RE: remove-single-device removes mounted HDDs (kernel 2.6)

[James Bottomley <James.Bottomley@SteelEye.com>]

On Thu, 2005-08-11 at 11:51 -0400, Salyzyn, Mark wrote:
> The problem with pushing this policy to the user is that software
> applications have no means to determine that a device is currently
> in-use. For instance, the net result of pulling a device on a mounted
> filesystem is an eventual kernel panic.

The kernel only panics if you told it to with the mount option
errors=panic (or if you have errors=panic set in the superblock flags).

For file systems on removable devices you shouldn't be telling it to
panic on error, you should be telling it to continue or remount-ro.  If
you do this then you can happily yank the undelying device on a mounted
fs, which was one of the design goals of the 2.6 SCSI state model and
refcounting reworks.

James