R1Soft Hot copy

R1Soft Hot Copy

Stable release	3.6.0 Stable[1] / April 8, 2010; 21 months ago (2010-04-08)[1]
Development status	Active
Written in	C
Operating system	Linux with Linux kernel version 2.6[2]
Platform	Linux running on x86 and x86-64 machines.
Available in	English
Type	Disk snapshot (computer storage) software
License	Freeware
Website	R1soft Hot Copy Home

R1Soft Hot Copy (hcp) is an online disk snapshot application for Linux computers, produced by R1Soft. Hot Copy creates point-in-time snapshots of a disk while it is running.^[3] It is similar to the snapshot feature of Linux LVM2.

Contents 1 Features 2 Implementation 3 Compared to Logical Volume Manager Snapshots 4 Limitations 5 See also 6 References 7 External links

Features

R1Soft Hot Copy can:^[1]

• Create online disk snapshots while a Linux computer is running.
• Take snapshots so that the computer's file system is in a consistent state.
• Use a copy-on-write snapshot method to efficiently grow snapshot storage as changes are made.
• Create writable and read-only snapshots.
• Work without dedicated snapshot storage using unused portions of the computers disk to store changed disk blocks.
• Can create multiple snapshot versions of each block device

Implementation

R1Soft Hot Copy is implemented as Linux block device driver and is distributed as a loadable kernel module and command line utility (hcp). Hot Copy filters reads and writes to the real disk and performs a copy-on-write when changes are made to the disk. Unused areas of the hard disk are used to store changed blocks in order to maintain a point-in-time snapshot.

Compared to Logical Volume Manager Snapshots

R1Soft Hot Copy has several differences when compared to Logical Volume Manager snapshots:^[4]

• In order to use LVM the computer's file system must be located on an LVM Volume Group. Many Linux computers do not use LVM. Hot Copy can work with any Linux block device.
• LVM requires dedicated physical snapshot storage for changed blocks.^[5] This requires that the server administrator configure LVM when the system is set up in a way that reserves special storage for LVM snapshots.
• LVM is licensed under an Open source license.

Limitations

• R1Soft Hot Copy does not support 2.4 Linux kernels, only 2.6 are supported.^[2]

See also

• Logical Volume Manager (Linux)
• Snapshot (computer storage)
• Btrfs - A file system with similar feature

References

External links

• R1Soft Hot Copy
• R1Soft Hot Copy Documentation