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Re: [SLUG] HOT SWAPPING - back to the OP ;-)




Daniel Pittman wrote:
david <david@xxxxxxxxxxxxx> writes:
Daniel Pittman wrote:
david <david@xxxxxxxxxxxxx> writes:
(Admittedly, the last is only on really bad hardware, but hey, that
hardware is out there and still within the reasonable life of machines
for home users.)

Anyway, once the hardware doesn't die completely you still need the
driver stack to notice and remove the now absent hardware from the
software "shadow" representation.
Crap controllers are just that - crap ;-)
Returning to the original inquiry, and now that I know that I have a
82801GB/GR/GH (ICH7 Family) SATA IDE Controller (Intel) How do I go
about finding out if it's safe to hot-swap?
Did you try the libata status report page I posted the link to a while
back?  That should confirm that your ICH7 supports hotplug.

http://ata.wiki.kernel.org/index.php/SATA_hardware_features

When you posted I didn't know which controller was in there, now I do.

Chip		Driver		NCQ	DMA++	hotplug		PMP
ICH7 family	ata_piix, ahci	AHCI	AHCI	AHCI		no

Since I still don't want to fry the drive, the question still remains
(for me at least, given that I'm not as erudite as some).... Will this
hotplug??

Yes, if you are running it in AHCI mode.  Specifically, you have to be
in something other than "compatibility mode" in the BIOS, and it has to
identify as an AHCI controller during boot.

Check the kernel messages after boot to confirm that:

    dmesg | grep -i ahci



Nothing in dmesg. As far as I can see, nothing in BIOS :(

This seems to suggest that hot swapping this particular configuration is a bad idea. And yet Gnome was telling me that I could remove the media. Is this a bug?

Unfortunately, hardware specifications tend to tell you what a BIOS/Controller/MB *has*, not what it doesn't have. Which means that for people like me, it comes down to

* asking in expert forums (like SLUG?)
* guess and hope for the best
* do nothing.

Not being able to hot-swap for me is mostly an inconvenience rather than a disaster, but I recently had an emergency situations where I would REALLY liked to have been able to hot swap.

regards,

David.

PS: the technical discussion about hot-swapping is fascinating, but I would still like to solve the immediate problem.