I have an SSD connected to my Raspberry Pi 3B+ using the Element14 Pi Desktop kit. The drive is recognized as `/dev/sda` in Raspbian Buster and correctly mounted from `/etc/fstab` at boot, but then will disappear after running for a while.
I started to suspect insufficient power (despite Element14's assertion that a 2.5A power supply was sufficient to power the rpi+SSD), so I bought a new power supply that provided up to 3.5A (I have yet to confirm that with my Kill-a-Watt). I rebooted the pi and and drive mounted correctly as usual, but after about 10 hours, `dmesg` showed:
```
[Fri Apr 17 18:45:11 2020] usb 1-1.3: reset high-speed USB device number 5 using dwc_otg
[Fri Apr 17 18:45:11 2020] sd 0:0:0:0: [sda] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x03 driverbyte=0x00
[Fri Apr 17 18:45:11 2020] sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 0c e0 00 00 00 f0 00
[Fri Apr 17 18:45:11 2020] print_req_error: I/O error, dev sda, sector 843776
[Fri Apr 17 18:45:42 2020] sd 0:0:0:0: [sda] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x03 driverbyte=0x00
[Fri Apr 17 18:45:42 2020] sd 0:0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 0c e0 f0 00 00 10 00
[Fri Apr 17 18:45:42 2020] print_req_error: I/O error, dev sda, sector 844016
[Fri Apr 17 18:45:42 2020] usb 1-1.3: USB disconnect, device number 5
[Fri Apr 17 18:45:42 2020] print_req_error: I/O error, dev sda, sector 105121792
[Fri Apr 17 18:45:42 2020] Buffer I/O error on dev sda1, logical block 13139968, lost sync page write
[Fri Apr 17 18:45:42 2020] print_req_error: I/O error, dev sda, sector 843776
[Fri Apr 17 18:45:42 2020] JBD2: Error -5 detected when updating journal superblock for sda1-8.
[Fri Apr 17 18:45:42 2020] Aborting journal on device sda1-8.
[Fri Apr 17 18:45:42 2020] print_req_error: I/O error, dev sda, sector 105121792
[Fri Apr 17 18:45:42 2020] Buffer I/O error on dev sda1, logical block 13139968, lost sync page write
[Fri Apr 17 18:45:42 2020] JBD2: Error -5 detected when updating journal superblock for sda1-8.
[Fri Apr 17 18:45:42 2020] print_req_error: I/O error, dev sda, sector 50333960
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572963: block 6291494: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572961: block 6291494: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda2): ext4_find_entry:1455: inode #131073: comm bash: reading directory lblock 0
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572956: block 6291493: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572967: block 6291494: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda2): ext4_find_entry:1455: inode #131073: comm bash: reading directory lblock 0
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572960: block 6291493: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda2): ext4_find_entry:1455: inode #131073: comm bash: reading directory lblock 0
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572955: block 6291493: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda2): ext4_find_entry:1455: inode #131073: comm bash: reading directory lblock 0
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572951: block 6291493: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572950: block 6291493: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda2): ext4_find_entry:1455: inode #131073: comm bash: reading directory lblock 0
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572965: block 6291494: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] EXT4-fs error (device sda1): __ext4_get_inode_loc:4708: inode #1572952: block 6291493: comm ldconfig: unable to read itable block
[Fri Apr 17 18:45:42 2020] Buffer I/O error on dev sda2, logical block 15761408, lost sync page write
[Fri Apr 17 18:45:42 2020] JBD2: Error -5 detected when updating journal superblock for sda2-8.
[Fri Apr 17 18:45:42 2020] Aborting journal on device sda2-8.
[Fri Apr 17 18:45:42 2020] Buffer I/O error on dev sda2, logical block 15761408, lost sync page write
[Fri Apr 17 18:45:42 2020] JBD2: Error -5 detected when updating journal superblock for sda2-8.
```
After this, the drive no longer even appears in `lsblk`. It looks as though something is resetting, but I don't know enough about it to dig in much further. What is causing the drive to disappear?
-----
Update:
It looks like this might be a kernel bug, but I haven't figured out what to try next. I'm hesitant to muck with kernel settings that I don't understand.
https://unix.stackexchange.com/questions/239782/connection-problem-with-usb3-external-storage-on-linux-uas-driver-proble…
