The synocli-disk package provides some disk related tools to advanced Linux users:

• e2fsprogs
  Ext2/3/4 filesystem userspace utilities. [GPL]
• fuse
  The reference implementation of the Linux FUSE (Filesystem in Userspace) interface. [GPLv2, LGPLv2.1 (libfuse.so, libulockmgr.so)]
• TestDisk
  TestDisk is powerful free data recovery software.
• ncdu
  Ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don't have an entire graphical setup available, but it is a useful tool even on regular desktop systems. [MIT]
• davfs2
  Mount a WebDAV resource as a regular file system. [GPLv3]
• lsscsi
  The lsscsi command lists information about SCSI devices in Linux. [GPLv2]
• dar
  DAR is a shell command that backs up from a single file to a whole filesystems, taking care of hard links, Extended Attributes, sparse files, MacOS's file forks, any inode type (including Solaris Door inodes), etc. [GPLv3]
• ddrescue
  GNU ddrescue is a data recovery tool. It copies data from one file or block device (hard disc, cdrom, etc) to another, trying hard to rescue data in case of read errors. [GNU GPL]