The right way to remove disk drive

[Damian Wiest]

On Wed, Feb 14, 2007 at 10:23:18AM -0300, Fernan Aguero wrote:
> +----[ Miroslav Lachman <000.fbsd at quip.cz> (14.Feb.2007 08:10):
> |
> | Hi all,
> | 
> | what is the right way to remove disk drive from running
> | system without 
> | reboot?
> | 
> | I have Sun Fire X2100 with 2 identical drives in gmirror.
> 
> [snipped]
> 
> | So what is wrong with manual removing drive?
> |
> +----]
> 
> To what Poul-Henning replied:
> 
> +----[ Poul-Henning Kamp <phk at phk.freebsd.dk> (14.Feb.2007 08:47):
> |
> | Not all ata controller chips actually support hot-plug.
> |
> +----]
> 
> And not all OSs support hot-plug even when the
> underlying controller chips might: as per the Sun Fire X2100
> release notes:
> 
> "SATA hot plug is supported only for the Windows XP Operating
> System (OS). If you wish to change hard disks with Linux or
> Solaris OS, you must reboot the system."
> http://docs.sun.com/source/819-3722-16/index.html#21924
> 
> So it's not only FreeBSD that's missing the 'feature'. I'm
> not an expert in low level hardware/driver issues at all ...
> but I wonder if this is because of the chipset drivers in
> each OS or because of the way the disk management framework
> works in each OS ...
> 
> Fernan

I can assure you that the X2100 does indeed support the hot plugging of 
disks.  Attempting to setup RAID on these systems would be pointless 
otherwise.  Okay, not pointless, but you'd have to take it out of service
to replace a failed disk.

I suspect that the Sun document you referred to is talking about hot 
plug of disks when using the on-board fake-raid chip.  ISTR there only 
being Windows drivers available, but perhaps Solaris drivers were 
released?

In any case, you don't want to use that chip if you're running Solaris; 
use SVM.  I _just_ tested detaching sub-mirrors, pulling the disk from 
the chassis and then replacing it.  Everything behaved as expected, 
including the automatic resync of metadevices associated with the drive.

-Damian

ps.  What are you doing reading the docs that came along with the 
     server? :)