[clue-tech] "rewindable" drive?

[David L. Willson]

Thanks all!

Nate:    No, there's not a significant amount of politics involved, and for the little there is, we all like each other, and they trust me, so they generally do as I ask.  That said, there are some pretty stringent requirements, and the risks that come with a customized version of using a well-known PHP app.  The website must not go down.  If it goes down for any reason (hardware, software, human oops or human evil), it must come back up in 5 minutes, with the database at it's last consistent state.

Angelo:  I'll be evaluating ZFS versus LVM's capabilities.  I can do quite a bit because it's an Ubuntu LAMP Server virtualized on a full Ubuntu Server, so the "getting underneath" it is there in spades.

Dave:    Yes, I have a gold image.  Every night, I "pause" the VM and rsync it off to another box, which rsync's it off to an external drive, which is rotated monthly.  I'm looking for the fine-grained online backups, "an hour ago", "two hours ago", "a day ago", "two days ago", and "a week ago".  Currently, I can only offer "a day ago" and some further back at monthly levels of granularity.  My dream was to offer "anytime in the last 72 hours" or something like that.

Mike:    Let me know if you come up with something.  I'm just sure this can be done with our current technology; I guess nobody's bothered to write it is all.  I believe that Microsoft's Volume Shadow Copy does very nearly what I want, but of course, only for Windows.  I'll say again what occurs to me pretty often.  Microsoft should be on our side.

In conclusion, I'm pretty sure that LVM, ZFS, and/or VMware Server 2.0 named snapshots will get my 90% of the way there, at a fraction of the cost in disk space.

Any DRBD experts out there?  Want to help me set some stuph up?