qnap check file system volume could not be unmounted

I stopped all activity on the NAS, but that didn't appear to increase the speed. The cache did finally flush completely although it took close to 60 hours. I haven't yet noticed any file corruption and have opened multiple random files.

When I viewed the volume through File Station, it appeared intact, I expected the worse, but must have been lucky. It failed a couple of times but finally completed successfully and the volume mounted.

While the cache was flushing, I performed File Check on the Volume to bring it online. This might be expected if the volume is unmounted due to cache flush? I attempted to run a File Check on it, but it fails. The volume on Raid Group 1, is unmounted. Raid Group 2: disk 8 raid 0 as Storage Pool 2 with two volumes one thick 2.97 tb and one thick 3.47 tb. Raid Group 1 disks 1-7 raid 5 as Storage Pool 1 with one thick volume System has 8 8tb drives, 3 raid groups, 2 pools and 3 volumes Should I wait for the flush to finish, or can I try again without damage? When I go to manage the volume, the only actions available are check file system, and format. I tried to mount the volume by running a file check, but it failed. I know volumes will be unmounted during a file check, not sure while flushing cache. Is it normal for the volume to be unmounted during this process? I have two pools with 3 volumes and the other two volumes are still mounted. Just seems to me it wouldn't take very long to write out the cache. Is that a normal time to flush the cache? I could find no documentation one way or the other. It has been close to 24 hours and only 35% of the Cache has flushed. Unintentionally, I turned off the Cache Acceleration and the system started to flush cache. (card and SSDs are on the compatibility list.) To this, I have added an expansion card and two 1 TB SSDs combined in a Raid 1 to use as cache Read-Write. dev/mapper/cachedev2 /share/CACHEDEV2_DATA ext4 rw,usrjquota=aquota.I have a TS-832X with 8 GB Ram. I have 7 /dev/mapper/cachedev# mount points and problem is with 3 of them. đ1:09:37 Systemđ27.0.0.1 Storage & Snapshots Volume Failed to check file system of volume 'Vol_Qsync'. đ0:48:02 Systemđ27.0.0.1 Storage & Snapshots Volume File system not clean.

I have a problem with unhealthy state of file system :

Qnap check file system volume could not be unmounted