Filesystems: Difference between revisions
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This page serves to give some information on possible filesystems for Linux machines, in particular those that may be used for very large filesystems (many TB). | This page serves to give some information on possible filesystems for Linux machines, in particular those that may be used for very large filesystems (many TB). The list is sorted by age! | ||
== Ext3 == | == Ext3 == | ||
| Line 6: | Line 6: | ||
* does not support transparent compression | * does not support transparent compression | ||
* does not support checksumming (a data-integrity feature) | * does not support checksumming (a data-integrity feature) | ||
== XFS == | == XFS == | ||
| Line 20: | Line 14: | ||
== ZFS == | == ZFS == | ||
* Sun's filesystem which is natively available on Solaris and OpenSolaris (both of which are freely available) | * Sun's filesystem which is natively available on Solaris and OpenSolaris (both of which are freely available) | ||
* (optional) transparent (gzip) compression (LZO compression available as patch) | |||
* atomic updates - means that the on-disk state is consistent at all times, there's no need to perform a lengthy filesystem check after forced reboots/power failures | |||
* background checksumming and self-healing for data integrity | |||
* Built-in stripes (RAID-0), mirrors (RAID-1) and RAID-Z (it's like software RAID-5, but more efficient due to ZFS's copy-on-write transactional model) | |||
* there are ports of ZFS to FreeBSD and Mac OSX | * there are ports of ZFS to FreeBSD and Mac OSX | ||
* the source code license of ZFS is incompatible with the GPL of the Linux kernel; | * the source code license of ZFS is incompatible with the GPL of the Linux kernel, therefore only available as userland filesystem (ZFS-over-FUSE; see see http://www.wizy.org/wiki/ZFS_on_FUSE) on Linux | ||
* | * installable ZFS/FUSE packages are available e.g. on latest Ubuntu und Fedora (see http://www.linux-magazine.com/w3/issue/103/ZFS.pdf) | ||
== Ext4 == | |||
* fairly new in Linux kernel (since 2.6.27 or so); ext4 is based on ext3 (same developers) | |||
* becoming the default of new versions of Linux distros (Fedora, Ubuntu, ...) | |||
* no 16 GB limitation | |||
* no compression and checksumming (data-integrity) features | |||
== btrfs == | == btrfs == | ||
* latest addition to native Linux filesystems; stable | * latest addition to native Linux filesystems; considered stable since 2.6.31 kernel (http://www.h-online.com/open/Kernel-Log-2-6-31-Tracking--/features/113671) | ||
* (optional) transparent compression | |||
* checksumming for data integrity is implemented | |||
* a review of btrfs from an ex-ZFS engineer: http://lwn.net/Articles/342892/ | * a review of btrfs from an ex-ZFS engineer: http://lwn.net/Articles/342892/ | ||
* you can upgrade an existing linux file system to btrfs without destroying the existing fs or duplicating the data: http://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3 | * you can upgrade an existing linux file system to btrfs without destroying the existing fs or duplicating the data: http://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3 | ||
* http://www.h-online.com/open/The-Btrfs-file-system--/features/113738 | * http://www.h-online.com/open/The-Btrfs-file-system--/features/113738 | ||
Revision as of 16:25, 24 September 2009
This page serves to give some information on possible filesystems for Linux machines, in particular those that may be used for very large filesystems (many TB). The list is sorted by age!
Ext3
- fairly old, but well established and well behaved
- does not support more than 16GB
- does not support transparent compression
- does not support checksumming (a data-integrity feature)
XFS
- SGI's filesystem that was ported to Linux some years ago
- no 16 GB limitation
- no compression and checksumming (data-integrity) features
ZFS
- Sun's filesystem which is natively available on Solaris and OpenSolaris (both of which are freely available)
- (optional) transparent (gzip) compression (LZO compression available as patch)
- atomic updates - means that the on-disk state is consistent at all times, there's no need to perform a lengthy filesystem check after forced reboots/power failures
- background checksumming and self-healing for data integrity
- Built-in stripes (RAID-0), mirrors (RAID-1) and RAID-Z (it's like software RAID-5, but more efficient due to ZFS's copy-on-write transactional model)
- there are ports of ZFS to FreeBSD and Mac OSX
- the source code license of ZFS is incompatible with the GPL of the Linux kernel, therefore only available as userland filesystem (ZFS-over-FUSE; see see http://www.wizy.org/wiki/ZFS_on_FUSE) on Linux
- installable ZFS/FUSE packages are available e.g. on latest Ubuntu und Fedora (see http://www.linux-magazine.com/w3/issue/103/ZFS.pdf)
Ext4
- fairly new in Linux kernel (since 2.6.27 or so); ext4 is based on ext3 (same developers)
- becoming the default of new versions of Linux distros (Fedora, Ubuntu, ...)
- no 16 GB limitation
- no compression and checksumming (data-integrity) features
btrfs
- latest addition to native Linux filesystems; considered stable since 2.6.31 kernel (http://www.h-online.com/open/Kernel-Log-2-6-31-Tracking--/features/113671)
- (optional) transparent compression
- checksumming for data integrity is implemented
- a review of btrfs from an ex-ZFS engineer: http://lwn.net/Articles/342892/
- you can upgrade an existing linux file system to btrfs without destroying the existing fs or duplicating the data: http://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3
- http://www.h-online.com/open/The-Btrfs-file-system--/features/113738