On Wed, Sep 13, 2006 at 09:14:36AM -0700, Frank Cusack wrote: > > Why again shouldn't zfs have a hostid written into the pool, to prevent > import if the hostid doesn't match?
See: 6282725 hostname/hostid should be stored in the label Keep in mind that this is not a complete clustering solution - only a mechanism to prevent administrator misconfiguration. In particular, it's possible for one host to be doing a failover, and the other host open the pool before the hostid has been written to the disk. > And why should failover be limited to SC? Why shouldn't VCS be able to > play? Why should SC have secrets on how to do failover? After all, > this is OPENsolaris. And anyway many homegrown solutions (the kind > I'm familiar with anyway) are of high quality compared to commercial > ones. I'm not sure I understand this. There is no built-in clustering support for UFS - simultaneously mounting the same UFS filesystem on different hosts will corrupt your data as well. You need some sort of higher level logic to correctly implement clustering. This is not a "SC secret" - it's how you manage non-clustered filesystems in a failover situation. Storing the hostid as a last-ditch check for administrative error is a reasonable RFE - just one that we haven't yet gotten around to. Claiming that it will solve the clustering problem oversimplifies the problem and will lead to people who think they have a 'safe' homegrown failover when in reality the right sequence of actions will irrevocably corrupt their data. - Eric -- Eric Schrock, Solaris Kernel Development http://blogs.sun.com/eschrock _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
