physical disk to vm (kvm) error on encrypted disk

[gandalfk7]

hi!
I wanted to map a physical disk to one of my vms, a kvm one.
I used the command

qm set 100 -sata0 /dev/disk/by-uuid/MYUUID

the usb disk is encrypted with luks

the error I get is:

[FONT=tahoma]kvm:[/FONT][FONT=tahoma] -drive file=/dev/disk/by-uuid/MYUUID,if=none,id=drive-sata0,aio=native,cache=none: could not open disk image /dev/disk/by-uuid/MYUUID: Invalid argument
TASK ERROR: start failed: command '/usr/bin/kvm -id 100 -chardev 'socket,id=qmp,path=/var/run/qemu-server/100.qmp,server,nowait' -mon 'chardev=qmp,mode=control' -vnc unix:/var/run/qemu-server/100.vnc,x509,password -pidfile /var/run/qemu-server/100.pid -daemonize -name gnd-deb02 -smp 'sockets=1,cores=1' -nodefaults -boot 'menu=on' -vga cirrus -k it -m 2048 -cpuunits 1000 -device 'piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2' -device 'usb-tablet,id=tablet,bus=uhci.0,port=1' -device 'virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3' -drive 'file=/var/lib/vz/images/100/vm-100-disk-1.qcow2,if=none,id=drive-ide0,format=qcow2,aio=native,cache=none' -device 'ide-hd,bus=ide.0,unit=0,drive=drive-ide0,id=ide0,bootindex=100' -device 'ahci,id=ahci0,multifunction=on,bus=pci.0,addr=0x7' -drive 'file=/dev/disk/by-uuid/MYUUID,if=none,id=drive-sata0,aio=native,cache=none' -device 'ide-drive,bus=ahci0.0,drive=drive-sata0,id=sata0' -netdev 'type=tap,id=net0,ifname=tap100i0,script=/var/lib/qemu-server/pve-bridge' -device 'e1000,mac=MYMACADDRESS,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300'' failed: exit code 1
[/FONT]

I can't understand what I am doing wrong,
on another host I already did it with a non encrypted disk,
the operation above should map the UUID to the vm and I should do all the encryption tasks on the vm, right?

I already tried virtio0 and ide1, my configfile of the vm:

bootdisk: ide0
cores: 1
ide0: local:100/vm-100-disk-1.qcow2,format=qcow2,size=32G
memory: 2048
name: gnd-deb02
net0: e1000=MYMACADDRESS,bridge=vmbr0
ostype: l26
sockets: 1
sata0: /dev/disk/by-uuid/MYUUID,size=2861556M

thank you very much

Matteo

 

[dietmar]

Please try another cache setting (writeback) for that disk.

 

[gandalfk7]

Please try another cache setting (writeback) for that disk.

the setting I have to change is "cache=writeback",
would it be ok to do:

sata0: /dev/disk/by-uuid/MYUUID,[B]cache=writeback[/B],size=2861556M

thank you


Matteo

 

[dietmar]

You can change that on the GUI.

 

[dietmar]

the setting I have to change is "cache=writeback",
would it be ok to do:

sata0: /dev/disk/by-uuid/MYUUID,[B]cache=writeback[/B],size=2861556M

looks correct to me.

 

[gandalfk7]

You can change that on the GUI.

hi!
I changed the cache to cache=writeback via GUI and now it works correctly!
thank you very much!!

before it was in default = none,
do you know why it wasn't working?

thank you again!


Matteo

 

[dietmar]

before it was in default = none,
do you know why it wasn't working?

Semms the disk (encrypted with luks) does not support the O_DIRECT flag ("man 2 open").