Re: [Duplicity-talk] Direct backup of LVM snapshot partitions?

[edgar . soldin]

On 10.12.2012 12:58, George MacKerron wrote:
> Thanks Martin, that's really helpful -- I'll investigate rdiff.
> 
> I guess an alternative feature that would support this use case might be 
> duplicity backup of data from stdin (possibly with a nominal file name)? Then 
> I could do something like:
> 
> dd if=/dev/blah | duplicity --stdin-data=devblah.img ...
> 
> In fact, the main thing I normally use duplicity for is backup of Postgres 
> pg_dump output, and it seems like this would be really useful there too 
> (avoiding a lot of disk space wasted on temporary files, and a lot of 
> thrashing the disk) -- i.e.
> 
> pg_dump … | duplicity --stdin-data=mydb.sql ...
> 
> But perhaps there are reasons this wouldn't work -- such as needing random 
> access to the data being backed up?
> 

duplicity reads the data blockwise as a stream. so theoretically you could 
extend duplicity to do a one "file" backup from STDIN . but that is some major 
work, as _all_ of duplicity's actions would have to be modified and you will 
have to work around the file attributes, which probably are not valid or 
existing for the stream.

having said that. the easiest would be probably shell scripting a solution that 
pipes eventually into gpg, if you really insist on having no physical file 
anywhere.

using snapshots seems the easiest way to go for your scenario to me though. you 
still haven't given a rationale not to use them. you risk backing up corrupted 
data if you simply dump the device, you realize that right?

ede/duply.net