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[mathalor]

Page No:190 Q.no:8 gate 2004(IT)

In a particular UNIX OS, each data block is of size 1024 bytes,each node has 10 direct data block address and three additional addresses:one for single indirect address,one for double indirect block,one for triple indirect block.
Also each block can contain addresses for 128 blocks.which one of the following is approximately the maximum size of a file.

a)512 MB
b)2GB
3) 8GB
d)16GB

Anyone can explain the solution!

[mpkpawan07]

answer is B
let me know if my answer is correct or not please.
to know how to solve these kind of problems please refer to THIS post

[mathalor]

I don't know what is correct option, but i am also getting the same i.e 2 GB

let me know the way to calculate pointer/block in this problem is as follows or not............

the total no of direct pointers in a block is= 1024*128/1024= 128

Is this correct or not?

[mpkpawan07]

let me know the way to calculate pointer/block in this problem is as follows or not............

hey the number of pointers/block in this question has been given to be 128, so you need not do all that!
but the post to which i directed you does not explicitly mention the number of pointers/block, and that is why i calculated!
hope you understand! :)

[mathalor]

ok!

thanks

[monika17ap]

A UNIX file system has 1-KB blocks and 4-byte disk address. What is the maximum file size if i-nodes contain 10 direct entries, and one single, double and triple indirect entry each?

the above question and your questions are whether same..??

If the answer of this question is 2GB..then can you explain, plz..

[sameer2009]

A UNIX file system has 1-KB blocks and 4-byte disk address. What is the maximum file size if i-nodes contain 10 direct entries, and one single, double and triple indirect entry each?
the above question and your questions are whether same..??

here disk address size is 4B

In a particular UNIX OS, each data block is of size 1024 bytes,each node has 10 direct data block address and three additional addresses:one for single indirect address,one for double indirect block,one for triple indirect block.
Also each block can contain addresses for 128 blocks.which one of the following is approximately the maximum size of a file.
here disk address size = x
1024/x = 128
x = 8B

[monika17ap]

ok..
and above given question's ans is 2GB??

[sameer2009]

A UNIX file system has 1-KB blocks and 4-byte disk address. What is the maximum file size if i-nodes contain 10 direct entries, and one single, double and triple indirect entry each?

block = 2^10
block pointer size = 4B
entries possible in block = 2^10 / 2^2 = 256
direct pointer gives = 10 * 256 = 10 blocks
single indirect gives = 256 * 256 = 2^8 blocks
double indirect gives = 256 * 256 * 256 = 2^16 blocks
triple indirect gives = 256 * 256 * 256 * 256 = 2^14 blocks
total = 16777546 blocks = 16777546 * 1024 = 17180207104 ~ 16 GB

In a particular UNIX OS, each data block is of size 1024 bytes,each node has 10 direct data block address and three additional addresses:one for single indirect address,one for double indirect block,one for triple indirect block.
Also each block can contain addresses for 128 blocks.which one of the following is approximately the maximum size of a file.

block = 2^10
block pointer size = 1024/128 = 8
entries possible in block = 2^10 / 2^3 = 128
direct pointer gives = 10 * 128 = 10 blocks
single indirect gives = 128 * 128 = 2^7 blocks
double indirect gives = 128 * 128 * 128 = 2^14 blocks
triple indirect gives = 128 * 128 * 128 * 128= 2^21 blocks
total = 16777546 blocks = 16777546 * 1024 = 17180207104 ~ 16 GB
total = 2113674 blocks = 2113674 * 1024 ~ 2GB