Hi The new release of shared snapshots can be found here: http://people.redhat.com/mpatocka/patches/kernel/new-snapshots/devel/ It has the interface we talked about on Linux Tag. So look at it as a last chance to review the interface. And also test it. To create a snapshot, you have to: - send a message - ask for status, get the snapshot id - suspend (this creates the snapshot, when the filesystem is quiescent) - resume Then, you can attach the snapshots by loading "multisnap-snap" target. If the table line contains argument "sync-snapshots", it synchronizes the snapshot list against what is given on the table --- i.e. creates snapshots that are on the table but are not in the store and deletes those that are not in the store but are on the table. Other changes: - make more structures private (move them to dm-multisnap-private.h), so that ABI doesn't change if these are chaged. - snapshot IDs are treated as strings, not numbers. - metadata cache size can be specified as an argument to the "mikulas" exception store. - an argument "preserve-on-error" that says that on error or overflow, writes to the origin should be disabled. - if you don't specify this, the origin continues operation, but snapshots are irreversibly damaged by this (use for non-important snapshots such as backups) - if you specify this, the data are always preserved, the whole thing just halts on error (user when snapshots contain some important data. - fixed two bad bugs in dm-bufio. Known bugs: - that read-vs-realloc race (that I already fixed in the old snapshots a year ago) is present there. I'll fix it, but it isn't so trivial as in unshared snapshots. Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
