Remount a QNAP NAS RAID volume

Following a file system check, where a RAID volume is not remounted automatically after a reboot is it necessary to run the file system check multiple times?

A message may appear in the event log ‘file system not clean’ or ‘system not shut down correctly’. This often follows a power outage or surge, and it is not uncommon for one or more of the RAID volumes not to mount.

Where a NAS gets shut down unexpectedly, it should automatically complete a file system check. However if this doesn’t work it will be necessary to run a diagnostic assessment. The QNAP NAS boxes run a custom Linux setup based on Ubuntu.

Firstly run mdadm to assess the status of the RAID. This will indicate the following:


  • Version
  • Creation Time
  • Raid Level
  • Array Siz
  • Used Dev Size
  • Raid Devices
  • Total Devices
  • Preferred Minor
  • Persistence
  • Update Time
  • State
  • Active Devices
  • Working Devices
  • Failed Devices
  • Spare Devices
  • Layout
  • Chunk Size

Secondly check the filesystem for errors # e2fsck_64 -fp /dev/md0. Assuming the volumes still exist using the df -h command, run a manual file system check and repair. This may take a long time and it’s important not to rush the process. Once completed attempt to remount the device # mount -t ext4 /dev/md1 /share/MD1_DATA. If this fails, a RAID reconstruction is the next option.

Further reading

Drobo and BeyondRAID data recovery

Data backup versus RAID storage

VMware data recovery