Maybe a real life example of mass storage by people that has been around for ages and actually was designed initially to be a relatively decentralised system.
It was designed for universities, organisations and others to run a server holding the information and no one server had control. It also was designed to store all the information on each of the servers. Obviously designed very early on and SAFE is using a different system. its called NNTP (Network News Transfer Protocol)
Today it sees a small number of very large servers to hold all the binary data, which it was not originally designed to do. It is still heavily used and holds all the files that are being torrent with some servers retaining the files for many years. They do respect take down notices which is why they survive the copyright trolls.
All those files are currently amounting to 5-7TB per day of storage and each of the companies are adding storage to keep up, and some never deleting anymore (except take down notices). Oh and the 5-7TB per day includes all those spamming/scamming or trying to take down the servers by over loading them, or use up their storage faster than they can add it. AND too boot files can be added to NNTP at no cost other than a internet connection and at most is a few dollars a month.
Now we expect that the number of people and the size of their vaults will by far exceed that which any one company can. So if we take a proportion of SAFE users to world wide internet users we would expect that SAFEâs storage requirements will be far less early on. People will be adding 1TB vaults and if 1% of internet users use SAFE and 1/10 add drives then that is over 1 million vaults averaging (when needed) 1TB. Safe will dwarf NNTP and that is while SAFE is small compared to the available audience of NNTP.
SAFE would only need 10 1TB vaults added per day to exceed NNTP and maybe even all the âdropboxesâ as well. Remember that (exact) duplication will not exist so all those duplicate copies of vids etc will only take the space needed for one copy. That is something NNTP and âdropboxesâ do not (widely) currently do.
Now as to âstagnantâ data, David has said that it will âgravitateâ to archive nodes. These nodes are ones that either are set up by MAIDSAFE or shown that they remain on-line almost permanently and code (datachains?) can be used to validate them when they come back on line, so reducing the churning of their data stored. As long as 4 copies exist then no data copying is needed when one goes off line. In other words if there were data in only 4 nodes and one archive node went off line than that data would be copied. Then the node came back online so there is now 5 copies. If another archive node that happened to have a copy of that data went offline then no copying of that data is needed since 4 copies still exist.
tl;dr
eventually stagnant data will exist in more than 4 archive nodes and the occasional downtime of an archive node will not cause significant copying of data in the network due to previous occurrences of the downtime causing its data to exist in more than 4 (archive) nodes eventually.
One would expect there to be many such archive nodes and as tech improves the number increase.
Also storage space technology is still progressing very fast and as fast as we can fill up drives.
When I was a young engineer we used 128Kbyte floppys disks and fllled them up quickly, then 360KB, 720KB, 1.44MB etc. They were all filled quickly by the average user. Then 5, 10, 20, 60, 200MB drives which also were filled by the average user, but took a lot longer to do so.
Then when we got to GB range of drives very often it took the life of the computer to fill the drive. So while data uses was increasing the drives were increasing faster than the average user could use them. One reason being that CD drives held a lot of the duplicate data, a lot of data increase was research data and corporate data, not he ordinary user/worker.
Now that we have TB drives, I find it rare to see any average home user even using 1/2 their drive for the whole life of the computer. In other words there has been both a increase in de-duplication because of the internet and DVDs/etc and the rate of drive size increase is still exceeding the data storage requirement increases.
This is good news for SAFE since farming storage can exceed user requirements without any excessive addition of storage space by users, but by users allocating 1/2 of their 2TB drives to a vault.