TMG-L Archives

Archiver > TMG > 2003-03 > 1046555816


From: Dennis Lee Bieber <>
Subject: Re: [TMG] Backup media
Date: Sat, 01 Mar 2003 13:56:56 -0800
In-Reply-To: <010b01c2dfba$24dc1770$9c6a3b42@laptop>


On or about 22:16 02/28/03 a carrier pigeon from John Farmer delivered:
>The list addressed back ups a while back. I started putting photos in my
>project, and my last back up took 6 floppys and lots of time. I am hoping
>to put a lot of photos in my project (though not every will and census)
>and it is clear that soon floppies will not be an option. Will I outgrow
>CD roms also as a backup media? If so, I guess I will need to invest in
>an external gadget; a few were mentioned with kudos. Does anyone use a
>backup "service" with remote, automatic backups?

I hope you have DSL/Cable... If you outgrow a 650MB CD-R, just
think of how long it would take to transfer that data over a dial-up line.
Assume no other activity, so the dial-up is fully dedicated to just the
back-up. 56K modems only get that speed on downloads -- uploads are in the
28.8/31.5 range and typical compression of 2:1 through the modems.

28800 * 2 => 57600bps / 8 => 7200 bytes/second.

650 * 1024 * 1024 => 681574400 / 7200 => 94663 seconds => 1578
minutes => 26.3 HOURS

A complete back-up of my computer takes around 20 CD-Rs, and about
6-8 hours to perform. A monthly incremental back-up takes 1-2 CD-Rs and
about 30 minutes (the times don't scale nicely due to set-up, file marking,
and the difference between writing at 4X (8X drive, but the top speed is
only reached on the outer half of the disk) and reading at 16x (32X drive,
again top speeds are only obtained on the outer edges).

--
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> | Dennis Lee Bieber <
> PGP keys available | RSA keys preferred <
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