Well, maybe some of you guys have experienced unusual high io times on a RedHat Server with Enterprise 3, well , I had (hopefully) my share of that during these past days.

The server is a Dual Pentium Xeon 2.4Ghz with 1Gb Ram and two SATA Hard Drives of 100GB of space each, no Raid or anything like that, i use it for a Plesk Reloaded 7.53 hosting service, currently hosting over 130 Domains which is not that much really. I started to have terrible problems with server slowness, mostly while performing intensive disk functions, like for example a Plesk upgrade or running the plesk backup utility which currently holds around 9GB of data using psadump. Initially i kind of thought there was a problem with the hard drive, but after reading a lot on google results, i found that literally thousands of people have had similar experiences.

The server was using smp version of the kernel kernel-smp-2.4.21-9.EL , which after reading a lot seems to have some issues handling resources on certain controllers, the server motherboard is an intel , im not sure of the chipset (sorry), but if you really need to know i will find that out.

Yesterday (May 20, 2005) , i upgraded the kernell to version kernel-smp-2.4.21-32.EL , downloaded it from redhat network and since then have been doing some intensive testing with big operations like the psadump, using a bash ftp script to transsfer over 10GB of data and the iotimes have normalized, consider that before my iowait times were around 320%, just crazy, and now its around 20% - 53% while doing such operations, server load average also normalized, before my load average was around 10 ! , or more !

Heres a copy of my top header:

13:56:34 up 38 min, 2 users, load average: 0.12, 0.10, 0.15
124 processes: 122 sleeping, 1 running, 0 zombie, 1 stopped
CPU states: cpu user nice system irq softirq iowait idle
total 2.8% 0.0% 4.8% 0.4% 0.0% 17.6% 372.8%
cpu00 0.1% 0.0% 0.1% 0.0% 0.1% 0.1% 99.2%
cpu01 2.7% 0.0% 4.7% 0.0% 0.0% 0.1% 92.2%
cpu02 0.0% 0.0% 0.0% 0.0% 0.0% 8.9% 91.0%
cpu03 0.1% 0.0% 0.1% 0.5% 0.0% 8.5% 90.4%
Mem: 1024880k av, 990500k used, 34380k free, 0k shrd, 65636k buff
426320k actv, 392832k in_d, 14212k in_c
Swap: 2554324k av, 21416k used, 2532908k free 595668k cached

So, all in all guys, i think is worth to try the kernell upgrade, really, ill keep you posted on the next few days results.