On 2020-03-24 13:30, JT Morée via tarsnap-users wrote: > Hi, > I am curious about the implementation details moving data though tarsnap. > I realize that I can dig through the source code but it was a bit obtuse when > I looked. I didn't see an answer to my question in the tips, faq, technical > details, etc. > > Does tarsnap write data to disk as it creates and encrypts chunks? If so, > where?
No. Tarsnap writes data to its cache directory when it creates archive snapshots and at the end of creating an archive, but there's no temporary storage. > If not, does it stream the chunks directly to the backup servers? In this > scenario I'd guess that data moves from disk through ram then across the > network. Yes. Chunks are generated in memory, compressed, encrypted, and signed, and then uploaded to the server; typically there's < 10 MB of data "in flight". (If there's too much waiting to be uploaded, tarsnap stops reading data from disk until the network catches up.) -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
