Philip Gwyn liste@artware.qc.ca writes:
Hello,
I have strange behaviour on a server that I can't get a handle on. I have a reasonably powerful server running VMware server 1.0.4-56528. It has a RAID5 build with mdadm on 5 SATA drives. Masses of ram and 2 XEON CPUs. But it stutters.
...
The problem seems like a disk problem. I grow to suspect that SATA isn't ready for the big time. I also grow to dislike RAID5.
Personally, I will use RAID5, and I will use SATA, but I will not use SATA with RAID5 except in 'tape replacement' roles. The weak bits of RAID5 (read/ write cycle on sub-stripe writes) are often exasterbated by the weak bits of SATA (slow seek time, slow rotational speed) creating a perfect storm of suck.
Not to say that's your primary problem.
Actually, it sounds a whole lot like the problems I get with xen on heavily used servers, if I don't assign a core exclusively to the dom0 (or at least give it a very high priority.) But I have little knowledge of or experience with VMware, so I don't know if you have a similar problem.