On Tue, 26 Nov 1996 12:45:35 +1300, Dianne Sharp wrote:

>I have been doing some comparisons between ADSM and our current backup
>software, Arcserve.  It appears that in some cases the data transfer
>rate (i.e. KB per second) is significantly faster with ADSM.  However,
>the elapsed time of the backups in some cases is longer.

>Can someone please explain this.  Is the extra time attributed to ADSM
>updating its database, expire files, etc ?

I think part of the answer has to do with how ADSM computers KB/Sec.
It seems that ADSM only computes KB/Sec for the time during which it
is sending data from the client to the server. They do not account
for things such as the time it takes to scan a directory. Lets take
an example of an incremantal backup which will only find 1 file which
is 500K. If it takes ADSM 1 hour to scan your HD, but only 1 sec to
transfer the file then your KB/Sec is 500K and your backup was 1 hour
long. When compression is enabled the numbers are even more
misleadding.

>Does anyone know if there is a way of improving this?

I think I read somewhere that incremental by date was faster, but I
have never had the need to use it so I don't know much about it. You
should also look at your DB cache hit rate. If it is below 99% then
you need to increment the DB buffer pool size. With the logs check
for the wait time if greater than 0 then you need to increase the log
buffer pool size.