Hello, I am wondering if this drive is failing. I ran a GSmartControl - extended test and no errors were detected that way. Noticing here on this machine with some of the journalctl -xb output shown in the following lines: Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=524288, sector=32768, nr_sectors = 8 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32768, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 0, async page read Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32769, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 1, async page read Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32770, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 2, async page read Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32771, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 3, async page read Feb 02 17:10:09 paul-Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32772, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 4, async page read Feb 02 17:10:09 paul-Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32773, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 5, async page read Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32774, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 6, async page read Feb 02 17:10:09 paul-Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32775, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 7, async page read Feb 02 17:10:09 Thinkcentre-M57p kernel: fdisk: attempt to access beyond end of device sdb: rw=0, sector=32768, nr_sectors = 1 limit=0 Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 0, async page read Feb 02 17:10:09 Thinkcentre-M57p kernel: Buffer I/O error on dev dm-3, logical block 1, async page read There is no /dev/sdb device showing up in fdisk -l or lsblk -fs right now though so could it be an iteration of the past when possibly my (usb filing drive) was connected to the machine? Also I would like to ask you about all this information about COW and Btrfs. What's going on here with 'defragmenting' and 'scrubbing' in a generalized sense? What is a sign of the need for it? I've been experiencing a minor freeze for about 45 seconds to a minute after a powercycle and login but then things seem to clear up.