Re: [Evms-devel] Re: [ANNOUNCE] EVMS Release 1.1.0-pre1

[Steve D. <st...@us...>]

On 06/09/2002 at 10:11AM, Jeremy Jackson wrote:
> First, let me say I'm a huge fan of EVMS.  This is a really forward
> thinking architecture, just what Linux needs.

Thanks for the vote of confidence.

> I'm particularly interested in seeing a feature of snapshotting,
> where a read write snapshot can be made, the filesystem mounted
> (currently needs a kernel patch, but that's ok), and then modified
> as a staging or prototype.  Once the changes are completed, the magic
> feature allows the snapshot changes to be copied back to the original.
> This would allow atomic updates, for example, with rpm -Uvh or
> similar.  Can you describe what the new snapshot feature listed
> below does in more detail?  Where can I read about this?

The snapshot code in the 1.1.0 pre-release contains both the function for
writable snapshots and the function for rolling back a snapshot (put the
contents of the snapshot back on the original volume).  Using both of these
functions should get what you want.

I just tried this on the pre-release code.  I created a writable snapshot.
I wrote new data to the original volume.  I wrote different data to the
snapshot.  Then I rolled back the snapshot.  I found a bug in the snapshot
kernel plug-in, but once I fixed that the original volume came up with the
new contents of the writable snapshot.  The fix should be in the next
release of the code.

Steve D.