DiskScan scans the entire surface of a disk, alerts when a sector is unreadable, and uses the read timing to warn when a sector is having problems. It will tell when a disk has failed and already has bad sectors and also when the disk is near failure and takes too long to read the data.
sdb is a really simple program to benchmark disks. It only writes/reads data sequentially to/from a file and calculates the performance of this action. A memory buffer is used for input/output to get values close to the real performance of the disk or RAID system. You can use flags like O_DIRECT and O_SYNC to avoid buffering by the operating system. It is similar to dd, but there are some differences, since dd was not created for benchmarking a disk. It is possible to initialize the buffer with random values before writing them to the disk or a file on the disk. It is a simple but effective program to get the maximum speed of a disk. Due to the simplicity, you will get the results much faster than with a more complex benchmark.
The Exquisite `df' (xdf) is a souped-up version of df(1) rewritten from scratch and focused on flexibility of field selection and output format. It offers HTML and CSV outputs, besides the traditional text-based console output. It is fit for system administrators who are tired of post-processing df(1) output through shell or Perl scripts in order to avoid broken lines or to get a simple total/summary line.
NouvaLinux backup and rescue is a live CD with some special tools for making backups and system recovery. The main tool is an application made by RyXéo (a free software company): a partclone GUI. Backup is Clonezilla compatible: you can make backups with NouvaLinux backup and restore them with Clonezilla.
Gpart is a small tool which tries to guess which partitions are on a PC harddisk in case the primary partition table was damaged. It works by scanning through the device (or file) given on the commandline on a sector basis. Each guessing module is asked if it thinks a filesystem it knows about could start at a given sector. Several filesystem guessing modules are built in, and others can be added dynamically.
Linfo displays system statistics such as disk space usage, network usage, hardware information, mounted file systems, hard drives, RAM, hostname, uptime, etc. The Linux version works by parsing the /proc and /sys filesystems and also by connecting to daemons such as hddtemp for determining physical health.