Lines Matching full:block
35 A file system is described by its super-block,
37 Because the super-block contains critical data,
40 since the super-block data does not change,
42 or other hard disk error causes the default super-block
49 the minimum size of a file system block is 4096 bytes.
52 The block size of a file system is recorded in the
53 file system's super-block
54 so it is possible for file systems with different block sizes
56 The block size must be decided at the time that
66 that includes a redundant copy of the super-block,
84 could cause the loss of all redundant copies of the super-block.
92 or platter can be lost without losing all copies of the super-block.
99 out with its super-block at the ``known'' location,
104 the cylinder group information begin on a file system block boundary.
105 To start the cylinder group on a file system block boundary,
106 file systems with block sizes larger than 8 kilobytes
108 the boot block and the beginning of the cylinder group.
121 By increasing the block size, disk accesses in the new file
131 A uniformly large block size wastes space.
133 block size on the amount of wasted space in the file system.
149 828.7 Mb 6.9 Data + inodes, 512 byte block UNIX file system
150 866.5 Mb 11.8 Data + inodes, 1024 byte block UNIX file system
151 948.5 Mb 22.4 Data + inodes, 2048 byte block UNIX file system
152 1128.3 Mb 45.6 Data + inodes, 4096 byte block UNIX file system
154 Table 1 \- Amount of wasted space as a function of block size.
159 As the block size on the disk
166 of a single file system block into one or more
170 each file system block can optionally be broken into
175 The block map associated with each cylinder group
178 to determine if a block is available, aligned fragments are examined.
187 Block numbers 0 1 2 3
198 Fragments of adjoining blocks cannot be used as a full block,
201 fragments 6\-9 cannot be allocated as a full block;
202 only fragments 12\-15 can be coalesced into a full block.
204 On a file system with a block size of 4096 bytes
207 and possibly a single fragmented block.
208 If a file system block must be fragmented to obtain
210 the remaining fragments of the block are made
215 three fragment portion of another block.
216 If no block with three aligned fragments is
218 a full size block is split yielding the necessary
234 block or fragment to hold the new data.
238 block in the file
240 If space exists in a block already allocated,
243 a full block of data, a full block is allocated and
244 the first full block of new data is written there.
245 This process is repeated until less than a full block
248 fit in less than a full block,
249 a block with the necessary fragments is located,
250 otherwise a full block is located.
256 already in the fragments exceeds the size of a full block,
257 a new block is allocated.
259 to the beginning of the block
260 and the remainder of the block is filled with new data.
263 fit in less than a full block,
264 a block with the necessary fragments is located,
265 otherwise a full block is located.
272 fragmented block expands to a full block.
274 if the user program writes a full block at a time,
275 except for a partial block at the end of the file.
276 Since file systems with different block sizes may reside on
280 For files the optimal size is the block size of the file system
297 block UNIX file system.
307 equals an old file system's block size.
367 on the same cylinder as the previous block in the same file.
371 it can be a consecutive block
372 or a rotationally delayed block
389 the number of milliseconds required to skip over a block.
393 Given a block allocated to a file,
395 skip over so that the next block in the file will
411 The super-block contains a vector of lists called
415 lists the index into the block map for every data block contained
417 When looking for an allocatable block,
419 position with a non-zero block count.
422 only the relevant parts of the block map to find a free block.
435 on nearly every block.
452 They also calculate rotationally optimal block layouts,
521 redirect block allocation
527 at which a file on a 4096 byte block file system first
528 requires a single indirect block. This appears to be
529 a natural first point at which to redirect block allocation.
531 forcing block allocation to be redirected when a
547 always allocate the requested block
549 allocates a free block of the requested size that is
550 rotationally closest to the requested block.
558 If a requested block is not available, the local allocator uses
561 Use the next available block rotationally closest
562 to the requested block on the same cylinder. It is assumed
570 use a block within the same cylinder group.
574 another cylinder group to look for a free block.