Data Protector and OpenVMS 7.3-2

[Karen Lee_3]

One of my remote sites want to start using DP ( I have no experience with it). Can I use native VMS commands to recover data if the system is down? any gottcha's I should be aware of?

[Jan van den Ende · Accepted solution]

Karen.


Can I use native VMS commands to recover data if the system is down?

Short answer: No.

You will have to boot (any) bootable environment. Then you have to get the DP software going.
From there on you can do the restore(s).

Of course, most of this can (and should) be prepared beforehand.

Have a system disk WITH DP INSTALLED ready to bot from in case of need, and the instructions how to boot from it.

All-in-all pretty straightforward.


any gottcha's I should be aware of?


You will have to be make sure that your "emergency system disk" is _KEPT_ synchronous with your "live" system disk.

Any upgrades & patches (both VMS _AND_ DP ) have to be installed on the emergence disk as well. And this requires secure planning, and strict adherence. Most sites I know lack the discipline to maintain this, and tended to become sloppy overtime.
It is the main reason why I am VEHEMENTLY against any method that is _NOT_ based on native BACKUP.


hth

Proost.

Have one on me.

jpe

[Edwin Gersbach_2]

Karen,

We are using DP for our whole production environment (consisting of hundreds of VMS, *IX and Windoze systems). We use it together with two large tape libraries (disaster tolerance) and several cell-managers.

I have done extensive tests when we implemented DP for VMS and found the following problems with incremental backups:

Renamed directories get created (upon a restore) with the new name but remain empty. If the restore is done with "omit deleted files" the files in the original directory get deleted along with the directory. For a correct restore, this requires knowledge of such operations performed on a disk.

We noticed a problem with oracle where some (database backup?) files get created with the file dates from the original database. This means the files have the same name, creation and modification date each time they get created, while FID and size are different. VMS-Backup does notice this but DP does not because it neither considers FID nor the backup date provided by VMS. It just compares standard file attributes to its internal database - as it has to do with other (non-VMS) file systems. As far as I know this has been solved by a fix from oracle.

Both problems do not occure with full backups, but our nightly window is just too short for this. We can do full backups only over the weekend.

Also, for the system disks we perform a VMS image backup to a saveset on a data disk. This has two advanages:
1) in case of a failure of the system disk, it can be restored using just the VMS kit CD.
2) we don't trust DP (and never tested it's ability) to handle the complex structure of a system disk with its multiple links to [VMS$COMMON] and the boot bits.

Edwin