ntbackup forcing or checking for Hardware Comp.

[Rowan]

I'm using the following command line to schedule backups. Everything works
except the drive fills up at 40Gigs, compressed the drive holds 80 Gigs. Is
there a way through windows to see. a. If the device supports compression in
windows eyes. or b.how to force compression. I cant' find enough info in the
event logs to tell me what is happening. Also where does ntbackup for 2000
save yoru backup log ?

ntbackup backup "@c:\studio_3.bks" /P "DLT" /N "Studio 3 Backup %DATE%"
/V:no /R:no /L:s /M normal /RS:yes /HCn /UM

 

[Pegasus \(MVP\)]

Your backup device may not support data compression.

Log files are kept in your profile folder. Look for files
with a .log extension.

 

[Enkidu]

I'm using the following command line to schedule backups. Everything works
except the drive fills up at 40Gigs, compressed the drive holds 80 Gigs. Is
there a way through windows to see. a. If the device supports compression in
windows eyes. or b.how to force compression. I cant' find enough info in the
event logs to tell me what is happening. Also where does ntbackup for 2000
save yoru backup log ?

ntbackup backup "@c:\studio_3.bks" /P "DLT" /N "Studio 3 Backup %DATE%"
/V:no /R:no /L:s /M normal /RS:yes /HCn /UM

You don't say what brand of drive you use. Most drives do hardware
compression by default, others can be set to do hardware compression
by setting DIP switches. Usually they are set that way by default.

I presume you are using 40/80GB tapes? The best compression you can
expect on , eg DAT drives, is about 1.7. I would expect you'd get
about 60 - 70 GB of data on there. A compression ratio of 2.0 is a
theoretical maximum.

You say that the drive fills up at 40GB. How do you know this?

NTBackup for Windows 2000 saves the backups in C:\Documents and
Settings\<username>\<some number of directories down> If you do a
search for backup*.log in C:\Documents and Settings you should find
the actual location. Sorry, it has too many levels to be easily
remembered, and the Username may vary! Most times it is
"Administrator".

Cheers,

Cliff

 

[Guest]

Keep in mind that compression only works on files that CAN be compressed....
..jpg files for example, or .vob cannot be compressed by backup
Are your files compressable ?

 

[Rowan]

You don't say what brand of drive you use. Most drives do hardware
compression by default, others can be set to do hardware compression
by setting DIP switches. Usually they are set that way by default.

The system is a Dell 1600SC which has a DLT 110T VS80 yes the drive
supports compression. I have an identical drive in a 2400 server which works
great but that swith NT. the content of teh data is primarily cad files
basically vector graphics so very compressable. As for how I know well when
I check the back up dialogue box it shows how much data has been processed.
Right at 39,855,000 it asks for another tape.