KVM guest installation is a bit slow, how to improve?

Magneto

Well-Known Member
Jul 30, 2017
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Hi,

I wonder if someone can shed some light on this matter.
The environment:

3x Supermicro server with following features per server:
128GB RAM
3x 8TB SATA HDD
2x SSD drives (intel_ssdsc2ba400g4 - 400GB DC S3710)
2x 12 core CPU (Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz
Quad port 10Gbe Inter NIC
2x 10GB Cisco switches (to isolate storage network from LAN)

Installing CentOS 7 with 1523 package (i.e. the Development option on the CentOS 7 ISO), take aprox 18 minutes to install on this cluster.

As a test, to install it on a standalone machine with a hardware RAID controller with RAID1 and 256Mb cache, took 7 minutes - for the same installation.

I am using the VirtIO disk for the Linux VM, with 4 cores and 4GB RAM.

Disk IO, on the host node, spiked at 6.39Mbps during installation.
Network traffic spiked at 12.66Kbps
RAM spiked at 4.13Gb
CPU Usage spiked at 32.73%


Running top on the hostnode I noticed that KVM used 100% CPU, but only on a single core.

root@virt1:~# pveversion -v
proxmox-ve: 5.1-25 (running kernel: 4.13.4-1-pve)
pve-manager: 5.1-36 (running version: 5.1-36/131401db)
pve-kernel-4.13.4-1-pve: 4.13.4-25
pve-kernel-4.10.17-4-pve: 4.10.17-24
pve-kernel-4.10.17-2-pve: 4.10.17-20
libpve-http-server-perl: 2.0-6
lvm2: 2.02.168-pve6
corosync: 2.4.2-pve3
libqb0: 1.0.1-1
pve-cluster: 5.0-15
qemu-server: 5.0-17
pve-firmware: 2.0-3
libpve-common-perl: 5.0-20
libpve-guest-common-perl: 2.0-13
libpve-access-control: 5.0-7
libpve-storage-perl: 5.0-16
pve-libspice-server1: 0.12.8-3
vncterm: 1.5-2
pve-docs: 5.1-12
pve-qemu-kvm: 2.9.1-2
pve-container: 2.0-17
pve-firewall: 3.0-3
pve-ha-manager: 2.0-3
ksm-control-daemon: 1.2-2
glusterfs-client: 3.8.8-1
lxc-pve: 2.1.0-2
lxcfs: 2.0.7-pve4
criu: 2.11.1-1~bpo90
novnc-pve: 0.6-4
smartmontools: 6.5+svn4324-1
zfsutils-linux: 0.7.2-pve1~bpo90
ceph: 12.2.1-pve3

root@virt1:~# pveperf
CPU BOGOMIPS: 211200.00
REGEX/SECOND: 2496022
HD SIZE: 28.67 GB (/dev/mapper/pve-root)
BUFFERED READS: 510.61 MB/sec
AVERAGE SEEK TIME: 0.07 ms
FSYNCS/SECOND: 331.83
DNS EXT: 152.90 ms
DNS INT: 2.68 ms (fermel.co.za)
 

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Last edited:
On what storage you install? From what source you install? Plus, any installation will be single core anyway, so it looks as problem with network or storage.
 
On what storage you install? From what source you install? Plus, any installation will be single core anyway, so it looks as problem with network or storage.
I am installing from an ISO hosted on the proxmox cluster, hosted on glusterfs, to a CEPH storage.
The network is 10Gb and utilization is low.

I find it hard to believe that installation is single threaded. The exact same installation, from a USB memory stick onto a Corei5 desktop PC was 2x faster.