How to Back Up On An Emulated 3000
June 20, 2013
Stromasys product manager Paul Taffel is reading our reports closely (always a good idea, to keep up with the latest in your community.) Upon reviewing yesterday's story -- which included an account of the operations a prospective user said he still needs to investigate -- Taffel quickly offered answers to a key question about backups using the CHARON HPA/3000 product.
The 3000 manager, who's investigating emulation en route to a migration, asked
How do we do backups and restores with the emulator? Its architecture is that each HP 3000 LDEV is a separate Linux file, so identifying where MPE files are for backup and restore looks more difficult. If I need to restore a file to one of our production accounts, how do I identify which Linux backup it is on, and how do I then mount that virtual disk to do an MPE restore?
Taffel replies
Copying entire CHARON disk image files is only useful as a way to back up an entire disk (or collection of disks) for Disaster Recovery purposes. To create a backup that is useful for restoring individual files, use the MPE STORE command (or a third-party tool) to write the backup, either to a physical tape (internal SCSI, or external USB drive), or to a virtual tape image. Virtual tape images are stored as files on the Linux server; they can hold the contents of any Store (or SLT) tape, but take far less time to write.
The technique of copying an entire CHARON disk image file is useful when moving an entire virtual HP 3000 to another server, or returning the local server to a prior state. You can, for example, back up your system, conduct a test of your month-end processing, and then return your system to its original state, quickly and easily, by copying the Linux folder containing your disk images. One important note: the virtual CHARON HP 3000 must be shut down before copying the virtual disk image files.