Re: Does anyone want key-resistant tamper-evident archives?

[Arthur Chance <freebsd@qeng-ho.org>]

On 08/09/2016 11:12, Arnt Gulbrandsen wrote:
> Thomas Tempelmann writes:
>> Is that just a question of manpower or is there an algorithm problem
>> that's hard to solve? Or is it just the fact that the bandwidth to the
>> server is limited?
> 
> Restoring is much too slow to be explained by bandwidth. My worst
> restore took several days and used less than 1% of available bandwidth.
> 
> Single-file restores are fast (at least fast enough not to irritate me).
> I think the problem is that that requests aren't pipelined. The client
> asks for a file, the server retrieves the file from the storage backend,
> the file is transferred, the client writes it to the file system, the
> client thinks about what file to ask for next, GOTO 1. If you're
> restoring half a million small files the network connection will be idle
> a lot of the time.
> 
> Life is much better if you restore a single big file (and even better if
> you don't have to restore).

A question for Colin: would it be possible for tarsnap to have a faster
restore mode where it simply created an unencrypted tar file on the
client equivalent to a given tarsnap archive, to be restored from as
necessary, or does the architecture preclude it? That would at least
speed up full restores after a crash that lost everything.

-- 
Schrödinger's cat had 18 half lives.