Asynchronous system time (with guest additions)

[Jimini]

Hey there,
I have set up three virtual machines. The host system is Gentoo (2.6.36-gentoo-r5), the guests run Gentoo (2.6.36-hardened-r9), too. Guest additions are installed. On one of the three machines I simply can't synchronize the system time with the hosts time. Sometimes the system has a drift of about 6 minutes, then, after a reboot, about 3 oder 8.
NTP is _not_ running, I'd like to solve this only by using the guest additions. After a few hours, I do not know anymore where to search for the mistake.

This morning, I made a mistake by editing the /etc/fstab on two of the systems, which had the effect, that / was mounted with the options nosuid, noexec and nodev. So I had to boot the two systems with a rescue cd to fix this error. Afterwards, the systems booted normally, but if I remember correctly, one of the two systems had problems with the system time.
Of course I have compared the settings of these two vms again and again (I used VBoxManage showvminfo), but I could not find anything of interest.

Anyway, here are the specs:
Host: Gentoo 2.6.36-gentoo-r5, virtualbox-bin-3.2.12-r1, virtualbox-modules-3.2.12
Guests: Gentoo 2.6.36-hardened-r9, virtualbox-guest-additions-3.2.12

The specs of two vms. "VM1" works fine, "VM2" does not get the correct time.

VM1

Code: Select all

Name:            VM1
Guest OS:        Gentoo
UUID:            38800e35-421c-4575-af40-2985b1f8285f
Config file:     /home/vms/VM1/VM1.xml
Hardware UUID:   38800e35-421c-4575-af40-2985b1f8285f
Memory size:     256MB
Page Fusion:     off
VRAM size:       8MB
HPET:            off
Number of CPUs:  1
Synthetic Cpu:   off
CPUID overrides: None
Boot menu mode:  message and menu
Boot Device (1): HardDisk
Boot Device (2): Not Assigned
Boot Device (3): Not Assigned
Boot Device (4): Not Assigned
ACPI:            on
IOAPIC:          off
PAE:             on
Time offset:     0 ms
RTC:             UTC
Hardw. virt.ext: on
Hardw. virt.ext exclusive: on
Nested Paging:   on
Large Pages:     off
VT-x VPID:       on
State:           running (since 2011-03-22T17:20:44.819000000)
Monitor count:   1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address: 
Teleporter Password: 
Storage Controller Name (0):            sata1
Storage Controller Type (0):            IntelAhci
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0):  30
Storage Controller Port Count (0):      2
sata1 (1, 0): /home/vms/VM1/VM1.vdi (UUID: eae123d2-bf88-41a1-a90b-abd8ddad945f)
NIC 1:           MAC: 08002762872E, Attachment: Bridged Interface 'eth0', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0
NIC 2:           disabled
NIC 3:           disabled
NIC 4:           disabled
NIC 5:           disabled
NIC 6:           disabled
NIC 7:           disabled
NIC 8:           disabled
Pointing Device: PS/2 Mouse
Keyboard Device: PS/2 Keyboard
UART 1:          disabled
UART 2:          disabled
Audio:           disabled
Clipboard Mode:  Bidirectional
Video mode:      720x400x0
VRDP:            enabled (Address 0.0.0.0, Ports 5031, MultiConn: off, ReuseSingleConn: off, Authentication type: null)
VRDP port:       5031
Video redirection: disabled
USB:             disabled

USB Device Filters:

<none>

Available remote USB devices:

<none>

Currently Attached USB Devices:

<none>

Shared folders:  <none>

VRDP Connection:    not active
Clients so far:     1
Last started:       2011/03/22 17:20:50 UTC
Last ended:         2011/03/22 17:58:01 UTC
Sent:               0 Bytes
Average speed:      0 B/s
Sent total:         0 Bytes
Received:           0 Bytes
Speed:              0 B/s
Received total:     0 Bytes

Guest:

OS type:                             Linux26
Additions active:                    yes
Configured memory balloon size:      0 MB

