Progress DB Block Size vs NTFS Block Size

[Adam Whipp]

Hi Everyone,

We currently have a 4K database block on the default NTFS block size of 4K. Our application vendor is telling us to change to 8K database block for better performance (which I can understand), but they are also telling us to use an NTFS block size of 64K or 128K at the same time. From my understanding, this is bad. I keep seeing that you want to make the NTFS block size equal with the database block size, and NEVER do what he is suggesting to me. I questioned him on this, and he says "I know Progress says not to do this, but I think it is better". I don't feel good about this simply because he thinks its better. Does anybody run this way, or am I correct that the NTFS block size should NEVER being larger than the database block size? Thanks in advance!

Adam Whipp

 

[TomBascom]

Perhaps he is getting confused with setting a stripe size on a RAID? (Large stripe sizes do seem to work best.)

The traditional advice is that filesystem block size should be the same as, or smaller than, db block size. But... that is based on the way that old, block oriented, filesystems work. Newer, journaled, filesystems don't really work that way anymore.

Your vendor says that he knows that Progress says not to do what he is suggesting. He "thinks" that it will be better? Could he maybe back that up with some testing?

I think that it might be kind of interesting to do some testing and get to the bottom of it. But I would also point out that it would be lower on my priority list than a whole bunch of other performance tuning possibilities. For instance... are you using type 2 storage areas?

 

[Adam Whipp]

We have been investigating type 2 storage areas. We talked to the application vendor, and they are supposed to be getting some information back to us about whether or not they officially support type 2 and how to go about converting.

 

[TomBascom]

If they're pushing weird NTFS block sizes but aren't sure about type 2 areas there is a serious priorities disconnect going on...

All Progress applications that can run on OpenEdge 10 support type 2 areas (which is to say all Progress applications... but that's another discussion...). Some partners just don't know it yet.

Converting requires a dump & load. You should do some planning regarding what the new target system should look like first. There are a number of threads kicking around here that discuss some of the considerations.