What spin down time should be used for these drives? Does the drive spin down if it is still shingling?
Backstory: I've set up a new server with 2 of these as data drives and 3rd as the parity drive. I've temporarily mounted my old drives in the same server to transfer all of my files over. The first transfers of 2TB worth of movies went fine with speed averaging 40MB/s but the second transfer of tv data is only getting 10MB/s or worse.
Notes:
I originally started the tv transfer before the movies transfer was finished. I thought it would speed up after the movies transfer finished but it didn't.
My tv data includes .tbn, .nfo, and .jpg files so it's possible these small files were causing issues but I've deleted them all and the transfer is still slow.
The data is being moved from 4 different drives one at a time. The same drives that the movies were on.
Often a transfer completes overnight or while I'm at work so there are hours between the end of one transfer and the start of the next. When I start the next transfer the first 5GB - 25GB or so will be fast but then it slows down again.
I've tried both mv on the command line and midnight commander to move the files.
My current hypothesis is that the default spin down time of 15 minutes is not enough for the drive to finish its shingling activity if it's seriously backed up. If the persistent cache is empty then the first 25GB of writes should be fast, shouldn't they? Is there anything I can do to diagnose this issue further?