Hello Everyone,
I hope this is the best forum for this question.

So here it is, I have a fileserver setup on Ubuntu Server 9.10 AMD64.
In this system is 4 1.5TB SATAII drives.
They are configured in RAID5 using MD.

Now everything is working beautify, except when you need to create a directory. When you do, the system hangs for about 30 seconds. The I/O wait in top jumps up as well. Then the directory is created and everything works once again.

The odd part is it is only Directory creation that does this. I can copy, move, download and stream files off the server perfectly.

I am baffeled as to what is causing it.

It might be related to the fact that I expanded the array from 3 to 4 drives, it was after that, that I first noticed the problem.

If anyone one has any advise, it would be much apprechated. I can post what ever info you require.

Thanks in advance.
Robert

There may be two reasons of this behaviour I can think of:

1. First - filesystem related. Write what fs is it, check dmesg output just after directory creation etc., but this is wrong way to go, because

2. Second - strange delays are *ALWAYS* DNS-related. Or NIS-related. And 30-second delay is like a fingerprint. And this is Ubuntu, so I am pretty sure about this. Check your NIS configuration: /etc/nssswitch.conf /etc/yp.conf etc. Unfortunatelly I have solved such problem only once and about two years ago and didn't have to do with Ubuntu server since.

Good luck,
backblaze.pl - reliable, hassle-free online backup

Many Many Thanks!

I dug around and found the nis config, it looked good so I kept digging and ended up at the resolv.conf.

There were two lines
domain something.com
search something.com

and then a bunch of nameserver addresses.

So i deleted the Domain and Search and bang, problem gone.

Again, thanks a million
Bob