Appendix 9 Removing the OpenVMS Operating System

This appendix explains how to remove the OpenVMS operating system from your disk.

You can remove the OpenVMS operating system from your disk in the following ways:

If the disk contains a small number of user files, copy those user files elsewhere and then reinitialize the disk.
If the disk contains many user files, use the PRODUCT REMOVE command to remove an obsolete or extra copy of the OpenVMS operating system without removing any of the user files. You must also delete or archive certain operating system files that the PRODUCT REMOVE command cannot delete.



	NOTE: For systems supporting the Instant Capacity feature, CPU status (how many cores are available and how much time they have remaining) is not affected by removal of the operating system from your disk. Such information is stored in NVRAM on the Integrity servers.

Follow these steps to remove OpenVMS operating system files:

If your system disk has multiple system-specific roots, boot the system and execute SYS$MANAGER:CLUSTER_CONFIG.COM (on OpenVMS Alpha systems) or SYS$MANAGER:CLUSTER_CONFIG_LAN.COM (on OpenVMS Integrity server systems) to remove all roots except the one from which you are booted.
Shut down and boot from the distribution media or from a system disk other than the one from which OpenVMS is being removed. Then do one of the following:
- If OpenVMS is not running from the distribution media, log in to a privileged account.
- If OpenVMS is running from the distribution media, choose the option to execute DCL commands.
Enter the following DCL commands:
```
$ DEFINE/NOLOG PCSI$SYSDEVICE target-disk
$ DEFINE/NOLOG PCSI$SPECIFIC target-disk:[SYSx.]
$ DEFINE/NOLOG PCSI$DESTINATION target-disk:[VMS$COMMON]
```
where:
- target-disk is the device name of the disk from which OpenVMS is being removed.
- SYSx is the root number that you did not remove in step 1.
If the disk also contains layered products that were installed using the PCSI utility, HP recommends that you remove them as well. Remove any layered products before using the PRODUCT REMOVE VMS command.
Use the following command to remove all the products at once. Select the layered products you want to remove from the menu.
```
$ PRODUCT REMOVE * /REMOTE
```
Use the following commands to remove individual products:
```
$ PRODUCT SHOW PRODUCT/REMOTE
$ PRODUCT REMOVE product-name /REMOTE
```
Enter the following DCL command:
```
$ PRODUCT REMOVE VMS /REMOTE
```
Because the PRODUCT REMOVE command does not delete certain files, review the target disk to determine whether you want to delete, move, or archive the operating system files that still remain on the disk.
Following are lists of the files that the PRODUCT REMOVE command does not delete:
- In target-disk:[SYS*.SYSEXE], where * is the hexadecimal number of any additional OpenVMS Cluster root on the target disk:
  - IA64VMSSYS.PAR (OpenVMS Integrity server systems)
  - ALPHAVMSSYS.PAR (OpenVMS Alpha systems)
  - MODPARAMS.DAT
  - PAGEFILE.SYS
  - SWAPFILE.SYS
- In target-disk:[VMS$COMMON.SYSEXE]:
  - LMF$LICENSE.LDB
  - PCSI$FILE_SYSTEM.PCSI$DATABASE
  - PCSI$PROCESSOR.PCSI$DATABASE
  - PCSI$ROOT.PCSI$DATABASE
  - RIGHTSLIST.DAT
  - SYSUAF.DAT
As you examine the preceding lists of files, you might want to archive, rather than delete, the following files:
- IA64VMSSYS.PAR (OpenVMS Integrity server systems)
- ALPHAVMSSYS.PAR (OpenVMS Alpha systems)
- MODPARAMS.DAT
- LMF$LICENSE.LDB
- RIGHTSLIST.DAT
- SYSUAF.DAT
Also, if you previously removed layered products, those products might have created additional files that you might want to delete, move, or archive.
Review the target disk for the directory structures [VMS$COMMON...] and [SYSx...] that remain after you remove the OpenVMS operating system. You might want to delete these directories.
The directories [SYSx]SYSCOMMON.DIR (in all [SYSx]) are aliases for the file [000000]VMS$COMMON.DIR. Do not delete these SYSCOMMON.DIR files. Instead, use the SET FILE /REMOVE command as follows:
```
$ SET FILE /REMOVE [SYS*]SYSCOMMON.DIR
```
After you execute this command and delete, move or archive all the files in [VMS$COMMON...], you can delete [000000]VMS$COMMON.DIR. Then you can delete, move, or archive the files in each [SYSx] directory.