(Semi)hot swap IDE

Toomas Aas toomas.aas at raad.tartu.ee
Sun Nov 23 03:17:14 PST 2003


I wrote:

> >If the majority is right and IDE drives cannot be hot swapped, this
> >would indicate that we would need to power down the machine every time 
> >we want to change the backup HDs. This would be less than 
> >perfect, but since we are cheap we could live with it. 

> >OTOH I read 'man atacontrol' and saw that there are commands like
> >'atacontrol detach' and 'atacontrol attach' which seem to be meant 
> >for detaching/attaching IDE devices while the machine is running. 
> >Does this mean that I could actually run 'atacontrol detach <channel>', swap the
> >drive and then run 'atacontrol attach <channel>' and be able to use
> >the second HD after that? Is anyone doing something like that?

To which Scott W replied:

> I dislike IDE and tend ot avoid it like the plague when possible, 

Me too.

> but:
> 1.  The 'generic' removeable drive trays for IDE that use a normal IDE 
> controller (like attaching to the slave or secondary channel on most 
> onboard IDE), with another disk or device attached that's being used, do 
> not support removeable devices.  It's _extremely_ likely that you'll 
> hang the IDE bus.

If there is only CD-ROM (which is almost never used) attached as 
primary master and the removable disk attached as secondary master then 
maybe I don't need to worry too much about that.

> 2.  Having mentioned #1 already, it's _possible_ that using a secondary 
> controller (unsure if this can be the second channel of onboard or not, 
> but NOT simply the slave of a given channel with another device), and 
> atacontrol, it appears (no, I have not tried this), you can bring the 
> controller itself (or channel?) offline, attach or remove the drive, and 
> then reattach it.  I'd like to hear more details on this one myself, and 
> may have a system I can test it on if I get too bored, but have long ago 
> chucked my IDE trays..

I'll probably be forced to do some testing on this during next few 
weeks. I'll keep you posted on the results.

Toomas Aas | toomas.aas at raad.tartu.ee | http://www.raad.tartu.ee/~toomas/
* Life ain't fair, but the root password helps.

More information about the freebsd-questions mailing list