bad performance with ext4

[zerokawa]

Hello,
i create a new virtual machine.
Diskwrite with 1MB/s.
See screenshot with bad speed.



My image was before ntfs partition. So I reached up to 50MB / s when installing Windows.
In the version 2.3 but no vm starts with ntfs.
Poor performance with ext4.

Someone has an idea

System partition is a single disk
My image partition is ext4 with three hard drives in a software raid five.

Is the cause the software raid?

 

[tom]

software raid is not recommended and not known to be fast.

you can do a simple benchmark on the host (but only when the host is idle).

pveperf

and post the config for your VM:

qm config 304

as soon as your windows box is installed, run a benchmark inside (CrystalDiskMark).

see my screenshot.



the installation of a Win7 takes about 8 minutes on this host (locally stored qcow2 files, ext4)
(Fast Adaptec Raid Controller (6805) but 5 years old hard disks)

 

[zerokawa]

I change the partition to qcow2 is better with performance.

pveperf

CPU BOGOMIPS: 39782.22
REGEX/SECOND: 886754
HD SIZE: 94.49 GB (/dev/mapper/pve-root)
BUFFERED READS: 88.42 MB/sec
AVERAGE SEEK TIME: 13.00 ms
FSYNCS/SECOND: 1276.05
DNS EXT: 35.95 ms
DNS INT: 34.36 ms

bad performance with vmdk

qm config 302

balloon: 512
bootdisk: sata0
cores: 6
memory: 1024
name: CL1
net0: e1000=A6:A3:40:89:59:5B,bridge=vmbr0
ostype: win7
sata0: local4:302/vm-302-disk-1.vmdk,size=32G
sata1: local2:iso/Original_Win7_pro_x64.iso,media=cdrom,size=3191550K
sockets: 1

I broke the installation with vmdk.


A screenshot of cristal mark disk and partition with qcow2.




My virtual machines run again.

There is a command to convert an existing vm config with vmdk to qcow2?

 

[tom]

...
There is a command to convert an existing vm config with vmdk to qcow2?

try qemu-img

see 'man qemu-img'

 

[zerokawa]

Hi,

thanks for help and the tip