On 10/29/14 11:44, Elvis Stansvik wrote: > I just signed up for Tarsnap and I'm very pleased with the service. It's a > weight off my shoulders to finally have both my laptop and my small FreeBSD > server backed up somewhere. Many thanks to Colin for the nice design of the > system and the simple tar-like interface.
:-) > Short question: When extracting a small (few KB) file from a somewhat big > archive (15 GB or so, with quite a number of files), what is it that takes > time? For me it took ~4-5 minutes to get such a file out. > > It's not a problem at all since this is something I hope to never have to do, > but I was just curious what is the actual bottleneck. I'm guessing it's the > downloading, decryption and scanning of the tar header? You're exactly right. Tarsnap stores the tar headers separately from the tar data in order to speed up this process, but there's still ~50-100 bytes (512 bytes of tar header, compressed) which needs to be downloaded per file so that tarsnap can decide which parts of the archive need to be extracted. -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
