Details have emerged from yesterday's webcast of Oracle's tape roadmap showing three format and SL8500 library, reaching a 20TB cartridge and 2 exabyte library in 2015.
As we thought it is a three-generation job, starting off from the current T10k-B tape format with 1TB raw capacity and a 120MB/sec throughput. The current StreamLine 8500 (SL8500) library has a 100PB capacity and a 276TB/hour bandwidth.
Oracle sees a generation 3 tape - the T10k-B being the generation 2 tape and the T10k-A the generation one - so let's call it the T10k-C, with 3 - 5TB capacity and 180 - 270MB/sec throughput. We don't know if these numbers are ranges with the product fitting in there somewhere, or the upper and lower bounds of versions of the T10k-B. We're going to assume a range until Oracle tells us different.
The SL8500 at this point will have a 300-500PB capacity and a 441-621TB/hr throughput. Looking at the relationship between tape capacity and library capacity we see the latter is 100,000 times the former in both cases indicating that the library's slot count has not changed.
If we divide the 2010 SL8500's throughput of 276TB/hr by the T10k-B drive's throughput of 120MB/sec (276/120) we get a ratio of 2.3. Doing the same math for the 2011 SL8500, meaning 424/180, we get the same ratio of 2.3, indicating that the number of drives in the SL8500 hasn't changed.
If we do that division with the higher throughput numbers, meaning 621/270, we still get the same ratio. It appears that the SL8500 is getting its increase in capacity and throughput purely from faster drives and higher capacity tape, not from a greater number of slots and drives.
In 2013 we have a fourth generation tape, a T10k-D we'll say, with 6-10TB capacity and 270-400MB/sec throughput. The SL8500 now has 600-1000PB capacity and 621-920TB/hr throughput. Once again the slot count stays constant and so does the number of drives, using the same math as before.
The gen 5 tape, a T10k-E, appears in 2015 with a 12-20TB capacity and 400-600MB/sec throughput. At this point the SL8500 has a 1.2EB (1,200PB)-2EB (2,000PB) capacity and a 920-1380TB/hr throughput, the slot and drive count remaining constant again.
It seems odd that in five years Oracle does not intend refreshing the SL8500 library with a higher slot and drive count. By 2015 it will be a quite dated design.
Oracle's EVP for storage and servers, John Fowler, used the 20TB capacity in summary slides in his presentation. If the 12-20TB capacity is a range then a 12TB actual product will under-deliver on the 20TB upper bound by a considerable margin. It looks as if Oracle is running the risk of over-promising and under-delivering.
This roadmap should reassure StorageTek tape users that Oracle intends to be an active steward of their interests and does not want to see them desert and join the ranks of IBM or SpectraLogic library users. ®