On Sun, May 04, 2014 at 08:31:38AM +0800, lhmwzy wrote: > In hammer1,the target of hammer-mirror must be a hammer pfs slave,which > means that the target can't be mounted and lived show the source hammer > pfs master changes. > For example,if the hammer pfs master is down,the mirror hammer pfs > slave will not online automaticly which like a cluster filesystem will do. > > I read the hammer2 design document and find that hammer2 can do this,am > I correct? > > All things I want is hammer-mirror run between many hammer pfs, each > hammer pfs can be mounted with read (and write) mode while a ongoing > hammer-mirror. > > Sorry for my bad english.I wish you could understand what I have say.
You can only access a PFS slave in read-only mode. You have to upgrade (hammer pfs-upgrade) a PFS slave to a PFS master to also allow read-write access. But then you cannot use mirror-copy to update this master PFS. The hammer mirror-copy works only from one PFS master to many PFS slaves. But you can use mirror-stream to continuously update your PFS slave from you PFS master, while at least the master is in use. Automatically replacing a going down PFS master with one of its PFS slave might be possible, but this will manual work. I don't know if there is a out-of-the-box solution. In hammer2 this might change (I did not follow the latest changes in the development), but AFAIK hammer2 is still under heady development. Sven
