Dear Colin, Thanks again for your reply. Still slightly confused about this process though…. In the scenario I'm thinking about, 'backup-wednesday.part' and 'backup-thursday' wouldn't have any common files (or blocks of data). The complete archive would be the sum of 'backup-wednesday.part' and 'backup-thursday'. Therefore, how is it possible to delete 'backup-wednesday.part'? Is it, in fact, impossible to do so in this case? If so, is there any way to create a single complete backup/archive from two or more partial ones, that were formed by premature termination of a backup.
I'm asking all this because given the speed of my upload connection, I know that I'll have to stop the initial backup before it completes. Just wanted to make sure that I'll ultimately be able to create a complete backup. A couple of minor queries: 1). To terminate an ongoing backup, is the command ^Q? 2). While the backup is ongoing, is it OK to use the computer as normal? Thanks again and apologies for the continued questions. Regards, John Gamble ### On 20 Mar 2014, at 22:23, Colin Percival <cperc...@tarsnap.com> wrote: > Hi John & list, > > On 03/20/14 07:21, John Gamble wrote: >> a). The archive 'backup-thursday' will contain only those files not present >> in >> 'backup-wednesday.part' > > Sort of. The Tarsnap service doesn't have any concept of "archives". When > you > create backup-thursday, tarsnap will upload the blocks of data needed by > backup-thursday which are not present in earlier archives. > >> b). If I delete 'backup-wednesday.part', then all the files necessary to >> create >> the complete backup (in this case, all the files) will be retained and >> transferred to 'backup-thursday'. So 'backup-thursday' is now a complete >> backup. > > There's no "transferring" going on; but tarsnap will only delete the blocks > which are used by the deleted archive and not by any of the archives you're > keeping. (Keeping track of this is what the cache directory is for.) > >> c). To delete 'backup-wednesday.part', the command would be 'tarsnap -d -f >> backup-wednesday.part'. > > Correct. > >> The reason I'm querying this is that you mention >> something about having 'delete keys'. Could you clarify this please? I >> don't >> see anything about a requirement for that on the Tarsnap general usage page, >> in >> the section relating to deleting archives. > > When you create a set of keys using the tarsnap-keygen utility, you get a key > file which has all of the keys for that machine. But you can use the > tarsnap-keymgmt utility to create a key file which has only a subset of keys, > e.g., > one which can be used to create archives but can't delete them. > > But that's "advanced usage" and not something you need to worry about at > first. > > -- > Colin Percival > Security Officer Emeritus, FreeBSD | The power to serve > Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid > -------------------- John Gamble Senior Computer Biologist Cancer Genome Project Wellcome Trust Sanger Institute Cambridge, UK CB10 1SA Tel: +44 (0)1223 - 834244 Ext: 7703 j...@sanger.ac.uk -- The Wellcome Trust Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE.
