Sean O Sullivan seanos@seanos.net wrote:
System : CentOS 4.2 2.6.9-22.0.1.ELsmp System fully up-to-date. 3GB RAM 3ware 9000S card, with Raid5 array. I think that's about all relevant info ...
You have the latest 9.2.1.1 3Ware firmware release, correct? And the latest driver for that release, correct?
Had file on disk (not array), attempted to mv file to array. Went fine till 2.4GB was copied, then it slowed down to a meg every few minutes. Free memory was ~50MB (Typically is 1.5-2GB), and cache was 2.5GB. Stopped the move, however cache not being cleared out -- and this issue continues to happen - unsure if it was always a problem/known issue, it does however only occur
when
copying a single file > 2.4GB (I have copied 5+GB of 1+GB files in the past without issue).
Hit the 3Ware's knowlegebse on tweaking the kernel buffer settings for your configuration. They are extremely helpful/useful in this regard. You might have to play with a few settings before it works the most ideal.
Also, saw following in dmesg while this was going on: Out of Memory: Killed process 12467 (mysqld). I'll be restarting server later on tonight, which will 'fix' immediate problem, however just curious on thoughts in regards to this.
Again, everytime I run into this, I hit 3Ware's knowlegebase and find some settings that I play with and they not only solve the problem, but increase performance. And if it persists, you'll be ready to talk to their tech support.
A good whitepaper to read on 3Ware 9000 series cards on kernel 2.6 (applicable to your CentOS 4.2 system) is here: http://www.3ware.com/kb/attachments/Linux2.6WP_0701.pdf