Label question...why does ufs label vanish on mount?

[Stefan Bethke]

Am 13.10.2010 um 06:56 schrieb Andrey V. Elsukov:

> On 12.10.2010 22:51, Kevin Oberman wrote:
>> For some reason the /dev/ufs/label entry that geom creates for every UFS
>> formatted partition is deleted when the device is mounted. This is not
>> the case for other file systems, though I have not tried them all. It
>> makes the drive much harder to deal with when you have to keep track of
>> which physical drive contains the labeled media. It is a particular
>> issue for hald and the tools which depend on it.
>> 
>> Is there a good reason for this odd behavior of UFS? If there is not a
>> good reason, could it be changed?
> 
> When you are opening provider for writing (i.e. mount FS) GEOM(4)
> initiates SPOILING and all consumers that are attached to this provider
> except one will self-destroyed. When you are closing provider GEOM(4)
> initiates TASTING and consumers can return back. Look at man 4 geom
> for details.

That explains the mechanism, but not the rationale.  Or is it just an unintended consequence?  And how is da2p1 different from ufs/mylabel?  (Mount da2p1 and ufs/mylabel is removed, but not the other way around.)


Stefan

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Stefan Bethke <stb at lassitu.de>   Fon +49 151 14070811