I recently upgraded from OMV 2 to OMV 4. Upgrade went fine, and I migrated from a RAID setup to Union Filesystem (all data backed up to external drives). Since the upgrade, every now and then, I lose connectivity to the filesystem/folders (can't access from media players, or networked PC). I've seen this happen when watching media once ... the movie slowed down and then froze, but most often than not the issue occurs at random times, and at different intervals (sometimes it can be a few days, other times it happens on successive days).
When this occurs I seem to still be able to access the GUI, and there's no obvious spiking of RAM or CPU reported, but trying to access disk details in the GUI grinds to a halt. My media server (HP n40l, with 6 x 4TB HDD) has one disk with a reported SMART error (22 reallocated sectors), which needs to be swapped out and replaced. I've had multiple disk failures over the years, and have never experienced the issue I've described.
From personal experience, does anyone have any suggestions on what the issue could be? I had no problems when running OMV 2 (but I also wasn't using Union FS then, either). Which logs would I need to provide in order to analyse the situation further, and could I please get some guidance on how to extract the relevant logs.
Thanks in advance for any and all support!