Promox 4.x to 6.x ZFS high cpu usage

qgrasso

Member
Jul 31, 2013
27
4
23
Queensland, Australia
Hi,

I'm running an old 4.x cluster specifically 4.4-18, I have some servers which are the same specifications which are

Supermicro SYS-1028R-WTR
Dual Xeon E5-2630v4 2.20Ghz CPU's (40 HT Cores)
256GB RAM
8 x 960GB Samsung PM863a's using ZFS RAIDZ+2

I have recently been attempting to install the latest Proxmox 6.1 & 6.2 (latest ISO from the website) and have noticed a significant jump in CPU utilization in ZFS when doing some really basic testing.


I created a new VM using a windows 2019 ISO and gave it 40GB of storage, 4 cores & 4GB Ram along with IOPS and disk limit of 2000 & 200mb/s.


Same VM Specs, on my 4.x box installing windows server the CPU never goes about 10-12% utilization, however with the 6.x both 6.1 & 6.2 ISO's i'm finding the over all system CPU utilization is spiking above 50% or more the system, and the load average is over 7 by the time the install is complete instead of under 3 on my 4.x server and I think the system CPU utilization never got above 17%.


So far I've tried upgrading the system bios to the latest available and tweaking block sizes, usually, on my 4.x servers, i run 32kb block size on my zvol's as it seems to work best for me. None of these changes made any difference in my 6.x installations.


Pool according to tests both are ashift=12

Both have compression enabled the 4.x cluster seems to be using lz4 compression, and the 6.x doesn't seem to say, just says ON.

Any Ideas?

Thanks
 

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