topic Re: Copy Files To DDS-2 Tape From Hard Disk & Vise-Versa in Operating System - OpenVMS

Copy Files To DDS-2 Tape From Hard Disk & Vise-Versa

monish_1 — Fri, 31 Oct 2008 12:23:52 GMT

Hi

I am using VAX/VMS V6.2 & I want to copy one file on my DDS-2 DAT Tape Drive.

Could anybody send me details step-by-step procedure to copy one file to tape drive as well as all files from directory & vise-versa?

Also when we have to use & difference of mount/foreign & mount/over=id command.

Thanks in advance

Bye

Monish

Re: Copy Files To DDS-2 Tape From Hard Disk & Vise-Versa

Steven Schweda — Fri, 31 Oct 2008 13:27:34 GMT

As usual, many things are possible. Why do
you wish to do it? Backup? File transfer to
a non-VMS system? To another VMS system?

HELP BACKUP
HELP COPY
HELP MOUNT
Look for VMSTAR (freeware)

BACKUP normally uses (or does) MOUNT
/FOREIGN. For COPY, you normally want a
non-/FOREIGN mount.

Re: Copy Files To DDS-2 Tape From Hard Disk & Vise-Versa

Hoff — Fri, 31 Oct 2008 14:09:39 GMT

Here's the basic sequence:

$ INITIALIZE ddcu: foo
$ MOUNT ddcu: foo
$ COPY file ddcu:[000000]
$ DISMOUNT ddcu:

This probably won't suffice for your requirements, as there is a whole lot more to copying a file than, well, the copy operation itself. (This is why us ITRC folks then ask for background on the question; why you're asking the question or what your particular goal here is can be and often is as important as the specific question itself.)

Read the manuals. Get some training. However you best learn, spend some time learning about OpenVMS.

Here, that reading tends to be the OpenVMS User's Guide manual and particularly the System Manager's manuals.

If you don't have the time or the budget to read the manuals and to experiment, or to obtain more formal training, then do consider a formal support and escalation contract. ITRC isn't a support channel.

nb: DAT/DDS tape drives should best be considered single-use media. I've experienced maybe a dozen disk backup passes of the average cartridge, and DAT/DDS drive and media failure rates are far higher than DLT. This can mean a new backup DAT/DDS cartridge weekly for an automated daily backup. DLT cartridge and drive failure rates are much lower. (You do get what you pay for, after all.)

Re: Copy Files To DDS-2 Tape From Hard Disk & Vise-Versa

AEFAEF — Tue, 04 Nov 2008 14:28:49 GMT

Don't use DDS-2 tapes; use DDS-1 instead. I have DDS-2 drives and I have had a lot of trouble with DDS-2 tapes. They would often not read on other drives or crap out part way through with parity errors. I have had much better luck with DDS-1 tapes. So far they read on any of my drives except one, which can't read other drives' tapes and can't write tapes that other drives can read!

Bottom line: USE DDS-1 TAPES in your DDS-2 drives.

Better yet, follow Hoff's suggestion and get a DLT drive.

AEF

Re: Copy Files To DDS-2 Tape From Hard Disk & Vise-Versa

Robert Gezelter — Tue, 04 Nov 2008 15:22:52 GMT

Monish,

I must concur with Steve and Hoff. There are several different ways to "copy a file to tape" and each has different uses and implications.

What the copy is being used for is critical.

MOUNT/FOREIGN effectively ignores the contents of the tape and does not imply that the tape will be used according to the ANSI standards for magnetic tape formatting. MOUNT/OVERRRIDE=ID merely ignores the volume label on the tape.

If using BACKUP, it is normal to use MOUNT/FOREIGN since BACKUP generally uses physical blocks that are longer than those permitted by the ANSI standard.

- Bob Gezelter, http://www.rlgsc.com