Large External Hard Drive Mounting Issue on the RT-AC3100

[NivekTheSizable]

Greetings all. I'm running the latest Merlin firmware (384.14_2) on a RT-AC3100. I currently have a WD 4TB hard drive attached on the USB 3.0 port at 3.0 speeds and it works great. However, the disk is nearly full and I would like to replace it with one of two WD hard drives I have already: either the WD Easystore 8TB External USB 3.0 Hard Drive (model WDBCKA0080HBK-NESN) or the 14TB version of that drive (Model WDBCKA0140HBK-NESN).

When I attempt to mount either drive onto either USB port (including both 2.0 and 3.0 speeds on the USB3 port), it fails to mount, with log entries like this:
Jan 3 22:39:40 kernel: usb 1-1: new SuperSpeed USB device using xhci_hcd and address 2
Jan 3 22:39:40 kernel: xhci_hcd 0000:00:0c.0: WARN: short transfer on control ep
Jan 3 22:39:40 kernel: xhci_hcd 0000:00:0c.0: WARN: short transfer on control ep
Jan 3 22:39:40 kernel: xhci_hcd 0000:00:0c.0: WARN: short transfer on control ep
Jan 3 22:39:40 kernel: xhci_hcd 0000:00:0c.0: WARN: short transfer on control ep
Jan 3 22:39:40 kernel: xhci_hcd 0000:00:0c.0: disable burst on ep 2
Jan 3 22:39:40 kernel: xhci_hcd 0000:00:0c.0: WARN no SS endpoint bMaxBurst
Jan 3 22:39:40 kernel: scsi2 : usb-storage 1-1:1.0
Jan 3 22:39:41 kernel: scsi 2:0:0:0: Direct-Access WD easystore 25FB 3004 PQ: 0 ANSI: 6
Jan 3 22:39:41 kernel: sd 2:0:0:0: Attached scsi generic sg0 type 0
Jan 3 22:39:41 kernel: scsi 2:0:0:1: Enclosure WD SES Device 3004 PQ: 0 ANSI: 6
Jan 3 22:39:41 kernel: scsi 2:0:0:1: Attached scsi generic sg1 type 13
Jan 3 22:39:41 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:41 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:41 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:43 kernel: sd 2:0:0:0: [sda] Spinning up disk....
Jan 3 22:39:43 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:43 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:43 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:44 kernel: .
Jan 3 22:39:44 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:44 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:44 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:59 kernel: .ready
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] Very big device. Trying to use READ CAPACITY(16).
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] 15628052480 512-byte logical blocks: (8.00 TB/7.27 TiB)
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] 4096-byte physical blocks
Jan 3 22:39:59 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] Write Protect is off
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] Assuming drive cache: write through
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] Very big device. Trying to use READ CAPACITY(16).
Jan 3 22:39:59 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:39:59 kernel: sd 2:0:0:0: [sda] Assuming drive cache: write through
Jan 3 22:40:00 kernel: sda: sda1
Jan 3 22:40:00 kernel: sd 2:0:0:0: [sda] Very big device. Trying to use READ CAPACITY(16).
Jan 3 22:40:00 kernel: xhci_hcd 0000:00:0c.0: WARN: Stalled endpoint
Jan 3 22:40:00 kernel: sd 2:0:0:0: [sda] Assuming drive cache: write through

The same verbiage for the 14TB model appears in the logs when trying to mount that one. The 8TB drive was formatted in Windows 10 with exFAT and 2048K cluster sizes; the 14TB is exFAT with 4096K clusters.

There are some older threads on here about these kinds of problems (such as https://www.snbforums.com/threads/p...on-rt-ac68u-with-asuswrt-merlin-380-59.33217/) but I was wondering if there was a quick solution. My next troubleshooting attempt will be to reformat one of the drives to NTFS. I'd prefer not to use ext4, if the firmware supports it, but if it's the only option I'll do it.

Any thoughts? These large drives are starting to get pretty common. Thanks.

 

[ColinTaylor]

The router doesn't support exFAT.

 

[Sanna1967]

https://event.asus.com/2009/networks/disksupport/

here the compatible HDD size and format with asus routers

 

[NivekTheSizable]

Thank you each for your replies. I am happy to report that reformatting the drives as NTFS allows both to be recognized and at USB 3.0 speeds. Fortunately, that ASUS page seems out of date for the drive size maximums.