Partimage is opensource disk backup software. It saves partitions having a supported filesystem on a sector basis to an image file. Although it runs under Linux, Windows and most Linux filesystems are supported. The image file can be compressed to save disk space and transfer time and can be split into multiple files to be copied to CDs or DVDs.
Partitions can be saved across the network using the partimage network support, or using Samba / NFS (Network File Systems). This provides the ability to perform an hard disk partition recovery after a disk crash.
Clonezilla is a partition and disk imaging/cloning program similar to True Image® or Norton Ghost®. It helps you to do system deployment, bare metal backup and recovery. Two types of Clonezilla are available, Clonezilla live and Clonezilla SE (server edition). Clonezilla live is suitable for single machine backup and restore. While Clonezilla SE is for massive deployment, it can clone many (40 plus!) computers simultaneously. Clonezilla saves and restores only used blocks in the hard disk. This increases the clone efficiency. With some high-end hardware in a 42-node cluster, a multicast restoring at rate 8 GB/min was reported.
Dstat is a versatile replacement for vmstat, iostat, netstat and ifstat. Dstat overcomes some of their limitations and adds some extra features, more counters and flexibility. Dstat is handy for monitoring systems during performance tuning tests, benchmarks or troubleshooting.
Dstat allows you to view all of your system resources in real-time, you can eg. compare disk utilization in combination with interrupts from your IDE controller, or compare the network bandwidth numbers directly with the disk throughput (in the same interval).
Linux has always been able to show how much I/O was going on (the bi and bo columns of the vmstat 1 command). Iotop is a Python program with a top like UI used to show of behalf of which process is the I/O going on.