[GLLUG] Hot Swap an ATA Hard Drive -Another Approach

Gary Holbrook gholbrook@voyager.net
Wed, 19 Feb 2003 16:40:02 -0500


Some of the external enclosures are made for internal CDROM drives, which
should mean that they'll fit a drive cage quite effectively.

While the idea isn't as nice as high end hardware, it is economical...and
would provide for mirroring important data.  I actually contrived this
notion whilst wallowing in thorough disgust at a slew of drive problems that
I had.  Backups become a problem because the tapes frequently cost nearly as
much as a second drive would.  This idea permits drive swapping with really
cheap hardware without rebooting...using some of the fabulous scripts you
guys posted earlier.

----- Original Message -----
From: "Matt Graham" <danceswithcrows@usa.net>
To: "gllug" <linux-user@egr.msu.edu>
Sent: Wednesday, February 19, 2003 4:08 PM
Subject: Re: [GLLUG] Hot Swap an ATA Hard Drive -Another Approach


> On Wednesday 19 February 2003 15:27, after a long battle with
> technology, Gary Holbrook wrote:
> > I've always wanted to try this with vanilla drives and cheap cages:
> > Get a 5 1/4 inch external USB enclosure and mount one of the
> > swappable cages in it.  Then you could use vanilla IDE drives and use
> > the usb enclosure to make them hot-swap.
>
> I don't think this'd work the way you want it to.  The "swappable cages"
> you refer to *will* make an IDE drive hot-swappable, so long as you run
> the script Jeff mentioned earlier (on BSD) or the script I mentioned
> earlier (on Linux) when swapping drives.  USB 1 is too slow for disks,
> while USB 2 is better, it's still slower than a direct IDE connection.
> You'll still have to rescan the SCSI bus using a script if you change
> the drive without unplugging the USB device.  Not to mention that the
> IDE hot-swap cages you refer to may be too big (many are meant to fit
> in a 5.25" bay) to fit into the external USB disk enclosures (meant to
> take 3.5" disks), and weird hardware interactions between the IDE
> hotswap cage and the USB disk enclosure could take place.
>
>
>
> --
>   "Bother," said Pooh.  "Eeyore, ready two photon torpedoes and lock
>   phasers on the Heffalump; Piglet, meet me in transporter room three."
>      --Robert Billing
> There is no Darkness in Eternity/But only Light too dim for us to see
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