Using Logical Volume Manager

By: Walter Metcalf
Date: 11/08/00

In eComStation, the OS/2 Warp Convenience Paks, which are scheduled to begin shipping on 30 November 2000, and Warp Server for e-Business, FDISK and FDISKPM have been completely replaced by two new programs, Logical Volume Manual (LVM) and the Java version, LVMGUI.1 If you attempt to run either of the FDISK programs, you will receive a message telling you to run LVM or LVMGUI instead.

Logical Volume Manager (LVM) and its GUI counterpart (LVMGUI) are very powerful programs with a host of features, including some utilities-documented and undocumented. Detailing each of these features and its use would require a short series by itself. Moreover the version of LVM invoked by the eCS installation program is only a subset of the full LVM.2 This article will therefore be restricted to that subset encountered during installation. I may write a more complete exposition of LVM at a later date.

Installation Express

  1. Boot Manager

    Assuming you have a completely empty hard drive, the first thing the eCS installation will do after loading the initial software is to automatically start the special version of LVM, and open it to the "Logical View" with the cursor set at "Install Boot Manager". (As noted in last week's article, this version of Boot Manager is a much overdue upgrade from the one shipped with Warp 4 and previous versions. As far as I have been able to determine this version is backward compatible with the Warp 4 version, and it is also compatible with FAT32 and modern very large drives. Therefore if eCS installs it on a drive with Warp 4, DO NOT remove it. Not only will you lose functionality, but you risk damaging the disk structure of your drive(s).)

    1. To install the Boot Manager, select "Install Boot Manager" and press <Enter>.

    2. Boot Manager Options.

      1. Default Boot Selection - (greyed out)
      2. Timer Active - Yes/No
      3. Timeout Value - 30 sec.
      4. Display Mode - Advanced/Normal
        Note that these are identical to the Warp 4 version. Default Boot is greyed out because no partitions have been defined yet.

  2. Creating Volumes

    1. To create a volume, select "Create a Volume" and then "Create a volume that needs to be made bootable". (For simplicity we'll assume this is your system drive.) Press <Enter>.

    2. Select the drive letter you wish assigned to this volume, and press <Enter>. (Note the increased control over drive letters compared with Warp 4.)

    3. Enter the name you wish to assign to this volume. Press <Enter> twice.

    4. Select the Hard Drive in which you want to create the volume. Press <Enter>.

    5. Select "Allocate from Free Space". Press <Enter>.

        Note: this option will always be the only one available when you started with a clean hard drive, as we did here.

    6. Since no partition was found, LVM will now create one.

    7. Select the appropriate free space area for the partition, and press <Enter>.

    8. Enter the name you wish to assign to this partition, and press <Enter>.

    9. Enter the size in megabytes to be allocated to the new partition, and press <Enter>. 3

  3. Setting the Default Boot Volume.

    1. Select the desired volume, and press <Enter>. The Boot Manager menu will appear.

    2. Select "Set Boot Manager startup values, and press <Enter>.

    3. Select "Default boot selection", and press .

  4. Saving your Work.

    1. Press <F3> to bring up the exit menu.

    2. Cursor down to "Save the changes and exit," and press <Enter>.

    3. A window is displayed explaining that you must reboot the computer.

        Note: The disk software for the eCS/Convenience Pak/WSeB has been redesigned so that much of the time it is not nessary to reboot after changing partition/volume information. However, in certain cases, as when making changes to or creating a boot partition, it is still necessary to do a reboot.

Creating Non-Boot Volumes

There are actually two ways to create a volume:

    Create the Partition first, then create the volume. Create the Volume from unallocated space, and create the partition "on the fly" as we did in the previous section. This is preferable in the that case because it is quicker and there is nothing to be gained by creating the partition first. However, that technique might be useful on a drive that was already partitioned.

    1. Creating LVM Volumes.

      1. Press <F5> to select the Physical View (if necessary).

      2. In the top window, place the cursor over the physical drive to be partitioned. Press <Tab>.

      3. Place the cursor over the free space where you want to place the partition. Press <Enter> twice.

      4. Choose either Primary or Logical Partition. Then press <Enter>.

        1. "Primary" and "Logical" here have the same meaning as in other OS/2 systems. A good rule of thumb is to make a partition "Primary" only if it is absolute necessary (e.g. it is going be used as a DOS partition). Otherwise make it "Logical".4

      5. Choose the location of the partition. (Generally, you should select the beginning of the free space, unless it is necessary to do otherwise.) Press <Enter>.

