First page Back Continue Last page Graphics

…Parallelism Test

Notes:

My tests showed that adding more channels than available devices increased elapsed time. The first test (script “two_channels.rman”) allocated two channels for two output disk devices. The elapsed time for the backup is 84 seconds (rounded). Backing up the same exact data using ten channels required 99 seconds, an 18% increase in elapsed time.
Note that these tests were run on a server dedicated to RMAN testing; no other processes where active. The specifications of the my test environment are:
Dell Poweredge 2400, 1 Pentium 733 Mhz CPU
Linux OS (Red Hat, 8.0)
Oracle9i (9.2.0.4)
The input devices are three 9 GB Seagate Cheetah disk drives, tied with RAID 0, 40MB/second transfer rate
The output devices are two 36 GB Seagate Cheetah disk drives, 40MB/second transfer rate
One Quantum (Benchmark) DLT1 tape drive, 40GB cap, 80GB compressed, sustained transfer rate 3MB / second (6MB compressed), burst transfer rate 20MB / second.