problem med extern hårddisk

Hej!

Idag har det hänt två gånger. Min externa USB-disk "ballar ur". Det är
en 2,5" disk ansluten via USB2 till en ODROID XU4 (ARM) med Debian 8.

Linux odroid 3.10.82+ #1 SMP PREEMPT Fri Oct 16 03:58:03 MDT 2015
armv7l GNU/Linux

Det som händer är att disken blir skrivskyddad.

dmesg ger följande:
[ 9962.787626] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9963.288536] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9963.788978] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9964.289258] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9964.790003] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9965.290524] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9965.791048] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9966.293220] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9966.791879] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9967.292918] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9967.793436] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9968.293865] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9968.794616] [c0] sd 0:0:0:0: rejecting I/O to offline device
[ 9968.890520] [c5] systemd-journald[254]: /dev/kmsg buffer overrun,
some messages lost. [ 9969.564994] [c7] sd 0:0:0:0: [sda] Synchronizing
SCSI cache [ 9969.571042] [c4] sd 0:0:0:0: [sda]  
[ 9969.573223] Result: hostbyte=0x01 driverbyte=0x00
[ 9969.686654] [c4] usb 1-1: new high-speed USB device number 3 using
s5p-ehci [ 9973.926865] [c3] Aborting journal on device sda1-8.
[ 9973.930556] [c3] Buffer I/O error on device sda1, logical block
30441472 [ 9973.936965] [c3] lost page write due to I/O error on sda1
[ 9973.942540] [c3] JBD2: Error -5 detected when updating journal
superblock for sda1-8. [ 9974.831871] [c0] usb 1-1: can't set config
#1, error -110 [10038.190714] [c6] EXT4-fs warning (device sda1):
__ext4_read_dirblock:681: error reading directory block (ino 2359386,
block 0) [10130.501449] [c0] EXT4-fs warning (device sda1):
__ext4_read_dirblock:681: error reading directory block (ino 2359386,
block 0) [10130.511709] [c0] EXT4-fs warning (device sda1):
__ext4_read_dirblock:681: error reading directory block (ino 2359386,
block 0) [10130.525231] [c0] EXT4-fs warning (device sda1):
__ext4_read_dirblock:681: error reading directory block (ino 2359386,
block 0) [10130.535316] [c0] EXT4-fs warning (device sda1):
__ext4_read_dirblock:681: error reading directory block (ino 2359386,
block 0) [10459.835036] [c4] EXT4-fs warning (device sda1):
__ext4_read_dirblock:681: error reading directory block (ino 2359386,
block 0) [10459.845479] [c4] EXT4-fs error (device sda1):
__ext4_journal_start_sb:62: Detected aborted journal [10459.853881]
[c4] EXT4-fs (sda1): Remounting filesystem read-only
jan@odroid:/sda1/data$ 

Vad ska man gissa att problemet är? Disken? Datorn? Bugg?

/Janne