On Tue, Jul 05, 2011 at 09:03:50AM -0400, Edward Ned Harvey wrote:
> > I suspect the problem is because I changed to AHCI. 
> 
> This is normal, no matter what OS you have.  It's the hardware.

That is simply false.

> If you start using a disk in non-AHCI mode, you must always continue to use
> it in non-AHCI mode.  If you switch, it will make the old data inaccessible.

Utterly not true.

Even in this case, the problem is not access to the data. The problem
is with booting from the device / mounting as root, because solaris
(and windows) embed device name/path information into configuration
data critical for booting. 

Even these OS's will be able to access data disks via either
controller mode/type if the boot time issue is removed.

Other operating systems that don't depend on embedded device path
information in the boot sequence can switch easily between IDE/AHCI
modes for boot disks, or indeed between other controller types
(different scsi controllers, booting native vs as a VM, moving disks
between boxes, etc).

The fact that Solaris fails to tolerate this is a bug.  In addition
to other problems, this bug manifests when trying to use removable usb
sticks as boot media/rpool, because usb device names are constructed
based on port and topology in some cases.  I have also been bitten by
it in the past when rearranging controllers into different slots.

> Just change it back in BIOS and you'll have your data back.  Then backup
> your data, change to AHCI mode (because it's supposed to perform better) and
> restore your data.

In this case, the recorded device path has probably been mangled, and
will need to be repaired before the pool is bootable again.  The pool
should, however, be accessible as data from an independent boot.

--
Dan.

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