io size,block size,stripe size

[jiangjun]

hi,
When I was learning the HP-UX, who can explain the IO SIZE, BLOCK SIZE, STRIPE SIZE the meaning of?
Performance of these three parameters on what impact, such as my application of IO is the frequent small to read and write operation, I should do to adjust these parameters.

[Steven E. Protter]

Shalom,

I will try in simple english but a link might be better.

IO SIZE = the amount of data in a single IO or Input Output oepration.

BLOCK SIZE = The size of a data block, usually on disk. Bigger blocks can sometimes improve IO performance by allow data to be read with less frequent reads.

STRIPE SIZE = When setting up disk, in a raid configuration the data blocks are spread around in different disks. The size of these blocks is stripe size. This size can effect performance.

Note that for heavy write databases/environments do better with simpler raid 1, configuration. Striping raid 5 makes for more input/output in more disk sections and substantially slows write performance.

Links:
http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1017772
http://archives.postgresql.org/pgsql-performance/2006-07/msg00180.php
http://www.linuxforums.org/forum/coffee-lounge/121795-stripe-size-should-i-use-best-performance.html

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