NAS (any brand) external USB drive bay - issues.
In my case, Synology DS212.
I just bought a $45 nice steel box 2 drive bay box. Has USB3 connector.
The chip inside is a Prolific USB3 to SATA bridge. It has these switch-selected modes:
Set for RAID0 (box's role is backup the NAS excluding big image backups of PCs).
Plug the external box into DS212's USB2 port. Comes up as a 3.8TB drive. Perfect.
Move the plug to the USB3 port on the DS212. wait, wait. Nothing recognized.
I thought the bridge chip in the box made it transparent to the host (NAS) as to which of the above four settings was in use. NAS would not be RAID-aware for this box.
I filed a ticket with Synology and explained as above: works on USB2, not on USB3.
Response was a mistaken "Synology DSM (OS) does not support RAID on external drives).
I countered with: Works on USB2. Not USB3. Box makes it transparent to the NAS.
So I use USB2 and it works just fine. At 20Mbytes/sec. Drives are formatted ext4 by NAS OS (DSM), with switches set to RAID0. NAS sees 3.8TB. On USB2 only.
It also doesn't work with a one-drive enclosure, USB3 and some or all USB3 hubs. Drive enclosure works fine USB3 if a hub is not introduced.
Any ideas? I think the USB3 hardware in the circa 2012 NAS is at fault. Probably using 2011 or older USB3 chips. Hardware or Linux USB3 drivers at fault? Both? Any other 4 year old USB3 NAS work correctly with an external USB3 hub?
In my case, Synology DS212.
I just bought a $45 nice steel box 2 drive bay box. Has USB3 connector.
The chip inside is a Prolific USB3 to SATA bridge. It has these switch-selected modes:
- NORMAL - just a USB hub so the host sees 2 drives
- JBOD - host sees one drive (volume?), size is sum of two drives
- RAID0 (striped) - host sees one drive, size is sum of two drives
- RAID1 (mirrored) - host sees one drive, size is smaller of two drives
Set for RAID0 (box's role is backup the NAS excluding big image backups of PCs).
Plug the external box into DS212's USB2 port. Comes up as a 3.8TB drive. Perfect.
Move the plug to the USB3 port on the DS212. wait, wait. Nothing recognized.
I thought the bridge chip in the box made it transparent to the host (NAS) as to which of the above four settings was in use. NAS would not be RAID-aware for this box.
I filed a ticket with Synology and explained as above: works on USB2, not on USB3.
Response was a mistaken "Synology DSM (OS) does not support RAID on external drives).
I countered with: Works on USB2. Not USB3. Box makes it transparent to the NAS.
So I use USB2 and it works just fine. At 20Mbytes/sec. Drives are formatted ext4 by NAS OS (DSM), with switches set to RAID0. NAS sees 3.8TB. On USB2 only.
It also doesn't work with a one-drive enclosure, USB3 and some or all USB3 hubs. Drive enclosure works fine USB3 if a hub is not introduced.
Any ideas? I think the USB3 hardware in the circa 2012 NAS is at fault. Probably using 2011 or older USB3 chips. Hardware or Linux USB3 drivers at fault? Both? Any other 4 year old USB3 NAS work correctly with an external USB3 hub?