      6. Enter the name for the new partition, and press <Enter>.

      7. Enter the size in megabytes for the new partition, and press <Enter>.

      8. Place the cursor over the free space, and using the steps above, create a second logical partition, adjoining the first.

        1. Note that both of these partitions are indicated to be "Available" under the heading "Status". This means they are not assigned to a volume.

      9. Press <F5> to switch to the Logical View, and press <Enter>.

      10. Select "Create a new volume" and press <Enter>.

      11. Select "Create a volume that does not need to be bootable" and press <Enter>.

      12. Select "Create a LVM volume" and press <Enter>.

      13. Select a drive letter and press <Enter>.

      14. Enter the name for the new volume, and press <Enter>.

      15. Select a physical drive for the new volume, and press <Enter>.

        1. Note that both options are now available.

      16. Select "Use existing partition", and press <Enter>.

      17. Select a partition for the new volume, and press <Enter>.

      18. If you wish to change the name of the partition, enter it now.

      19. Press <Enter>. Note that the partition you selected is no longer marked "Available".

      20. Using steps 15 - 19, add a second partition to the new volume.

      21. Press <F6> to finish creating the new volume, and switch to logical view.

      22. Select the new volume in the upper window, and note that both partitions contained therein are displayed in the lower window.

        1. Note also that the new volume is marked as LVM, not Compatibility.

    Miscellaneous Functions

    1. Expanding a Volume

      1. Only LVM volumes can be expanded.

      2. Make sure the LVM is in the logical view mode.

      3. Press <F5> to switch to the physical view.

      4. Select a physical drive.

      5. Press <Tab> to go to the lower window.

      6. Place the cursor over a "free space" entry, and press <Enter>.

      7. Select "Create a new partition", and press <Enter>.

      8. Select "Logical partition" or "Primary partition" as appropriate, and press <Enter>.

      9. Choose location of new partition, and press <Enter>.

        1. This partition need not be contiguous (i.e. adjacent) to the others in the current volume.

      10. Enter the name of the new partition, and press <Enter>.

      11. Enter the size of the new partition in megabyes, and press <Enter>.

      12. Press <F5> to switch to logical view.

      13. Select the LVM logical created in the preceding section, or any other LVM volume, and press <Enter>.

      14. Select "Expand the volume", and press <Enter> twice.

      15. Select the physical disk drive you wish to use from the upper window, and press <Enter>.

      16. Select "Use existing partition", and press <Enter>.

        1. It's possible to expand a volume by adding free space directly, but in that case LVM first turns the free space into a partition "on the fly" in a manner analogous to the technique seen used in the section "Creating LVM Volumes".

      17. Select the partition you wish to add to the to volume.

      18. If you wish to change the name of the partition, enter it now.

      19. Press <Enter>.

      20. Press <F6> to finish the volume operation.

      21. Select the LVM volume just expanded from the upper window, and note that the volume now contains an additional partition. Note also that these partitions need not be contiguous.

    2. Deleting a Volume

        Using the Volume Delete function is completely obvious, so the steps will not be detailed here. However there are some important points that need to be pointed out.

      1. Deleting a volume also deletes ALL PARTITIONS it contains. This is contrary to what one might expect. Since a volume can contain multiple partitions, or even hard drives, this makes Volume Delete potentially a very DANGEROUS function. Be very sure you know what you are doing.

      2. Volume Delete can be used with both LVM and Compatible volumes.

      3. Partition Delete can only be used with "Available" partitions, that is, those not assigned to volumes.

    I hope this brief treatment of LVM will make your installation of eComStation and transfering of application files easier. If you have further questions, please check the articles under "For Further Reading", or contact me at "TalkBack"

    Walter Metcalf

    For Further Reading:

    Partition Tables (Revised)
    A thorough treatment of hard disk partition tables. From your Guide.

    A Short Introduction to LVM and JFS
    From VOICE Newsletter by Michal Necasek


1 While these functions may be new to OS/2, they are not really new. IBM developed them for their AIX systems--their high-end Unix clone. This means any of the really serious problems have already found and fixed.

2 For example the GUI version of LVM is unavailable during installation.

3 Note that all bootable volumes are set to compatibility type.

4 For a more technical explanation of these terms, see my article Partition Tables.

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