From Leo's mailbag:
> From: A Computer User
> Sent: August 20, 2007
> To: Ask Leo!
> Subject: backing up across the internet
>
> Leo,
> Following on from this week's focus on backups, my question is this - I
> look after an office with 20 PCs and a server, and we run weekly full
> backups and daily incrementals. Backups are to a USB-attached hard
> disk, which is taken off-site overnight. What I'd ideally like to do is
> carry out the backup process over the internet, to a remote PC with the
> backup drive permanently attached to it, to avoid physically
> transporting the drive. Full backup is around 120GB of data,
> incremental is 5 - 10GB. What would you recommend as the best method to
> achieve this? (using an internet hosted, paid-for backup service is not
> an option - too expensive!!)
The problem you'll run into is bandwidth. Unless you have an incredible
internet connection, the copy off-site will take longer than the period
I've done a little back-of-the-envelope math, and as you can see, a 120
gigabyte backup will take over a week to upload at "traditional" T-1
or good DSL speeds. If you have a VERY good internet connection - beyond
the maximum of DSL rates, you're still talking a day to upload and that's
assuming perfect communications and 100% use of the internet connection.
1.5Mbs (T-1, "good" DSL) 10Mbs (basic ethernet)
120gig 7.5 days 1.1 days
10gig 15.2 hours 2.2 hours
IMO: across-internet types of backups really only make sense if you've
got an *extremely* fast internet connection, or the amount of data
that you're backing up can somehow be constrained to a more reasonable
amount.
FWIW: I *do* what you're suggesting. I use Hamachi to create a VPN that
both local and remote machines are on, and then simply use Windows file
sharing and copy files between them. However it's most definitely a
limited set of data, and I do it only in the middle of the night when
both internet connections (local and remote) are otherwise idle.
Thanks for asking,
Leo Notenboom
Article 1646
| Category:
Internet
