On 13/11/2021 16:52, Rich Freeman wrote:
On Sat, Nov 13, 2021 at 12:35 AM William Kenworthy <bi...@iinet.net.au> wrote:
Look at the odroid HC4 - I am using 5x the older HC2 version for moosefs
- they are USB3 based but work well in this application. They are arm32
but 64bit is not needed.
I like the idea behind the HC series Odroids, but being limited to 1-2
drives per node seems a bit contraining. With the USB3 approach there
really is no limit to how many drives I can put on a node, as long as
I don't mind the performance drop. I'm more concerned with static
storage capacity in this case. If you're using 1Gbps ethernet then I
guess two drives is already going to saturate the network if they're
able to read sequentially.
Note that the md-raid advice is "do NOT use USB. We don't understand
why, but bad things seem to happen". Even when explicitly designed for
it, multiplexing drives on a single comms channel isn't always a good
idea...
Years ago I built a CD copy station. Can't remember the exact layout,
but it was something like three CD-writers and a hard drive on PATA-0
and PATA-1. I think the CD-writers achieved something like 0.5x speeds!
So we bought two add-in cards, with the hd and first CD-writer were on
PATA-0, and one CD-writer each on PATA-1, PATA-2 and PATA-3. They FLEW!
They were something like 32x drives and really achieved a full write in
about 2 minutes!
Cheers,
Wol
