backup qualifiers

[Marc Van den Broeck]

To copy a large file (4 Gb) from disc to disc, backup seems to be faster then copy. Are there qualifiers to speed up the copy or the backup process?

Thx
Marc

[Jeroen Hartgers_3]

$ backup

example

$ backup/log test.db -
dka100:[000000.dir1.dir2.dir3]*.*

the log qualifier will genarte the message:
%BACKUP-S-CREATED, created dka100:[000000.dir1.dir2.dir3]test.db

[Marc Van den Broeck]

Jeroen,

I guess using the log qualifier will not speed up the process?

Rgds
Marc

[Karl Rohwedder]

You could try different values of
SET RMS /BLOCK=? /BUFFER=?, but one limiting factor will be the fragmentation of the source disk.
For Backup see the various streams about backup performance.

regards Kalle

[Jeroen Hartgers_3]

the log qualifier will speed down but in this case with 1 file nor realy. if there is a lot of log output by examble een backup restore of a disk it will speeddown the back restore for a match time.

[Jeroen Hartgers_3]

that's right

[Jan van den Ende]

Marc,

You are DEFINITELY right! /LOG wil slow it down. For each file processed, an output line has to be constructed, and an extra IO must be executed to write that line to SYS$OUTPUT or the specified logfile.
But in this case, an operation on just one file, the effect is very minimal.

@Jeroen:

...
dka100:[000000.dir1.dir2.dir3]*.*


You are playing with matches in a gunpowder storage!
Specifying [000000... in a backup output string generates a toplevel 000000.DIR.
So far, no noticable problem yet, maybe for a long time
BUT, if you process this directory the same way again, you will have created 000000.000000.DIR
And NOW you are in for some fun!

Please, train yourself to NOT use the [000000.xyz syntax in output specifications!

fwiw,

Proost.

Have one on me.

jpe

Proost.

[Ian Miller.]

In VMS V8.2 and V7.3-2 patch kits the default block size for copy was increased to 127 blocks and this has helped copy performance.
The optimim value if using EVA is 124.
If you are not at these versions then use the SET RMS command to increase the default multiblock and multibuffer counts.
Try MBC=124 and buffer count=3 for a start.

[Marc Van den Broeck]

Jan,

my /log remark was ment a little bit sarcastic because the answer of Jeroen was not really answering my question (Jeroen, dont feel offended).
So, dont think nor talk about /log but about qualifiers speeding up the process ;).

Rgds Marc

[Galen Tackett]

/LOG will REALLY slow it down if you're using an old ASR33 or similar.
:-)