HFS FILESYSTEM BLOCKS

[so_2]

This query is not a part of problem but is just for my awareness.If i am using HFS with a block size of 8kb how many bytes are read if a 1KB read is requested? Also what fragment size would suit me for maximum disk space utilisation?An explanation from unix gurus are expecting..

thanks
s.o

[Devender Khatana · Accepted solution]

Hi,

One block is the minimum unit in which read is performed. So any read operation will include reading one full block.

Attached is the Unix performance cookbook clarifying a few of similar queries but on JFS flatform.

HTH,
Devender

[Arunvijai_4]

Hello,

Fragmentation for small files are done in 1K (upto 8K), for files > 8K, it is 8K increments.
More information can be seen at,

http://docs.hp.com/en/B3929-90011/ch05s02.html

-Arun

[Steven E. Protter]

Shalom,

Generally a file, whether big or small takes up a block. If you have lots of small files, then smaller block and fragment sizes will mimimize disk utilization. If you have big files, larger block size.

Note: HFS is only required for /stand on HP-UX 11i v1 and before. Almost anything else should be done with JFS vxfs on which the same general principles hold.

SEP

[Arunvijai_4]

Hi,

If you are looking HFS supported sizes, take a look at the attachment.

-Arun

[Arunvijai_4]

Sorry, attachment was missed in my last post.

-Arun

[so_2]

closing. points assigned to all.
thanks.
s.o