Lines Matching +full:many +full:- +full:to +full:- +full:many

1 .. SPDX-License-Identifier: GPL-2.0
4 ------
9 .. list-table::
11    :header-rows: 1
13    * - Group 0 Padding
14      - ext4 Super Block
15      - Group Descriptors
16      - Reserved GDT Blocks
17      - Data Block Bitmap
18      - inode Bitmap
19      - inode Table
20      - Data Blocks
21    * - 1024 bytes
22      - 1 block
23      - many blocks
24      - many blocks
25      - 1 block
26      - 1 block
27      - many blocks
28      - many more blocks
31 to allow for the installation of x86 boot sectors and other oddities.
33 happens to be (usually 0). However, if for some reason the block size =
39 superblock and group descriptors are written to some of the block groups
46 of the block bitmaps to allow for future expansion of the filesystem. By
47 default, a filesystem is allowed to increase in size by a factor of
51 is continuous range of blocks large enough to contain
58 bitmaps to come after the inode table, or for both to be in different
63 ---------------------
68 first block group of the flex_bg are expanded to include the bitmaps
71 superblock, group descriptors, data block bitmaps for groups 0-3, inode
72 bitmaps for groups 0-3, inode tables for groups 0-3, and the remaining
73 space in group 0 is for file data. The effect of this is to group the
74 block group metadata close together for faster loading, and to enable
75 large files to be continuous on disk. Backup copies of the superblock
81 -----------------
85 128MiB(2^27 bytes) block group size and 64-byte group descriptors, ext4
87 filesystem size to 2^21 * 2^27 = 2^48bytes or 256TiB.
89 The solution to this problem is to use the metablock group feature
91 META_BG feature, ext4 filesystems are partitioned into many metablock
100 to the hard limit 2^32, allowing support for a 512PiB filesystem.
103 the superblock is followed by a variable-length set of block group
106 groups in a meta-block group. A meta-block group is a collection of
109 bytes, a meta-block group contains 16 block groups for filesystems with
112 descriptor layout, or existing filesystems can be resized on-line, and
120 -------------------------------
123 enable mkfs to skip initializing other parts of the block group
126 therefore the on-disk bitmap blocks are not initialized. This is
128 only fixed-location block group metadata. The INODE_ZEROED flag means
130 rely on the kernel to initialize the inode tables in the background.
132 By not writing zeroes to the bitmaps and inode table, mkfs time is