Fedora14: Strange and intermittent very slow disks on server

[Ian Chapman]

Hi,


> However, I think I will change the drives. I was hoping to try some WD10EADS
> ones I have, but after your issues I will look at the RE series or
> another make ...

Further to what Lamar has already said. I have a pair of these drives 
running under F14 (originally F13) and I would never buy them again. I 
originally suffered from the 4k partition boundary issue which once 
rectified made an enormous difference. I was running several virtual 
machines and once I started up more than one VM, it took a life time for 
the VM to boot. I was also seeing the same issue with yum, updates 
taking a ridiculous amount of time.

You might also when to check the head load cycle count with smartctl

smartctl -a /dev/sdX | grep Load_Cycle_Count

They have stupidly aggressive power saving which as I understand it 
cause many unnecessary head parks, depending on the workload of your 
system. For example one of my drives hit over 240,000 cycles in 6 months 
before I became aware of it. By comparison another 4 year old drive is 
currently only showing 70,000 cycles. There's a tool from WD which lets 
you alter how aggressively it parks the heads. Unfortunately it's a 
vendor specific setting the firmware so you can't use a standard linux 
util to change it.



-- 
Ian Chapman.