LTO Roadmap and Generations
Scope
This domain covers generation history, the doubling plan for capacity and throughput, media chemistry changes, and the refresh planning that follows from them.
Core rules
- Generations run from LTO-1 (2000, 100 GB native) to LTO-9 (2021, 18 TB native, 400 MB/s native). LTO-7 is 6/15 TB, LTO-8 12/30 TB, LTO-9 18/45 TB.
- The published roadmap doubles native capacity each generation: LTO-10 at 36 TB (90 TB compressed), LTO-11 72/180, LTO-12 144/360. The LTO Program (HPE, IBM, Quantum) publishes each generation's specification; ship dates slip, the doubling target has held.
- Media chemistry changed at LTO-8: LTO-7 is metal particle (MP); LTO-8 and LTO-9 use barium ferrite (BaFe). That shift is why LTO-8 needed new heads and why older MP media cannot simply be pushed to higher density.
- LTO-7 Type M (M8) media: MP LTO-7 cartridges initialised by an LTO-8 drive to 9 TB usable. Readable and writable only in LTO-8 drives - not LTO-7, not LTO-9.
- Throughput scales too: 120 MB/s (LTO-4), 160, 300, 360, 400 MB/s native at LTO-9.
Worked example
An archive written on LTO-6 in 2014. Read support reaches back only two generations, so an LTO-8 drive still reads LTO-6, but an LTO-9 drive does not. The moment the site adopts LTO-9, that LTO-6 media is stranded unless it was migrated. Schedule the migration to finish before the two-generations-back window closes.
Traps
- Treating the roadmap as a delivery date and buying capacity plans around it.
- Buying LTO-7 M8 media for a mixed LTO-7/LTO-8 fleet.
- Assuming every later drive reads every older generation.