Just to come back on the point regarding NFS versus iSCSI: - proprietary systems like IBM's, HP etc. are both expensive and complicated. This violates our 'simple problems' mantra as well as having cost implications. - our IaaS platform has an open software layer with sole root access granted to the user. That has huge security and privacy implications for our users i.e. they have access to their data, we as a vendor don't (except for physical access which is highly restricted and monitored). It means we see customer drives as block storage devices. We can't see their file systems. NFS can we implemented by a customer on top of our platform but not by ourselves. We do in fact have many users of NFS in our cloud. Its our job to manage the storage at the block device level. As a vendor we are a 'pure IaaS' provider. We don't reach into the software and networking layers wherever possible. Its a fundamentally different approach giving our customers the same sort of control over their computing as they would with a dedicated set-up. - DRBD has de-duplification. For a public cloud like ours this will save us a lot of space, more than the replication introduced. Why? We just RAID6 already so replication won't be higher with DRBD (we will swap RAID6 for DRBD). We have thousands of identical operating systems running concurrently with their own distinct copies (each of our cloud servers is a complete stand alone OS on its own block device, again for privacy/security reasons).

So, we believe that a move from our current set-up to distributed block storage will actually REDUCE costs overall no increase them. We will of course have the added convenience and elimination of single points of failure in storage that distributed block storage entails.

Best wishes,

Patrick CEO CloudSigma