• Information
• LVM Features
• LVM with OS/2 Warp 4
• IBM LVM Update
• JFS Features
• IBM JFS Update
• Bootable JFS for eComStation
• eCo Software's JRescuer/JUne for JFS
• FreeJFS (OpenJFS)
• Links

Because LVM was designed to be used with partitioned direct access storage devices (i. e. hard disks primarily) - which are managed by the OS2DASD.DMD device management driver - there is a problem with removable media. Media which are formatted with the Super Floppy Disk format (Big Floppy, Large Floppy) cannot be handled correctly, because they do not have a partition table (otherwise equal to FAT16). If you allow LVM to commit changes when exiting the program, it will write to inserted removable media in SFD format causing data corruption! So please eject such media before allowing LVM to perform write operations!
After the application of the LVM update buildlevel 14.105, LVM handles "Big Floppy" media correctly.

Do not perform any operations with FDISK (e. g. of Warp 4) which write to storage media, after usage of LVM!

LVM makes the PARTFILT.FLT partition filter driver which was/is included with some third-party filesystems like FAT32 obsolete.

Features of the FDISK successor Logical Volume Manager (LVM):

• partitioning of storage media
• spanning over multiple partitions, which may be spread over different hard disks, to become so called logical volumes
• dynamic expansion of logical volumes
• permanent, freely selectable drive letters

Because of their structure, FAT and HPFS filesystems are less suitable for spanning. That is why the usage of JFS is recommended.

Perform the following steps to add support for LVM to your OS/2 Warp 4 partition (requires FixPak XR*M013 or higher as prerequisite):

1. copy the following files from the boot partition to the corresponding directories of the Warp 4 boot partition:
   • \OS2\BOOT\OS2DASD.DMD
   • \OS2\BOOT\OS2LVM.DMD
   • \OS2\DLL\LVM.DLL
   • \OS2\SYSTEM\LVM.MSG
   • \OS2\SYSTEM\LVMH.MSG
   • \OS2\LVM.EXE
2. add this statement to the CONFIG.SYS right after the line containing OS2DASD.DMD:
   • BASEDEV=OS2LVM.DMD

• active support contract or eComStation registration
• IBM Driver for ATA/(E)IDE Harddisk and Removable Drives Support (14.100) or higher for support > 539 GB (502 GiB) as prerequisite

Some features of the Journaled File System:

• recovery of the filesystem in seconds to minutes through logging of changes before execution (journaling)
• cache up to 1 gigabytes (1/8 of installed memory ist default)
• file and partition sizes up to 2 terabytes
• up to 4 billion entries of directories and files
• variable block sizes of 512, 1024, 2048, 4096 bytes

Because JFS can suffer from fragmentation, a command line utility to defragment a JFS volume is shipped with it.

A JFS-formatted partition is not bootable by default! eCo Software developed a bootable JFS which is available for users of eComStation.

• active support contract or eComStation registration

• eComStation registration

• Logical Volume Manager (LVM) as prerequisite

• IBM Redbook (1999-07-21): Inside OS/2 Warp Server for e-business
• IBM Redbook (1999-09-21): Migrating to OS/2 Warp Server for e-business
• eCo Software - eComStation.Ru: Release of JUne
• JRescuer - eComStation.Ru
• JFS recovering methodology - eComStation.Ru
• Installing eComStation on a JFS Volume
• Notes on using logical volumes and the Logical Volume Manager (LVM)
• Alex Taylor: OS/2 LVM
• VOICE: A Short Introduction to LVM and JFS
• VOICE: LVM, FDISK and Partition Magic
• VOICE: Troubleshooting LVM Problems
• The WarpDoctor Clinic: Using the Logical Volume Manager
• The WarpDoctor Clinic: Notes on OS/2 Disk Usage I
• The WarpDoctor Clinic: Notes on OS/2 Disk Usage II - The Logical Volume Manager
• The WarpDoctor Clinic: Notes on OS/2 Disk Usage III - The Journaled File System (JFS)
• The WarpDoctor Clinic: Notes on OS/2 Disk Usage III - The Journaled File System (JFS), Concluded
• The WarpDoctor Clinic: Utilities for the Next Generation
• OS/2 eZine: JFS Cookbook
• OS/2 Filesystem Shootout