[Talk] Reality check...

Luke Mewburn lukem at wasabisystems.com
Wed Sep 11 14:35:16 EST 2002

On Wed, Sep 11, 2002 at 01:40:25PM +1000, Steve Jenkin wrote:
  | I had a thought & wanted a Reality Check on it.
  | It seems too obvious not to have been thought of before, so what's the
  | catch??
  | IDEA:
  | The cost of DLT & LTO tape media is ~$3/Gb.
  | The cost of commodity IDE drives is ~$1-2/Gb.  IDE enclosures with
  | either Firewire or USB are cheap & readily available.
  | Why aren't people moving away from tape media to removable IDE drives
  | [and treat them just the same way as tapes.  Normally kept on a shelf!]
  | Fulfills 'Cheaper, faster, better'...
  | What am I missing here??  Anyone heard of this being done?

A collegue of mine and I have discussed this exact issue.

The current thought is:

	* Use our existing smaller tape (or cd-r or whatever) for
	  nightly backups of really important stuff (/home)

	* Use external disks in firewire sleds (or other hot-pluggable
	  technologies; in 3-4 months serial ATA will become much more
	  prevalent and that supports hot plug), and back up the data
	  classified as "I need a backup of this on a semi regular
	  basis because it's a pain to get again" (pictures, software,
	  movies, etc).  Use large capacity 5400rpm disks for this.
	  Take the hot plug sleds+drive and put them in a secure

A 100GB disk + infrastructure (external sled) is now cheaper than a
100GB tape + drive ($6K - $10K).  I use `raw' figures in capacity
because gzip can compress better than a tape drive...

Disk advantage:
	* now cheaper/MB
	* random access

Tape advantage:
	* smaller physical footprint (over drive + sled)
	* slightly more resiliant, although you really don't want to
	  drop DLT tapes either.

This all said, I haven't deployed this myself.  I'm still backing up
my primary personal data nightly onto a 12GB DDS-3, and my "media"
partition less regularly onto other disks and 20GB DDS-4.  I do want
to move to this idea though.

Luke Mewburn  <lukem at wasabisystems.com>  http://www.wasabisystems.com
Luke Mewburn     <lukem at netbsd.org>      http://www.netbsd.org
Wasabi Systems - NetBSD hackers for hire
NetBSD - the world's most portable UNIX-like operating system

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