Remove the 'noauto' value from the /store mount point entry in /etc/fstab before you remove HA.
If the file system is XFS, the mount point entry should have the following text:
UUID=uuid /store xfs inode64,logbsize=256k,noatime,nobarrier 0 0
If the file system is ext4, the mount point entry should have the following text:
UUID=uuid /store ext4 noatime,nobarrier 0 0
Save and close the file.
When you remove an HA host from a cluster, the host restarts.