作者ping990579 (小山青)
看板Grad-ProbAsk
标题[理工] 103交大资联计系i-node
时间Mon Oct 31 22:46:07 2022
Consider a file system that uses i node-like structure (combined scheme with
multilevel indices) to represent files. Disk blocks are 8-KB in size and a
pointer to a disk block requires 4 bytes. To record a file, this file system
has 12 pointers in the primary index block, composed of 9 direct block pointers, and a single, a double, and a triple indirect
block pointers. the space of other indirect index blocks is fully used to
store pointers. If we want to access the first to the 5120 logical disk
blocks of a file, how many physical disk blocks must be read from the disk?
(Hint: please take into account the primary and other index blocks)
(A) 5120
(B)5121
(C) 5123
(d) 5125
(E) None of the above number is correct
https://imgur.com/a/Q5fgqFy
请问是哪里有算错吗
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※ 编辑: ping990579 (123.241.202.132 台湾), 10/31/2022 22:49:14
1F：→ me356500: 少一个access primary吧 11/01 14:28
2F：推 bettyteng21: 5124加上最一开始的，就是5125 11/28 18:15
有点听不太懂，我後来爬到有人也问一样的问题，我一开始是这样算的，总共循序5120
个，这5120个会在两层的第二块里面，所以我原本是5120+一次(存取single)+一次(存取
double)+一次(double的第一块)+一次(double的第二块)=5124，但好像还要再额外一次
存取double，所以总共5125，这样不知道对不对
※ 编辑: ping990579 (116.241.187.215 台湾), 12/15/2022 20:52:03