Large file backup

Goal

Given a freshly created Obnam server with an empty chunk store, how long does it take for the Obnam client to back up a 1 GiB sparse file?

Steps

create a 1 GiB sparse file
- in shell: truncate --size 1G filename
create an empty chunk store and start the Obnam server
run the Obnam client, backing up the sparse file

Measure the duration of the backup command. That number is the benchmark result.

Obnam 0.4.0

Without flamegraph, wall clock time 7.4 seconds.

2021-10-10 run

Lars ran this on a Thinkpad T480 laptop with a SATA SSD.

Ran with and without cargo flamegraph. Time without is 7.8 seconds. The flamegraph shows that almost all the time is spent on sha256 checksum computation.

This is the baseline result, because it's the first result. The steps should be automated; the source tree has a bench.sh shell script that is a start.