I've just completed testing the "deduplication and compression without an
account" suggested on the FAQ page (results below). I wanted to test
performance and see how deduplication would effect the ultimate amount of data
that would be uploaded.
The process took about 8 hours, with fairly intense CPU usage and disk IO. Is
this dry-run considered representative for a typical backup session? In other
words, will tarsnap take 8 hours (discounting the time to actually do the
uploading) to discover what files need to be backed-up, every time? If so, my
plan to run it hourly is hopeless.
The printed results show "new data, compressed size" is "245 GB". Is that value
before or after the magical de-duplication that is to be expected? Will my
monthly fee (at least initially) be approximately 245 * $0.25 = $60/month?
When I read that it’s “possible to store ‘archives adding up to several
terabytes’ while paying less than $10/month” I initially assumed the
deduplication compares my data with that uploaded by someone else (so my
"Rembihnútur.mp3" isn't uploaded, if another tarsnap user has already uploaded
"Rembihnútur.mp3"). But that’s not possible, because deduplication is only
per-account-key. Then I assume my pricing estimate above is accurate, and
tarsnap is a high-end service that is not priced for consumer use. =(
Regards,
Quinn
-------------------
[quinn@macbook] tarsnap --dry-run --print-stats --humanize-numbers -c
--exclude=Films /Users/quinn
tarsnap: Performing dry-run archival without keys
(sizes may be slightly inaccurate)
tarsnap: Removing leading '/' from member names
tarsnap: SystemKey: could not open file: Permission denied
Total size Compressed size
All archives 270 GB 251 GB
(unique data) 262 GB 245 GB
This archive 270 GB 251 GB
New data 262 GB 245 GB
tarsnap: Error exit delayed from previous errors.
