![Qnap check filesystem](https://kumkoniak.com/39.jpg)
![qnap check filesystem qnap check filesystem](https://www.qnap.com/images/products/Application/notes/Qes_VMware_backups_10.png)
You should be able to continue the “Check File System” via the GUI. Afterwards use the list command to check if all the effect volumes are off the list. To force the unmount you have to use the lazy unmount option ‘-l’. Now to unmount the main volume, though you most likely encounter the “device is busy” when using the same command line. Umount /share/CE_CACHEDEV1_DATA/.samba/lock/msg.lock Umount /share/CE_CACHEDEV1_DATA/.qpkg/container-station/kernel-module Unmount any folders within “/share/CE_CACHEDEV1_DATA” Look at the list and ignore any volumes that isn’t effected by this issue To fix this we have to use Telnet or SSH into the QNAP, and forcefully unmount the volumes. No matter how many times you do this check, the system will complain about not being able to unmount the disk. But then I’ve encounter this error when doing the ‘Check File System’, “ Examination failed (Cannot unmount disk)” half way through the check. Since my SSD was in ‘Read Only’ mode I’ve decided to disable the ‘Cache Acceleration’ by using the “Remove SSD Cache Volume” option. This is QNAP safety procedures even if you are using ‘Read Only’ Cache acceleration it will lock down the volumes. The result was any linked volume will become ‘Read Only’ state, you must do a ‘Check File System’ to enable the Storage Pool. I don't need anything complicated like checksums, all I want to know if the NAS contains all the files in the btrfs-filesystem.I did something foolish today, I’ve accidentally removed one of the SSD that was used for Cache Acceleration. I am therefore looking for for a program or a script which can help me to check is rsync is running correctly.
![qnap check filesystem qnap check filesystem](http://qnapsupport.net/wp-content/uploads/2016/08/Qnap-file-system-check-unmount-volume-4.jpg)
![qnap check filesystem qnap check filesystem](https://support.qnap.ru/hc/article_attachments/360000827173/03.png)
So it seems that in my situation rsync is not entirely trustworthy but I would like to compare the two directory trees to see if there are any files missing on the NAS and/or if there are files which dont exists on the btrfs anymore and which should have been deleted by rsync according.
![qnap check filesystem qnap check filesystem](http://smallbusinessfasr270.weebly.com/uploads/1/2/4/2/124249862/470302887.jpg)
It is most likely not a rights issue since rsync is run as root. Now by pure chance I found out that some directories were not synchronized correctly - the directories existed on the NAS but they were empty. I call rsync with one -v and send the results of the run to my email account to be sure everything is synchronized correctly. The path is then mounted on the machine with the btrfs-bilesystem and rsync is called to keep the nfs export synced to the main filesystem. My backup consists of a NAS which exports one path via NFS. I have a btrfs-filesystem consisting of several harddrives in which is stored about 11 TB of Data.
![Qnap check filesystem](https://kumkoniak.com/39.jpg)