On 15-10-27 02:53 PM, Martin Schröder wrote:
And then there are SSDs. PCIE SSDs do up to 3000 MB/s write throughput.
https://www-ssl.intel.com/content/www/us/en/solid-state-drives/solid-state-drives-dc-p3608-series.html
And I'm sure there are tape libraries that can write that, too. :-)
I disregarded that part, based on the unsustainable assumptions elsewhere.
Plus, how much would 2.5PB of PCIe SSD cost?!?!?
As to tape libraries... interesting idea. An LTO-6 drive can write at
~160MBytes/sec, and that's pretty much the top end of
generally-available tape drives today, so you'd still need an 8-drive
RAIT-0 setup. After taking into account library changer latency, I'd
guess you'd need a custom buffering solution, maybe one system to shard
the data, then ~10 systems to buffer the data to ~10 tape drives with a
big enough buffer to sustain the ~2-4min it can take to eject and load a
new tape in a big library. Perhaps that's where the PCIe SSDs come in? :-)
(10Gbits/sec ~= 1 Gbyte/sec ~= 60 Gbytes/min... you could probably get
away with a 256MB SSD)
A 12-drive StorageTek LTO6 library with ~1000 tapes costs around $2M
last I heard, but at least the tape cost is reasonable once you get
going. Of course, you also need the multi-path FC networking gear for
that, and I think OpenBSD just dropped FC support.
An alternative might be a z-series mainframe, I hear they have massive
I/O capabilities. But they don't (AFAIK) run OpenBSD.
-Adam
