Lines Matching +full:d +full:- +full:cache +full:- +full:block +full:- +full:size
15 set using tune2fs(8). Kernel-determined defaults are indicated by (*).
23 dax Use direct access (no page cache). See
30 errors=remount-ro Remount the filesystem read-only on an error.
36 nouid32 Use 16-bit UIDs and GIDs.
38 oldalloc Enable the old block allocator. Orlov should
39 have better performance, we'd like to get some
41 orlov (*) Use the Orlov block allocator.
81 ------
84 a fixed size, of 1024, 2048 or 4096 bytes (8192 bytes on Alpha systems),
87 and also impose other limits on the size of files and the filesystem.
89 Block Groups
90 ------------
92 Blocks are clustered into block groups in order to reduce fragmentation
94 of consecutive data. Information about each block group is kept in a
95 descriptor table stored in the block(s) immediately after the superblock.
96 Two blocks near the start of each group are reserved for the block usage
98 are in use. Since each bitmap is limited to a single block, this means
99 that the maximum size of a block group is 8 times the size of a block.
101 The block(s) following the bitmaps in each block group are designated
102 as the inode table for that block group and the remainder are the data
103 blocks. The block allocation algorithm attempts to allocate data blocks
104 in the same block group as the inode which contains them.
107 --------------
113 the superblock are stored in block groups throughout the filesystem.
115 every block group, along with backups of the group descriptor block(s).
123 how many inodes and blocks are in each block group, when the filesystem
129 such as a volume name, a unique identification number, the inode size,
137 ------
144 group, flags, size, number of blocks used, access time, change time,
151 bits of the file size if the inode is a regular file (allowing file sizes
160 in the inode. There is a pointer to an indirect block (which contains
161 pointers to the next set of blocks), a pointer to a doubly-indirect
162 block (which contains pointers to indirect blocks) and a pointer to a
163 trebly-indirect block (which contains pointers to doubly-indirect blocks).
165 The flags field contains some ext2-specific flags which aren't catered
168 behaviour on a per-file basis. There are flags for secure deletion,
169 undeletable, compression, synchronous updates, immutability, append-only,
170 dumpable, no-atime, indexed directories, and data-journaling. Not all
174 -----------
185 block group as the directory in which they are first created.
187 The current implementation of ext2 uses a singly-linked list to store
195 -------------
202 block for the symlink, and most symlinks are less than 60 characters long.
204 Character and block special devices never have data blocks assigned to
209 --------------
212 for a particular user (normally the super-user). This is intended to
213 allow for the system to continue functioning even if non-privileged users
219 ----------------
230 ---------------------
237 revision 1. There are three 32-bit fields, one for compatible features
238 (COMPAT), one for read-only compatible (RO_COMPAT) features and one for
244 but the on-disk format is 100% compatible with older on-disk formats, so
254 An RO_COMPAT flag indicates that the on-disk format is 100% compatible
255 with older on-disk formats for reading (i.e. the feature does not change
256 the visible on-disk format). However, an old kernel writing to such a
265 An INCOMPAT flag indicates the on-disk format has changed in some
270 The COMPRESSION flag is an obvious INCOMPAT flag - if the kernel
287 --------
297 per-file if you have the program source: use the O_SYNC flag to open()
298 per-file if you don't have the source: use "chattr +S" on the file
299 per-filesystem: add the "sync" option to mount (or in /etc/fstab)
305 -----------
307 There are various limits imposed by the on-disk layout of ext2. Other
310 created, and depend upon the block size chosen. The ratio of inodes to
312 increase the number of inodes is to increase the size of the filesystem.
315 Most of these limits could be overcome with slight changes in the on-disk
319 Filesystem block size: 1kB 2kB 4kB 8kB
321 File size limit: 16GB 256GB 2048GB 2048GB
322 Filesystem size limit: 2047GB 8192GB 16384GB 32768GB
324 There is a 2.4 kernel limit of 2048GB for a single block device, so no
326 an upper limit on the block size imposed by the page size of the kernel,
332 There is a "soft" upper limit of about 10-15k files in a single directory
333 with the current linear linked-list directory implementation. This limit
336 (under development) allows 100k-1M+ files in a single directory without
337 performance problems (although RAM size becomes an issue at this point).
340 (imposed by the file size, the realistic limit is obviously much less)
342 enough 4-character names to make up unique directory entries, so they
347 ----------
352 to the on-disk ext2 layout. In a nutshell, the journal is a regular
385 RISC OS client http://www.esw-heim.tu-clausthal.de/~marco/smorbrod/IscaFS/