Disk Block Size Question (AREV Specific)
At 28 JAN 1999 11:49:05AM Cory Sharshel wrote:
I am changing a netware 3.12 server from a P90 with 96Mb/4Gb to a P450 with 256Mb/18Gb. Does the block size of the netware volume make any difference in arev performance? We have always used the default 4K but are wondering if disk I/O would improve with a higher block size such as 16K. Any thoughts would be appreciated.
Cory Sharshel
Systems Analyst
Ultimate Support Systems
corys@ultimatesupport.com
970-493-4488
At 28 JAN 1999 12:28PM Steve Smith wrote:
There are other factors such as packet size which are probably more of a constraint. I seem to recall seeing that Novell filing system self-optimizes for fragmentation as it goes, so this proably is not an issue. Remember that if your average block size is 4 kB you lose and average of 2 kB per file on disk. Larger block sizes will chew up your disk faster if you have a lot of small files.
Steve
At 01 FEB 1999 07:53PM Chris Vaughan wrote:
There are two situations where I could see some gain:
1. When files are processed in physical order - (ie unordered select)
2. Files with a large average record size and a frame size set to match.(I think 4K is the max for RTP57 frames - default is 1K).
As neither of these situations is the norm in transaction processing systems, I reckon that overall gains would be minimal.
There would be space the overhead of minimum 4k allocation and extension for both LK and OV portion of every data file and its dictionary. But what the heck - disk space is cheap.
However, I don't see that there is any other real down side. Other non Arev apps might get some great benefits.