I'm using Ubuntu Server 14.04 and have several external storage arrays (nothing special a 5 disk RAID10 box, they appear to the OS as a single disk) I use the UUID to mount them with /etc/fstab because I understand that the OS can assign different /dev/sdx letters to disks upon reboot and I need each one mounted at the same point each boot. Everything mounts fine on boot up but often later (a few days or weeks maybe) the files mounted at the location will "disappear" and not show up until the next reboot. After investigating I've found some inconsistencies, I just do not know what would cause them, below is what I've found.
UUID=24ce55a6-58c6-4f91-a7fd-f602c87dae77 /data-mount ext4 defaults,rw 0 0
blkid -c /dev/null:
/dev/sdc1: UUID="24ce55a6-58c6-4f91-a7fd-f602c87dae77" TYPE="ext4"
/dev/sdb1 7.3T 2.7T 4.3T 39% /data-mount
dir: reading directory .: Input/output error
Sometimes I can run the dir command and get data on the disk...I don't understand why it shows mounted as /dev/sdb1 when using df but blkid shows it as /dev/sdc1. I'm not sure what I have wrong but I have 4 of these RAID10 devices and only one doesn't seem to do this but they are all configured the same way as far as I can tell, I'm just looking for ideas on how to fix this.