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.
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.
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.