On Tue, Jul 30, 2013 at 06:13:48PM -0500, Brooks Davis wrote: > On Tue, Jul 30, 2013 at 10:19:54PM +0000, Rotate 13 wrote: > > On Tue, 30 Jul 2013 16:41:14 -0500, Brooks Davis <[email protected]> wrote: > > > > > On Mon, Jul 29, 2013 at 05:14:04PM +0000, Rotate 13 wrote: > > >> How to disable *all* GEOM tasting of newly-attached devices? I looked > > >> through the manuals, searched web, grepped sysctl -ad. I only find > > >> sysctl to disable all tasting for graid (kern.geom.raid.enable). > > >> > > >> Example, if I have removable drive I want to pop in and access from > > >> userland with open("/dev/foo0", O_RDONLY); without various GEOM > > >> modules first trying to understand. > > > > > > As far as I know there is no way to do this, but the existence of > > > partition tables shouldn't have any effect on your ability to open the raw > > > device as long as you haven't configured something in devd or similar to > > > open those partitions. > > > > Any pointer to look in sources for where triggers the tasting? I > > understand each GEOM has the taste code of its own... but something > > must start it all when device is inserted. > > The creation of a geom provider triggers the tasting. I suppose you > could create a new driver to matches the device preferentally to umass > or what ever device it normally attaches it and provides a simple node > for it. That sounds like a lot of work and you haven't explained why > you can't just let the tasting happen and ignore any partions that are > found.
If you use ZVOLs and snapshots you can easly end up with thousands GEOM providers, which doesn't scale well. Giving them all for tasting to all available GEOM classes will take a while too. In Illumos ZFS /dev/ entries for ZVOLs are lazy created - when someone looks up the given entry ZFS is noticed and corresponding entry is created. This was not always the case. Earlier they were creating /dev/ entries for all ZVOLs, but apperently they found it problematic. I remember this, because it took me a while to bring back non-lazy creation of /dev/ entries for ZVOLs. GEOM doesn't support anything like that. -- Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://mobter.com
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