Mounting tape container file in charon VAX

[Joewee]

We have a charon VAX in our environment.

I believe it takes backup of Vdisks in to virtual tape drives. Now one needs a file to be restored. From the backup logs I found the Volume label and the saveset name.

The files copied to this virtual files are saved as a container file in windows server.

I need to know how to mount that particular file to a virtual drive and perform restore.


$ sho sys
VAX/VMS V5.5-2 on node XXXXX 25-AUG-2010 17:28:04.32 Uptime 79 04:52:29


$ sho cpu

XXXXX, a VAX 6000-630
Multiprocessing is ENABLED. Streamlined synchronization image loaded.

PRIMARY CPU = 01
Active CPUs: 01 02 03
Configured CPUs: 01 02 03

$ sho dev mub05/full

Magtape $1$MUB5: (XXXXX), device type TA85, is online, file-oriented device,
available to cluster, error logging is enabled.

Error count 0 Operations completed 2997056
Owner process "" Owner UIC [0,0]
Owner process ID 00000000 Dev Prot S:RWED,O:RWED,G:RWED,W:RWED
Reference count 0 Default buffer size 2048
Density 6666 Format Normal-11
Allocation class 1

Volume status: no-unload on dismount, beginning-of-tape, odd parity.


Thanks

[Volker Halle · Accepted solution]

Joewee,

you need to look at your CHARON-VAX configuration file to find out, where the container file for this tape is located. You should find something like:

set MUB container[5]="C:\CHARON_TAPES\MUB5.vtape"

You need to first make sure, that the CHARON-VAX emulator has released the current .VTAPE file. You can force this with:

$ MOUNT/FOR/NOWRITE MUB5:
$ DISM/UNL MUB5:

Then rename the current MUB5.vtape file and rename (or copy) the XYZ.vtape, on which your backup savesets are stored, as MUB5.vtape (this is like 'physically inserting the tape').

Then MOUNT/FOR/NOWRITE MUB5: and use backup to extract the desired files from the correct backup saveset:

$ BACKUP/LOG MUB5:saveset.bck/SAVE/SEL=([dir]file) disk:[dir]/BY_OWN=ORIG

Volker.

[Joewee]

Hi Volker,

Many thanks for your reply.

So, for this I need access to the windows server which hosts this Charon-VAX. I will get that first.

Thanks! again




I want to know how this works? Is there any document which explains more of this tape container handling in detail? Please share.

[Volker Halle]

Joewee,

I'm not aware of any special documents regarding virtual tapes (.vtape) in CHARON.

It's a VERY simple concept:

You configure a tape device in your emulated CHARON-VAX and point it to a .VTAPE container file on your Windows disk.

Once OpenVMS writes to the 'tape', the data goes to the .VTAPE file and it grows. Once OpenVMS is finished writing to the tape, a DISM/UNLOAD will cause the emulator to deaccess the .VTAPE file, so you can rename or copy it. If you continue to use your old OpenVMS backup scheme, note that instead of removing the tape from the physical drives, you now have to rename (or copy) the .VTAPE file, BEFORE you start the next backup writing to that virtual tape.

To read from a .VTAPE file, you need to move that .VTAPE file to the 'correct place', i.e. give it the name configured for the virtual tape. Then mount it from OpenVMS.

Volker.

[Joewee]

Many thanks Volker. I'm clear now.

[Stanley F Quayle]

Should you get a CHARON-AXP (AlphaServer emulator) in your environment, the handling of virtual tapes is similar.

There is a utility provided with CHARON-AXP that lets you specify the name of the VTAPE file within VMS, so access to Windows is not required. It's not available for CHARON-VAX, unfortunately.

[Shameless Plug Alert (tm) - I am a CHARON reseller.]

[Joewee]

Please, I need One more information.

I found that no containers files are available in the destination folder from morning.But as soon as I submit the backup in the evening, It automatically mounts the tape for the command

$ mount/for mua5:

and the label is found to be blank and after that I can see the container file mua5_xxxxx.Vtape created on the destination.


So is this how it works?? Though there is no file in the destination folder, if we mount the tape it will create automatically?


the destination I mean is

set PUB container[5]="t:\tapefiles\mub5_xxxxx.vtape"


Thanks

[Volker Halle]

Joewee,

yes, if there is no MUB5_xxx.vtape file and you MOUNT the tape, the CHARON emulator creates an empty file for you. So the tape label comes back as an empty string - as you've seen.

If there is an existing MUB5_xxx.vtape file, that file will represent the tape contents.

Volkerl

[Joewee]

Oh thats great!! Many thanks Volker.

And I have restored the file successfully!!

[Joewee]

This thread helped in knowing the concept how virtual tapes works in charon VAX.

Thanks to Volker.