Lines Matching +full:off +full:- +full:on +full:- +full:delay +full:- +full:us
1 .. SPDX-License-Identifier: GPL-2.0
9 (64 bit) in keeping with increasing disk capacities and state-of-the-art
12 Mailing list: linux-ext4@vger.kernel.org
23 - The latest version of e2fsprogs can be found at:
35 - Create a new filesystem using the ext4 filesystem type:
37 # mke2fs -t ext4 /dev/hda1
41 # tune2fs -O extents /dev/hda1
46 # tune2fs -I 256 /dev/hda1
48 - Mounting:
50 # mount -t ext4 /dev/hda1 /wherever
52 - When comparing performance with other filesystems, it's always
59 '-o barriers=[0|1]' mount option for both ext3 and ext4 filesystems
61 it is often worthwhile to try changing the data journaling mode; '-o
67 metadata-intensive workloads.
73 -------------------
77 * extent format more robust in face of on-disk corruption due to magics,
79 * improved file allocation (multi-block alloc)
82 * inode version field on disk (NFSv4, Lustre)
94 * Case-insensitive file name lookups
95 * file-based encryption support (fscrypt)
96 * file-based verity support (fsverity)
101 case-insensitive file name lookups
104 The case-insensitive file name lookup feature is supported on a
105 per-directory basis, allowing the user to mix case-insensitive and
106 case-sensitive directories in the same filesystem. It is enabled by
108 case-insensitive string match operation is only defined when we know how
110 case-insensitive directories, the filesystem must have the
111 casefold feature, which stores the filesystem-wide encoding
113 Unicode (12.1.0, by the time of this writing), encoded in the UTF-8
118 The case-awareness is name-preserving on the disk, meaning that the file
119 name provided by userspace is a byte-per-byte match to what is actually
123 used on large case-insensitive directories with DX feature. On DX
126 impact on where the directory entry is stored.
136 operate on that file, but the case-insensitive lookups won't work.
167 Don't load the journal on mounting. Note that if the filesystem was
191 performance, but it's good for data-safety. Setting it to 0 will have
194 delayed allocation even older data can be lost on power failure since
201 which can support barriers, and if jbd gets an error on a barrier
203 proper on-disk ordering of journal commits, making volatile disk write
205 battery-backed in one way or another, disabling barriers may safely
212 that ext4's inode table readahead algorithm will pre-read into the
229 errors=remount-ro
230 Remount the filesystem read-only on an error.
233 Keep going on a filesystem error.
264 quota tools to recognize volumes where quota should be turned on. See
265 documentation in the quota-tools package for more details
271 the above quota options. See documentation in the quota-tools package
296 transactions can piggyback on the synchronous write. The algorithm
298 measuring the amount of time (on average) that it takes to finish
303 the max_batch_time, which defaults to 15000us (15ms). This
304 optimization can be turned off entirely by setting max_batch_time to 0.
309 parameter may improve the throughput of multi-threaded, synchronous
310 workloads on very fast disks, at the cost of increasing latency.
323 will detect the replace-via-rename and replace-via-truncate patterns
328 ext3, and avoids the "zero-length" problem that can happen when a
341 minimizes the impact on the system performance while file system's
347 devices and sparse/thinly-provisioned LUNs, but it is off by default
351 Disables 32-bit UIDs and GIDs. This is for interoperability with
352 older kernels which only store and expect 16-bit values.
355 These options enable or disable the in-kernel facility for tracking
357 allows multi- block allocator and other routines to notice bugs or
366 mutex, which improves scalability on high speed storages. However this
369 used for extent-based files. Because of the restrictions this options
370 comprises it is off by default (e.g. dioread_lock).
381 Enable 64-bit inode version support. This option is off by default.
390 blk-crypto framework rather than filesystem-layer encryption. This
391 allows the use of inline encryption hardware. The on-disk format is
393 Documentation/block/inline-encryption.rst.
403 mode - metadata journaling. A crash+recovery can cause incorrect data to
431 /proc/fs/ext4 based on its device name (i.e., /proc/fs/ext4/hdc or
432 /proc/fs/ext4/dm-0). The files in each per-device directory are shown
445 /sys/fs/ext4 based on its device name (i.e., /sys/fs/ext4/hdc or
446 /sys/fs/ext4/dm-0). The files in each per-device directory are shown
451 (see also Documentation/ABI/testing/sysfs-fs-ext4)
454 This file is read-only and shows the number of blocks that are dirty in
459 Tuning parameter which (if non-zero) controls the goal inode used by
461 This is intended for debugging use only, and should be 0 on production
466 blocks that ext4's inode table readahead algorithm will pre-read into
470 This file is read-only and shows the number of kilobytes of data that
475 out before move on to another inode.
507 This file is read-only and shows the number of kilobytes of data that
523 ext4-specific functionality. An incomplete list of these ioctls is shown in the
524 table below. This list includes truly ext4-specific ioctls (``EXT4_IOC_*``) as
525 well as ioctls that may have been ext4-specific originally but are now supported
573 This ioctl operates on the filesystem itself. It converts (migrates)
583 Force all of the delay allocated blocks to be allocated to preserve
584 application-expected ext3 behaviour. Note that this will also start
611 useful links: https://fedoraproject.org/wiki/ext3-devel