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Utilities for the Next Generation
By: Walter Metcalf
Introduction
One of the problems facing any loyal OS/2 user is how to handle the new disk I/O system that's an integral
part of every version of OS/2 Warp higher than v4 Fixpak 15. This includes all Convenience Paks, OS/2 Warp
Server for e-business, and the eComStation family of systems. From an IBM
document entitled, Aurora File System Services White Paper
the reason for the new I/O system seems to be to update the antiquated software--specifically
the FDISK program and the file systems it supports--and bring it into line with modern disk technology.
(After all, FDISK was designed for the original small (e.g. 10 MB) hard drives, and it is still being used
with hard drives in excess of 70 GB in size!)
No one questions that FDISK was hopelessly out-of-date, and needed to be replaced. Unfortunately, however,
IBM only made the new disk system partially backward compatible: once a disk system has been converted,
it can never again be accessed using the old FDISK methodology. Worse, these new systems aren't content to convert
a specific partition, or even a physical drive. They actually convert every physical drive connected to your
computer. (This should give one pause before installing one of the new OS/2 systems on a computer having a
Windows system. I intend to test this, but was unable to do so in time for publication. In the meantime, the
safest thing to do is to keep your Windows system on a separate computer or removable hard drive.) This is because the new operating systems use the Logical Volume Manager (LVM) , which
amounts to a complete rewrite of the OS/2 disk input/output system, based, as we have seen, on the disk system used in the AIX system, IBM's UNIX clone. (For more
details, see my article on LVM, especially the
bibliography at the end of the article.
Regarding the LVM, all OS/2 software currently in existence falls into four categories:
- High-end applications
- This category refers to programs (such as PMView) that do not manipulate the hard drive
directly or use any so-called "low-level" commands. They use only the existing drive and
partitioning structure.
- Low-order programs (e.g. drivers) that specifically state (via error message or documentation)
that they're incompatible with the aforementioned versions of OS/2.
- For example, Daniella's DASD Manager release 1.0.0 contains the following warning in the
documentation:
DaniDASD.DMD is made for non-LVM systems only!
It does not work with OS2LVM.DMD!
It can not overcome limitations of FDISK or OS/2 Bootmanager!
Daniella is to be commended for stating this limitation up front in the documentation.
- Programs that don't state their compatibility or incompatibilty with the new operating systems.
Old software, especially utilities, that have not been updated recently fall into this category,
but all programs that manipulate partitions, access the partition tables, or attempt to format disks,
should be tested before used with the new systems.
- Finally, a few programs, unfortunately a small minority, contain features actually designed to
assist us with the new generation of OS/2 systems. In a few cases these are new programs, in others,
new features have been added to the existing program.
Purpose
The purpose of this article is to examine some of these programs that have been written or modified to
assist us as we enter this new realm of OS/2 software. These programs will be especially helpful as we
convert our systems to any of the new versions of OS/2 that contain the Logical Volume Manager.
Programs/Utilities
- IBM Utilities
These utilities are supplied with OS/2.1
- LVM
This utility is supplied with OS/2 and is the primary means of accessing and manipulating the
hard drives using the Logical Volume Manager software. This utility allows you to:
- Delete/Create Volumes and Partitions
- Expand Volumes
- Assign and change drive letters
- Create and populate the Boot Manager
- etc.
The first time LVM is used on a system, it runs a utility to make sure all partitions
on all drives connected to the system are compatible with LVM, i.e. that they have
been converted to LVM Compatibility Mode. Any that haven't been, it converts. The data
is preserved, but it can no longer be accessed with most of the older disk utilities,
such as FDISK and Partition Magic.
- LVMGUI
The Java GUI equivalent of LVM. In some ways it's a little easier to use than LVM,
but the window is smaller, and it is much slower.
- CHKDSK
Switches have added to provide special processing for JFS volumes.
- FORMAT
Switches have been added to allow specifying characteristics unique to the JFS file system.
- DEFRAGFS
New utility to defragment JFS volume.
- EXTENDFS
New utility to adjust JFS file system after LVM volume has been enlarged using the LVM utility.
- CACHEJFS
New utility to read the JFS cache settings.
- CHKLGJFS
New utility that shows a formatted log of the last CHKDSK process.
- FileStar 3.0
Although FileStar only has minimal interaction with the file system, that which it does have
appears to be solid and consistent. (Note: I am using a beta version of version 3.0 for testing.)
In my email conversations with the author he said he intends to make FileStar 3.0 fully functional
under both JFS and LVM.
- FORMAT
The FORMAT menu item is sensitive to the kind of drive selected, and only displays JFS as an
option if the drive is capable of being formatted this way. If the select drive is Compatible, for example,
then JFS does not appear as an option on the FORMAT DISK box.
- Create Directory
FileStar doesn't have a specific set of commands for creating or manipulating partitions. This is
apparently handled by clicking on the menu item to open an OS/2 command window, and entering the
desired command there. I tried it, and entered LVM. FileStar launched a VIO window containing
LVM. I entered the LVM instructions, and after I was finished, I closed LVM, and
was returned to FileStar. The whole operation was very smooth and fast.
- DFSee
Please see Surf Your Hard Disk with DFSee for a full
review of this product. Since this review, the author has added a number of features, many of
which pertain to the new OS/2 systems and another which pertains to running OS/2 on the
same computer as Windows 2000, a problem more of us are being faced with all the time.
- Windows 2000 feature
Let's look at the Win 2K feature first: The DFS command W2KBM (no parameters) modifies the
IBM Manager so that Windows 2000 will not corrupt it.
- DFSNT
(NT version of DFS) avoids the OS/2 LVM drive-letters.
- FDISK
An important point to note is that the name is the only thing in common between this DFS
utility/command and the old IBM utility. The author has written all the code himself, and
it is completely compatible with both JFS and LVM.
- PSAVE/PRESTORE
These important utilities/commands save and restore the partition and LVM information
of a volume to a file.
- VCU
Runs the external VCU utility to create the VCM information.
- SETLET
Assigns a drive letter to a partition.
For a complete list of commands, see the online documentation.
This concludes this series on updates to the Disk Input/Output. Next week we will have a change of pace by
doing a review of ZipStream 2.0. This unusual software package allows the user to compress and decompress his data
on the fly. Please join us then.
Walter Metcalf
Notes
1 For more information on each of the IBM utilities, see my article entitled, Notes on OS/2 Disk Usage IV - The Journaled File System (JFS), Concluded and Inside OS/2 Warp Server for e-business, Chapter 4.
Unless otherwise noted, all content on this site is Copyright © 2004, VOICE
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