Re: Initial backup of encrypted hard drive

[Colin Percival <cperciva@tarsnap.com>]

On 05/12/16 09:45, Rory Sutton wrote:
> I'm backing up my home directory (ubuntu 16.04) on the boot drive (a 232GB SSD
> with filesystem encryption (LUKS).  The volume has 30GB used.
> 
> The dry-run with tarsnap looked good, but when I started the actual backup I
> used -v in order to track progress.  For a day and a half now, it has been
> chasing the pair of symlinks that implement the stacked filesystem encryption
> giving screen output that looks like:
> 
>  home/.ecryptfs/rjs/.Private/ECRYPTFS_FNEK_ENCRYPTED.FWYFPOLMc6dcz-RcilQIh8jTj1im8fC9VKIL6Kz2fD6JUvC9o3c91YOtgU--/ECRYPTFS_FNEK_ENCRYPTED.FWYFPOLMc6dcz-RcilQIh8jTj1im8fC9VKILD5aOq9eum1NIxpJW00ZtF---/ECRYPTFS_FNEK_ENCRYPTED.FWYFPOLMc6dcz-RcilQIh8jTj1im8fC9VKILNgnLA6mMrefEow0ai.03Sk--/ECRYPTFS_FNEK_ENCRYPTED.FWYFPOLMc6dcz-RcilQIh8jTj1im8fC9VKIL-1SftWagtNSUkuskbt21G---
> 
> Checking the account activity, I've only accrued a very small cost for
> bandwidth, nothing for storage.  Am I:
> 1. in the midst of a disastrous recursional excursion
> 2. chasing my tail and not getting anything done
> 3. overthinking this, and should just chill?

I'm not familiar with ecryptfs, but I'm going with either (2) or (3) here,
since even if you managed to create an archive with many many copies of the
same data, tarsnap's deduplication will reduce that to a reasonable size.

That said, tarsnap will be more efficient if you run it against unencrypted
data, since that way it can compress your data before (re)encrypting it.

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid