Date: Fri, 11 Jul 2008 09:40:05 +1000 From: Mark Gladman <mark@legios.org> To: freebsd-geom@freebsd.org Subject: Re: Can GEOM be used to intercept the I/o calls to an existing mounted device? Message-ID: <200807110940.05862.mark@legios.org> In-Reply-To: <g55nc9$art$1@ger.gmane.org> References: <482257ad0807100541s2d2c3d1eo6cd57c3a1bc338d1@mail.gmail.com> <482257ad0807100655u1a5c660awfad05564e40e9a95@mail.gmail.com> <g55nc9$art$1@ger.gmane.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Friday 11 July 2008 05:19:35 Ivan Voras wrote: > Tapan Chaudhari wrote: > > Can't I do it on the fly while the device is already mounted? I just want > > that all the calls going to the device "/dev/md0s1" first come to me and > > then it goes to the original device. In short intercepting the i/o calls. > > Is there some way I can achieve this? > > It would be very nice if GEOM could do this, since it would then > trivially allow things like data replication, log/rollback, etc. but it > doesn't work like that. In short, no, you cannot listen to IO between > providers. > > (not that it isn't possible to do at all, it just isn't implemented). Whoops - I was *totally* focussing on the wrong part of his question... (It was late, that's my excuse. :)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200807110940.05862.mark>