On 2 May 2001, at 22:53, Mark Stapleton wrote:
>Where does the trade off happen for your system? There
>are so many
>variables that it is almost mandatory to do some
>benchmarking to find
>the breakpoint.
Questions like this are extremely complex. Every single piece in the
system must be looked at to determine bottlenecks and best solutions.
A partial list would include:
- size of files being backed up
- number of files being backed up
- rate that files can be read from disk
- read datastreams from the same disk
- rate that client can send data
- network topology between client/server
- rate that server can receive data
- concurrent data streams into the server
- tape drive speed (streaming, start/stop)
- buss speed to tape drive
- concurrent data streams for multiple tape drives
sharing a single buss
- compressability of data
- I/O capability of tsm server
- cpu speed of tsm server
Any one of these can be a bottleneck that destroys
backup performance. And no, there is not an easy way
to figure all this out. Probably the hardest thing I find
for myself is to not make assumptions. Every single piece
of the puzzle must be looked at!
Rick