VM2

Code: Select all

Name:            VM2
Guest OS:        Gentoo
UUID:            7bce3bd8-992f-4030-b83c-1797eb720205
Config file:     /home/vms/VM2/VM2.xml
Hardware UUID:   7bce3bd8-992f-4030-b83c-1797eb720205
Memory size:     256MB
Page Fusion:     off
VRAM size:       8MB
HPET:            off
Number of CPUs:  1
Synthetic Cpu:   off
CPUID overrides: None
Boot menu mode:  message and menu
Boot Device (1): HardDisk
Boot Device (2): Not Assigned
Boot Device (3): Not Assigned
Boot Device (4): Not Assigned
ACPI:            on
IOAPIC:          off
PAE:             on
Time offset:     0 ms
RTC:             UTC
Hardw. virt.ext: on
Hardw. virt.ext exclusive: on
Nested Paging:   on
Large Pages:     off
VT-x VPID:       on
State:           running (since 2011-03-22T17:20:46.211000000)
Monitor count:   1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address: 
Teleporter Password: 
Storage Controller Name (0):            sata1
Storage Controller Type (0):            IntelAhci
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0):  30
Storage Controller Port Count (0):      2
sata1 (1, 0): /home/vms/VM2/VM2.vdi (UUID: f0fb1c14-52fe-4fb6-a929-a205747b6171)
NIC 1:           MAC: 08002734F692, Attachment: Bridged Interface 'eth0', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0
NIC 2:           disabled
NIC 3:           disabled
NIC 4:           disabled
NIC 5:           disabled
NIC 6:           disabled
NIC 7:           disabled
NIC 8:           disabled
Pointing Device: PS/2 Mouse
Keyboard Device: PS/2 Keyboard
UART 1:          disabled
UART 2:          disabled
Audio:           disabled
Clipboard Mode:  Bidirectional
Video mode:      720x400x0
VRDP:            enabled (Address 0.0.0.0, Ports 5032, MultiConn: off, ReuseSingleConn: off, Authentication type: null)
VRDP port:       5032
Video redirection: disabled
USB:             disabled

USB Device Filters:

<none>

Available remote USB devices:

<none>

Currently Attached USB Devices:

<none>

Shared folders:  <none>

VRDP Connection:    not active
Clients so far:     1
Last started:       2011/03/22 17:20:53 UTC
Last ended:         2011/03/22 17:57:57 UTC
Sent:               0 Bytes
Average speed:      0 B/s
Sent total:         0 Bytes
Received:           0 Bytes
Speed:              0 B/s
Received total:     0 Bytes

Guest:

OS type:                             Linux26
Additions active:                    yes
Configured memory balloon size:      0 MB

Here is the logfile of VM2: http://nopaste.info/afb7349150.html

Any help or at least helpful ideas and comments would be really appreciated.

Best regards,
Jimini

[Perryg]

You probably will get better help at Gentoo with this.
VirtualBox does not actually provide a Gentoo build only the source code which Gentoo builds from. (AFAIK)
Did you install this from the portage tree of Gentoo?

[Jimini]

Hey Perryg,
I installed it from the portage tree. It offers the sources and also the binaries, which I chose.

Best regards,
Jimini

[Perryg]

Still the binaries are Gentoo complied.
Gentoo 2.6.36-gentoo-r5, virtualbox-bin-3.2.12-r1, virtualbox-modules-3.2.12
Here are the binaries that VirtualBox.org provides for ver 3.2.12 VirtuaBox Downloads 3.2.12

[Jimini]

You were absolutely right. I could not find my mistake in any case, so I simply cloned the image of the working vm - now the time is finally correct.

Thank you for your comments!

Best regards,
Jimini

[Jimini]

Unfortunately, I have to re-open this thread. My VMs were incactive for a couple of days, until I started them today, their state was saved, so I simple "continued" them. I noticed, that on all four machines the time was drifting. 15 minutes, 3 seconds, 40 minutes, from machine to machine it almost seemed as the current time was chosen at random. Of course, the service "virtualbox-guest-additions" was running. Re-starting the service had no effect.
I found out, that executing "vboxguest-service --timesync-set-start" corrected the local time - but with every start of that program, another instance is running. What do you recommend? I thought about putting that program into crontab: starting it and killing it afterwards. But actually, this program only needs to be started immediately after the VM came up from the saved state.

Any ideas?

Best regards,
Jimini

[Perryg]

What causes this is saved state or pause. You can try to get around this as below. This changes the threshold to force a hard reset much faster. Usually about <= 30 Seconds on resume.

As su/sudo on guest to test
VBoxService --timesync-set-threshold 1000

Or run this on the host to make permanent
VBoxManage guestproperty set <VM name> "/VirtualBox/GuestAdd/VBoxService/--timesync-set-threshold" 1000

[Jimini]

Perryg, thank you for your quick response. I automatically stop the virtual machines when the host system is shut down - with "stop" I mean, that their state is saved. During boot-up, the virtual machines are continued.

This is what I executed:

Code: Select all

VBoxManage guestproperty set VM1 "/VirtualBox/GuestAdd/VBoxService/--timesync-set-threshold" 1000
VBoxManage guestproperty set VM2 "/VirtualBox/GuestAdd/VBoxService/--timesync-set-threshold" 1000
VBoxManage guestproperty set VM3 "/VirtualBox/GuestAdd/VBoxService/--timesync-set-threshold" 1000

But this had absolutely no effect - the clock is still drifting.

I thought about putting vboxguest-service --timesync-set-threshold 1000 into /etc/conf.d/local.start, I'll give this a try.

Best regards,
Jimini

[Perryg]

For any changes to take effect the guest will need to be (shutdown) not saved state.