=====================================================================fsarchiver: Filesystem Archiver for Linux [http://www.fsarchiver.org]=====================================================================About FSArchiver----------------FSArchiver is a system tool that allows you to save the contents of afilesystem to a compressed archive file. The filesystem contents can berestored on a device which has a different size and it can be restored on adifferent filesystem. Unlike tar/dar, FSArchiver also creates thefilesystem when it extracts the data to devices. Everything is checksummedin the archive in order to protect the data. If the archive is corrupt, youjust lose the current file, not the whole archive. FSArchiver is releasedunder the GPLv2 license. You should read the Quick Start guide[http://www.fsarchiver.org/quickstart/] if you are using FSArchiver for thefirst time.Detailed description--------------------The purpose of this project is to provide a safe and flexible filesystembackup/deployment tool. Other open-source filesystems tools such asPartimage already exist. These tools are working at the filesystem blocklevel, so it's not possible to restore the backup to a smaller device, andrestoring to a bigger one forces you to resize the filesystem by hand.The purpose is to have a very flexible program. FSArchiver can extract anarchive to a device which is smaller that the original one as long as thereis enough space to store the data. It can also restore the data on adifferent filesystem, so you can use it when you want to convert yourfilesystem: you can backup an EXT3 filesystem, and restore it as ReiserFS.FSArchiver works at the file level. It can make an archive of most Linuxfilesystems (EXT3, ReiserFS, XFS, ...) that the running kernel can mountwith read-write support. It will preserve all the standard Unix fileattributes (permissions, timestamps, symbolic-links, hard-links,extended-attributes, ...), as long as the kernel has support for themenabled.Limitations-----------There are limitations anyway: FAT filesystem is supported basically for EFISystem Partition volumes (UEFI systems) and won't work for bootable Windowsvolumes. Also, NTFS support is experimental and shouldn't be used inproduction. FSArchiver won't preserve features which are very specific to afilesystem. For instance, if you create a snapshot in a Btrfs volume,FSArchiver won't know anything about that, and it will just backup thecontents seen when you mount the device.FSArchiver is safe when it makes backups of devices which are not mountedor are mounted read-only. There is an option to force the backup of aread-write mounted volume, but there may be problems with the files thatchanged during the backup. If you want to backup a device which are in use,the best thing to do is to make an LVM snapshot of it using lvcreate -s,which is part of the LVM userland tools. Unfortunately you can only makesnapshots of devices which are LVM Logical Volumes.Protection against data loss----------------------------FSArchiver is using two levels of checksums to protect your data againstcorruption. Each block of each file has a 32-bit checksum written in thearchive. That way we can identify which block of your file is damaged. Oncea file has been restored, the MD5 checksum of the whole file is compared tothe original MD5. It's a 128-bit checksum, so it will detect all filecorruptions. In case one file is damaged, FSArchiver will restore all theother files from your archive, so you won't lose all your data. It's verydifferent from tar.gz where the whole tar is compressed with gzip. In thatcase, the data which are written after the corruption are lost.FSArchiver-0.2.3 and newer versions are able to ignore corrupt contents inan archive file, so all the other files will be restored.