Advice for Shared Hosting

[sahostking]

Hi Guys

So our current spec of servers are the following:

Intel Xeon E5-2620 2.4GHz
64GB Memory ECC
HW RAID 10
6 x 2TB Enterprise SATA Disks

We currently host 3 cPanel servers with around 500 accounts each on these Nodes.
It seems to be getter slower and iowait seems to go up at times.

On the node the iowait is very low at 0.5 or so usually but on the VMs it gets to 22 to 40 sometimes during the busy time of the day. The Node CPU however goes up to 9.0 at times. Is this maybe just requiring us to add another processor to it? then we have 2 processors to it.

If all else fails we'd like to move to SSD as we think this may improve it alot. Though the cost is substantially more so we'd like to get this right.

We are considering the same spec servers except the drives would be different.

6x 1TB Crucial SSD ZFS Raid 10

Will this work better or should we choose different raid type?

Also note all our VMs are KVM.

Alternatively should we just go for half the price option for a duplicate of our initial spec and just take some a busy VM off and place it on the new one. I assume that would be better?

Also is this better? Intel Xeon E5-1620 3.5GHz (8 cores) or Intel Xeon E5-2620 2.4GHz (12 cores)

Thanks.

 

[sdinet]

So these cPanel servers are hosted as VMs in your PvE?
"Node CPU however goes up to 9.0 at times." Why is 9 a big deal? Or do you mean 90%?
I use hardware RAID in all my deployments. I have heard nothing but bad things about using software RAID.
Do you have 3 physical servers, each with a cPanel VM? setup unclear-please elaborate.
I just want to know because you need to determine if its a CPU bottleneck, memory or storage performance bottleneck.

 

[sahostking]

When top shows 9 and above it gets very sluggish and lsphp as we have litespeed on starts piling up and so does mysql queries in mysqladmin. I am thinking that even though we use hw raid 10 with 6 disks the IOPs are probably not enough to keep up. We have 3 cpanel servers per node with 500 accounts each.

Starting to think SSD is our only option.