topic Query on COPY command in Operating System - OpenVMS

Query on COPY command

Ronny_7 — Sun, 18 Apr 2004 20:58:41 GMT

Hi,

My customer is running on OpenVMS V7.2-2 on ES40.
He is running an application called Adabas

Every day, he will export the application's image into a dump file for backup.
Usually, he will use COPY command to copy this image dump file into a tape.

Recently he tried to copy the image dump from the tape into the disk and when he tried to access that image from the application, it was not successful.

He tried using BACKUP command and it works fine.

Customer has another site with same setup and they have no problem using the COPY command.

I need some advise on what could be the problem here.
Thank you.

Thanks and Regards,
Ronny

Re: Query on COPY command

John Gillings — Sun, 18 Apr 2004 23:42:03 GMT

Ronny,

Without a clear description of "it was not successful" it's impossible to say what the problem might be.
If the file is open or updated at the time a copy or BACKUP is taken, then there may be inconsistencies in the copy.
Please contact your application vendor to find the recommended mechanism for taking backups of application data.

Re: Query on COPY command

labadie_1 — Mon, 19 Apr 2004 01:56:42 GMT

Ronny

I read the following in the releases notes of
VMS722_FIBRE_SCSI-V0400

DIR-E-TAPEPOSLOST errors when can occur when a DIRECTORY
command is used on skip-filemark-capable tape drives.

Images Affected:[SYS$LDR]SYS$MKDRIVER.EXE

Have you applied this patch ?

Regards

Gerard

Re: Query on COPY command

Ian Miller. — Mon, 19 Apr 2004 03:03:31 GMT

Are the file attributes the same at both sites? Are the tape drives and VMS versions the same? The problem with copying files to tape is that is there is no verification that the file was copied.

Additionally BACKUP will preserve the file dates but copy will not - sometimes this can cause problems.

Re: Query on COPY command

labadie_1 — Mon, 19 Apr 2004 08:51:54 GMT

if it is the problem I thought of, there is a simple workaround, before mounting the tape, issue a

$ set magtape/fast_skip=never mua0:

if mua0: is the name of your tape.

Re: Query on COPY command

Martin P.J. Zinser — Mon, 19 Apr 2004 11:04:24 GMT

Hello Ronny,

can you do a dir/full on the database dump before the copy and after getting it back from tape? This might give one a clue on what file attribute changed. Also the exact error message you get from Adabas would be helpful.

Greetings, Martin

Re: Query on COPY command

John Abbott_2 — Wed, 21 Apr 2004 02:58:54 GMT

Hi Ronny,

You talk about export, dump and copy. ADABAS has two utilities on VMS, ADAORD (to export) and ADABCK (to dump). Both utilities write a single file to disk or tape. If you're writing these to disk and want to copy these off to tape, then you can use the ADAORD or ADABCK COPY command (which are very fast).

So, I think there might be some confusion from your statement, ie. which parts of it refer to vms commands and which refer to adabas commands.

If I remember right, an adabas block size is about 64K so if you use vms copy or backup and don't get your maths right you could end up slowing things down or not being able to restore the file (i.e. direct from tape using the adabas utility).

Oh, and of couse using vms backup will mean you'll have to restore the file to disk if you ever need to import (adaord) or restore (adabck) the file back into the database.

I wouldn't mix VMS backup save sets on tape with ADAORD or ADABCK Adabas backups.

Another hint, check the DBA account UAF values (in the ADABAS utiltiies manual) as you can squeeze some more milage out of ADAORD (asyc writes) with higher values, especially ASTLM + DIOLM. ADABCK is not so fast (flip flop buffers).

Finally, you can verify the data written to tape (if you used the adabas utility to copy the data or have written it direct to tape) by using the ADABCK READ_CHECK or ADAORD SIMULATE command.

Hope this helps.