Mozy Sucks
I used Mozy and it sucked.
Not fun when your PC boots, fails to mount a drive letter properly and then Mozy assumes that 30GB of data doesn't exist anymore and deletes it.
EMC has transferred its Mozy online backup service, assets and staff to VMware, signalling VMWare's intent to be far more visible as a cloud IT service provider. There is no mention of any acquisition or transfer fee, which might seem odd. Surely Mozy has a value as a business and surely EMC's market worth will be diminished …
I bailed out after they decided that they didn't want my business on the terms they'd sold it to me, and having uploaded ~400GB they would now want several thousand dollars a year. So I jumped, closed my account and moved to Crashplan. Took a few months to get the upload done, but their software offering is far better and their reliability is far better.
If you've got your "cloud" platform hosted by VMWare, and your backup hosted by Mozy (because of the favourable cost and tidy integration, see?), can you really be sure that they're taking responsible care of your data.
What if the live data and backups are in the same datacentre? You lose the datacentre (connection issues, power failure, flood, train crash, I don't know), and all your data is up in smoke. And of course this is the kind of area where they could save money by offering the backup as an add-on service.
I'd be wary...
"What if the live data and backups are in the same datacentre?"
The point of a global network of datacentres is precisely so the "backup" isn't in the same datacentre. Not only that, but the "live" data is redundant across multiple datacentres in the event of an outage. They likely split data/parity between the 3 or 4 datacentres closest to your location, so in the event of an outage, there's not a lot of data to push around to rebuild the "lost" information, or in the case of mirroring, much data to push to a new centre to maintain the mirror.
A single vendor then only becomes a problem if you're bound to their services (for whatever reason) and they "adjust" their fees and ToS (like Mozy did). Or if they go out of business (like Mozy might, however unlikely).
Got to love the Mozy website. Doesn't actually tell you anymore how much stuff you can actually backup. I suppose you have to give them your money before they give you the terms and conditions?
Neither the "Pricing" page or "Features" page mentions anything about storage limits.
Muppets.