I keep hearing how online Internet backups are the future for business and that the world has solved another check box of a technology challenge. I was talking with some people recently and ran through a couple of numbers. Let's take a small to midsize doctor's office with 8 TB of data. Say this office pays for high-speed Internet and gets 30 Mbits/sec upload and download. That translates to a raw packet performance of 3.75 MB/sec. Assuming packet overhead and no retransmits, I would say take off 10% so you get 3.4 MB/sec. For raw restore time for the whole system without compression and dedupe (more on this later) you would get (8*1000*1000*1000*1000) [disk terabytes]/ (3.4*1024*1024) or 2,243,939 seconds or 623 hours or 25 days.
Something tells me this doctor's office is going to have a problem.
Now, let's assume, you can dedupe or compress the data to 50%. Some of the image data cannot be deduped or compressed. Even with that, you are at 12.5 days of downtime. Double the network performance, and the business is still down for almost a week, at 6.25 days, and buying 30 Mbits of sustained download speed is not cheap these days for a small business.
Let's look at this again with 80% dedupe or compression. With 30 Mbits of download speed, it is still over 5 days of downtime. Hence, I am totally and completely confused as to why anyone thinks this is a workable solution for a business.