Hi Arnt, Thanks for your reply. The example I quoted assumed that Wednesday was the first ever backup. I should have made that clearer, sorry.
Regards, John ## On 20 Mar 2014, at 14:30, Arnt Gulbrandsen <[email protected]> wrote: > That's not entirely how it works. > > On Wednesday, the tarsnap client needed to make a backup and started > computing the set of blocks needed for that. Some of those blocks had already > been uploaded, others it uploaded. > > On Thursday, the tarsnap client needed to make a backup and started computing > the set of blocks needed for that. Some of those blocks had already been > uploaded, others it uploaded. When it was done, it recorded the fact that > Thursday's backup was complete. > > Thursday's tarsnap invocation could not tell whether the already-uploaded > blocks were uploaded on Wednesday or earlier. It just knew that the blocks > were needed for Thursday's backup, and were present on the server since one > or more earlier backups needed them. > > (I'm lying very slightly.) > > Arnt > -------------------- John Gamble Senior Computer Biologist Cancer Genome Project Wellcome Trust Sanger Institute Cambridge, UK CB10 1SA Tel: +44 (0)1223 - 834244 Ext: 7703 [email protected] -- 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.
