume's MFT in order to obtain the root directory, which in turn contains information necessary to locate the entry in MFT for the NTLDR file itself.

The initial bootstrap code is very small and simple and runs in the processor's "real mode". Therefore, it cannot address large amounts of memory. When MFT is highly fragmented, the Windows NT 4.0 bootstrap code may run out of memory to store all the necessary records that describe MFT. This causes the system to stop responding (hang) and thus, the boot process does not proceed.

RESOLUTION Windows NT Server or Workstation 4.0

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update.

...

WORKAROUND To work around this issue, a discussion of MFT fragmentation, together with one method of preventing excessive MFT fragmentation, is presented in the following Microsoft Knowledge Base article:

Q174619 How NTFS Reserves Space for its Master File Table (MFT) ( http://support.microsoft.com/support/kb/articles/Q174/6/19.ASP )

After the system drive is sufficiently fragmented such that the system cannot start directly from the hard disk drive, it is still possible to start through a Windows NT startup floppy disk. This is possible because the floppy disk contains its own copy of NTLDR. For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

Q119467 Creating a Boot Disk for an NTFS or FAT Partition ( http://support.microsoft.com/support/kb/articles/Q119/4/67.ASP )

...

MORE INFORMATION The Bcupdate.exe program updates the low-level bootstrap code stored on NTFS volumes. All NTFS volumes contain bootstrap code, but the code is used only on system volumes.

Because the bootstrap code is a part of the file system and not a part of any "user" file that can be replaced, it is not affected by the application or removal of hotfixes or service packs. Once updated, the boot code remains fixed until the volume is reformatted or the boot code is replaced by some other process (such as that performed by Emergency Repair when it repairs the boot environment).

Microsoft has no plans to incorporate automatic bootstrap code updates as part of a future Windows NT 4.0 service pack installation. To update the bootstrap code and resolve a boot issue of this kind, it is necessary to run Bcupdate.exe.

...

---end---

EXCELLENT explanation of other components of NTFS, and how fragmentation in those areas can effect performance:

http://www.microsoft.com/TechNet/winnt/optntfs.asp

---excerpt---
..

NTFS Performance Factors

You determine many of the factors that affect an NTFS volumes' performance. You choose important elements such as an NTFS volume's type (e.g., SCSI, or IDE), speed (e.g., the disks' rpm speed), and the number of disks the volume contains. In addition to these important components, the following factors significantly influence an NTFS volume's performance:

- The cluster and allocation unit size

 -  The location and fragmentation level of frequently accessed files,
    such as the Master File Table (MFT), directories, special files
    containing NTFS metadata, the paging file, and commonly used user
    data files

- Whether you create the NTFS volume from scratch or convert it from an existing FAT volume

- Whether the volume uses NTFS compression

- Whether you disable unnecessary NTFS behaviors

Using faster disks and more drives in multidisk volumes is an obvious way to improve performance. The other performance improvement methods are [***]more obscure[***] and relate to the details of an NTFS volume's configuration.

---end---

>
>
> -----------------------------
>
> Q. Is there an NTFS defragmentation tool available?
>
> http://www.windows2000faq.com/Articles/Index.cfm?ArticleID=13714
>
> -----------------------------
>
> August 1998 ... John Savill
> Troubleshooting Windows NT File Systems
>
>      Tweak your file systems
> This month I discuss how to improve
> your file system performance and how to manipulate the way Windows
> NT handles file systems. Tweaking file system performance involves
> modifying the Registry, so you need to create an Emergency Repair
> Disk (ERD).
>
>     The easiest way to boost your file system performance is to
> defragment your hard disk regularly. The blocks that make up a file
> become separated over the disk, so the physical disk heads must
> move over more of the disk to find them. Disk defragmentation moves
> these blocks to contiguous disk areas and thus results in faster
> access.
>
>      Microsoft originally thought NTFS did not fragment, so NT
> does not come with a defragmentation tool. ...
>
> http://www.win2000mag.com/Articles/Index.cfm?ArticleID=3675
>
> -----------------------------
>
>    Enterprise Defragmentation Utilities
>    To centrally manage and automate defragmentation on your servers
>    and workstations, you need a full-featured defragmentation
>    utility. This comparative review examines the fetures and
>    performance of three prominent defragmentation products.
>    Windows 2000 Magazine
>    Tom Iwanski/Lab Comparative
>    January 17, 2001
> http://www.win2000mag.com/Articles/Index.cfm?ArticleID=16442&pg=1
>
> -----------------------------
>
> related articles:
>
>
>    The Challenge of Defragmenting an NTFS Partition
>    Find out how you can overcome NTFS's unique hurdles.
>    Windows 2000 Magazine
>    Tom Iwanski/Lab Comparative
>    January 17, 2001
> http://www.win2000mag.com/Articles/Index.cfm?ArticleID=16444
>
> -----------------------
>    Windows NT System Management: A Collection of Topics
>    No operating system can be installed once and ignored. As
>    applications, users, and hardware components are added, the need
>    to configure, monitor,
>    tune, and protect the integrity of the operating-system
>    environment increases. With this in mind, the ...
>    Windows IT Library
>    March 12, 2001
> http://www.windowsitlibrary.com/Content/169/01/17.html
>
>
> -----------------------
> [RAID and defragging:]
>    Tech Stories from the Trenches
>    Find out why defragmenting disks make sense and how one
>    defragmentation tool improves performance.
>    Windows 2000 Magazine
>    Paula Sharick/Lab Feature
>    July 01, 1998
> http://www.win2000mag.com/Articles/Index.cfm?ArticleID=3583
>
> -----------------------
>    Optimizing Disks
>    This chapter explores a number of ways to optimize the performance
>    of Windows NT's disk subsystem. Using these methods in conjunction
>    with the proper hardware selections will ensure that your NT disk
>    subsystem provides excellent performance and will ...
>    Windows IT Library
>    March 12, 2001
> http://www.windowsitlibrary.com/Content/435/07/8.html
>
>
> -----------------------
>    NT Optimization 101
>    This chapter discusses some of the basic concepts of Windows NT
>    optimization, including an introduction to the various tools
>    employed to optimize NT, and several fundamental procedures you
>    should start with to increase system performance.
>    Windows IT Library
>    March 12, 2001
> http://www.windowsitlibrary.com/Content/435/04/7.html
>
>
> -----------------------
>    PerfectDisk 2000
>    Defragment your disk - even the Master File Table.
>    Windows 2000 Magazine
>    Michael Norian/Lab Reviews
>    June 13, 2000
> http://www.win2000mag.com/Articles/Index.cfm?ArticleID=8948
>
>
> -----------------------
>    Diskeeper 5.0
>    Set it and forget it.
>    Windows 2000 Magazine, Windows 2000 Magazine
>    Michael Norian/Lab Reviews
>
>
>                     June 05, 2000
>
>
> -----------------------
>    Diskeeper 3.0
>    Defragment your NTFS partitions Most Windows NT 4.0 users have
> silently cursed NTFS and NT's lack of a defragmentation utility. Even
> within NTFS,
>    individual files and free space on a disk partition are not
> contiguous; rather, they are broken up and ...
>    Windows 2000 Magazine
>    Carlos Bernal/Lab Reviews
>
>
>                     May 01, 1998
>
>
> -----------------------
>
>

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Eric D. Pierce
  INET: PierceED_at_csus.edu


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: ListGuru_at_fatcity.com (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).

Received on Tue Mar 13 2001 - 10:23:11 CST