Date: Thu, 13 Jan 2011 10:07:32 -0500 From: Boris Kochergin <spawk@acm.poly.edu> To: Alexander Leidinger <Alexander@Leidinger.net> Cc: freebsd-stable <freebsd-stable@freebsd.org>, Chris Forgeron <cforgeron@acsi.ca> Subject: Re: ZFS - hot spares : automatic or not? Message-ID: <4D2F1534.7010500@acm.poly.edu> In-Reply-To: <20110113154249.12101reh2to1rqe8@webmail.leidinger.net> References: <4D228F41.7040403@langille.org> <4D23504D.8060103@libeljournal.com> <4D2BD0A7.9060003@langille.org> <4D2C810E.2070007@libeljournal.com> <BEBC15BA440AB24484C067A3A9D38D7E0149F32D3484@server7.acsi.ca> <4D2E4C61.80407@acm.poly.edu> <20110113154249.12101reh2to1rqe8@webmail.leidinger.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On 01/13/11 09:42, Alexander Leidinger wrote: > Quoting Boris Kochergin <spawk@acm.poly.edu> (from Wed, 12 Jan 2011 > 19:50:41 -0500): > >> On 01/12/11 19:32, Chris Forgeron wrote: > >>> Solaris runs a separate process called Fault Management Daemon (fmd) >>> that looks to handle this logic - This means that it's really not >>> inside the ZFS code to handle this, and FreeBSD would need something >>> similar, hopefully less kludgy than a user script. >>> >>> I wonder if anyone has been eyeing the fma code in the cddl with a >>> thought for porting it - It looks to be a really neat bit of code - >>> I'm still quite new with it, having only been working with Solaris >>> the last few months. > > It depends upon a lot of standardized kernel notifications. Basically > (big picture view) it is the same as our devd (reacting to events) > with some logig what to do with it (which we can do without our devd > too). > >> Would the people with custom hot-spare scripts, or nothing automated >> at all, be content if the sysutils/geomWatch program grew support for >> hot spares in a future version? I already became somewhat familiar >> with the userland ZFS API when I added ZFS support to it. > > I had a look at geomWatch and it seems it is polling based. For > something like zfs hotspare replacement you normally want to have the > reaction event based (= devd). I even go further and think that things > which geomWatch is doing, should be done with devd (may it be > directly, or by delegating some events via a non-existing-yet > interface (which could be even script driven) to another daemon). It > may be that this would need some more events to be produced by > different geom parts. > > IMO it would be great if those people with hotspare-scripts would > publish them. This way a joined effort could be initiated to come up > with some generic way of handling this which could be included in the > base system. > > Bye, > Alexander. > Did a little research. In at least the ZFS case, it appears that events are available through devctl(4) and are therefore accessible through devd: http://2007.asiabsdcon.org/papers/P16-paper.pdf - section 3.7 -Boris
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4D2F1534.7010500>