Filesystems: Difference between revisions

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Filesystems (edit)

Revision as of 22:23, 28 November 2016

282 bytes removed , 28 November 2016

→‎Ext4

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 == XFS ==
 * SGI's filesystem (1994) that was ported to Linux around 2001
-* no 16 GB limitation
+* no 16 TB limitation; max size is 8 Eib (1 exbibyte = 2^60 bytes)
-* no compression and checksumming (data-integrity) features
+* no data compression and checksumming (data-integrity) features. It does have metadata checksums.
+* the default for RHEL starting at version 7
-== Ext3 ==
-* fairly old (2001), but well established and well behaved
-* does not support more than 16GB (2^36 bytes)
-* does not support transparent compression
-* does not support checksumming (a data-integrity feature)
 == ZFS ==
 * Sun's filesystem which is natively available on Solaris (since 2005)) and OpenSolaris (both of which are freely available)
-* no 16 GB limitation; max size is 2^128 bytes
+* no 16 TB limitation; max size is 2^128 bytes
 * (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
+* triple parity raid (raidz3) has been added to ZFS [http://blogs.sun.com/ahl/entry/triple_parity_raid_z]
-* 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
+* there is a port of ZFS to FreeBSD
-* installable ZFS/FUSE packages are available e.g. on latest Ubuntu und Fedora (see http://www.linux-magazine.com/w3/issue/103/ZFS.pdf)
+* the source code license of ZFS is incompatible with the GPL of the Linux kernel, therefore not in the latter
+* install from http://zfsonlinux.org/
 == Ext4 ==
-* fairly new in Linux kernel (stable since 2008); ext4 is based on ext3 (same developers)
+* ext4 is based on ext3 (same developers)
-* becoming the default of new versions of Linux distros (Fedora, Ubuntu, ...)
+* default of some Linux distros
-* no 16 GB limitation; max size is 1 EiB (1 exbibyte = 2^60 bytes)
+* no 16 TB limitation; max size is 1 EiB (1 exbibyte = 2^60 bytes)
 * no compression and checksumming (data-integrity) features
 == btrfs ==
 * latest addition to native Linux filesystems; considered stable since 2.6.31 kernel (2009; see http://www.h-online.com/open/Kernel-Log-2-6-31-Tracking--/features/113671)
-* no 16 GB limitation; max size is 16 Eib (1 exbibyte = 2^60 bytes)
+* no 16 TB limitation; max size is 16 Eib (1 exbibyte = 2^60 bytes)
 * (optional) transparent (zlib) compression
 * checksumming for data integrity is implemented