Expanding existing Hammer FS

Michael Neumann mneumann at ntecs.de
Wed Dec 17 15:53:58 PST 2008

Am 17.12.2008 21:20, schrieb Jonas Trollvik:
>>     It *IS* possible to probe the location of the HAMMER volumes 
making up
>>     a filesystem.  Each volume header has all the information needed,
>>     including the number of volumes, which volume number in the set that
>>     particular device is, the unique UUID (will be the same for all
>>     volume segments), and the label.
>>                                         -Matt
> What would happen if the disks would change device name, i.e. move the
> drives to a different controller ?
> Would it still be able to auto detect their locations?

In case of Hammer: YES. Each Hammer filesystem has a unique identifier
(UUID) plus a label (not neccessarily unique). This, together with the
number of volumes that make a filesystem, is present in each volume. So
we just have to scan all devices and gather these informations.
So it should be possible (yet not implemented :) to mount a Hammer FS by
label (if unique) or by UUID. Once this works, device names should
become pretty superflous (for the purpose of mounting).


More information about the Kernel mailing list