Development for LHC@home

This is the same as v1.10 but testing using a cloned vdi file. This is needed with the new multiattach mode which does not allow using the exact same image in multiple versions. See this thread on the CMS forum for more details: https://lhcathomedev.cern.ch/lhcathome-dev/forum_thread.php?id=562

I got a task and all files from app version 0.84.
Did you restart the BOINC server?

<edit>
Sorry, my fault!
You published only a Windows version.
</edit>

Downloaded "ATLAS_vbox_0.84_image.vdi.gz" and "ATLAS_vbox_1.11_image.vdi.gz" from the dev server using wget,
extracted the vdis and manually attached them to the virtualbox media manager.

Good!
Each vdi has it's individual UUID and they can be attached side by side (that's what we have to ensure).

If 1.11_image is a clone from 0.84_image (or 1.10_image) I don't expect any trouble based on the UUID change.

First task is running with the new image-vdi after downloading the 1050MB gz-file.
The task starts OK.
The second task https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3094860 with the rather common error: Error while downloading

A log from another volunteer looks fine (even in connection with the older BOINC client 7.14.2 and vbox 5.2.44):
https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3094857

These are the most relevant lines:

2022-06-24 09:34:36 (9708): Detected: vboxwrapper 26204
.
.
.
2022-06-24 09:34:42 (9708): Adding virtual disk drive to VM. (ATLAS_vbox_1.11_image.vdi)
.
.
.
2022-06-24 09:34:56 (9708): Guest Log: BIOS: AHCI 0-P#0: PCHS=16383/16/63 LCHS=1024/255/63 0x0000000002800000 sectors

I got a task and all files from app version 0.84.
Did you restart the BOINC server?


Sorry, my fault!
You published only a Windows version.

I've added a linux version now (1.12). It uses the same vdi as 1.11 for Windows.

I've added a linux version now (1.12). It uses the same vdi as 1.11 for Windows.

Got 4 download errors in a row.
I suspect they are caused by the first computers getting the WU.
At least some of those I checked are misconfigured, e.g CVMFS not installed.
Could they be banished?



Finally I got 2 1-core tasks and 1 2-core task running.
All of them look fine (and nice to see the ATLAS Event Progress Monitoring still works):
https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3094876
https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3094872
https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3094869


Also checked the configuration files and the app_version entry in client_state.xml.
Everything looks fine.


The (Linux) vboxwrapper executable is still the non-stripped file.
Please run (on Linux) "strip vboxwrapper_26204_x86_64-pc-linux-gnu" and use the result of that command for the prod version (and the same file also for CMS/Theory).

Got 4 download errors in a row.

Stil today.
Some downloads ok, some others errors. On the same machine!!
I cannot understand why....

This happens when the first task of a WU fails or gets aborted, like here:
https://lhcathomedev.cern.ch/lhcathome-dev/workunit.php?wuid=2191425
https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3094629

All subsequent tasks then get an error due to a missing input file until the WU quota is reached and the WU stops.

As far as I understand this has something to do with the large input file size (on the prod system).
David Cameron had explained it somewhere but I can't find it ATM.


It's definitely not an issue caused by your local BOINC client.

The reason for the download errors is that tasks get cancelled upstream if they are not completed within a certain time. This removes the input files from the server but sometimes the cancellation of the WU does not work so they are stay in the queue. I'll try to make the cancellation work better or alternatively set a shorter deadline for the tasks sent here.

I'll try to make the cancellation work better or alternatively set a shorter deadline for the tasks sent here.

Thank you!!

@CP

would you mind testing your 20 core computer from LHC@home with short ATLAS tasks from here?
It's to find out whether the issues are caused by a Windows setting or something different.
Hence, the Windows configuration should not be changed.

If yes, please ask David Cameron to provide enough test tasks.

Thanks in advance

@CP

would you mind testing your 20 core computer from LHC@home with short ATLAS tasks from here?

Waking the monster . . .

@CP

would you mind testing your 20 core computer from LHC@home with short ATLAS tasks from here?

Waking the monster . . .

But so far only getting and running 1 task at a time (sometimes three)

Strange failing CVMFS and keep going in results:
2022-06-28 17:29:47 (6356): Guest Log: Checking CVMFS...
2022-06-28 17:29:48 (6356): Guest Log: Failed to check CVMFS, check output from cvmfs_config probe:
2022-06-28 17:29:48 (6356): Guest Log: Probing /cvmfs/atlas.cern.ch... Failed!
2022-06-28 17:29:48 (6356): Guest Log: Probing /cvmfs/atlas-condb.cern.ch... Failed!
2022-06-28 17:29:48 (6356): Guest Log: Probing /cvmfs/grid.cern.ch... Failed!
.
.
2022-06-28 17:43:49 (6356): Guest Log: Looking for outputfile output.1.6acf9c5c-3ff5-446e-bbd0-0f1b0df48f56_66324.pool.root
2022-06-28 17:43:49 (6356): Guest Log: HITS file was successfully produced

First task https://lhcathomedev.cern.ch/lhcathome-dev/result.php?resultid=3095893 where CVMFS is OK.

There are some differences reported at the computer details page.

Te CPU type (obviously).

https://lhcathomedev.cern.ch/lhcathome-dev/show_host_detail.php?hostid=4600 (running fine)
Microsoft Windows 10
Core x64 Edition, (10.00.19044.00)

BOINC Version 7.20.0



https://lhcathomedev.cern.ch/lhcathome-dev/show_host_detail.php?hostid=4547 (running ???)
Microsoft Windows 10
Professional x64 Edition, (10.00.19044.00)

BOINC Version 7.16.20




Both computers are running ATLAS as multicore using the same VirtualBox version, the same vboxwrapper and the same vdi file.


Be so kind as to check both computers against the settings given here (no change, just report different settings):
https://www.technewstoday.com/result-code-e_fail-0x80004005/

I don't have or had the E_FAIL (0x80004005) error here and also not with tasks from the production server.

I had CVMFS failures.

Btw: the 2 hosts you compared are different machines. A 4 threaded laptop and a 20 threaded desktop.

I don't have or had the E_FAIL (0x80004005) error here

I know.

the 2 hosts you compared are different machines

I know.



I just want to find out where the different errors come from, being it E_FAIL or CVMFS.
The E_FAIL page seems to be rather complete regarding the settings that are worth to be checked.
That's why I set a link.

Both computers are running ATLAS as multicore using the same VirtualBox version, the same vboxwrapper and the same vdi file.

Since this is the same on both computers we need to look for differences elsewhere.

The 2 .vbox-files with setings etc.
LT1 running a Theory task:
<?xml version="1.0"?>
<!--
** DO NOT EDIT THIS FILE.
** If you make changes to this file while any VirtualBox related application
** is running, your changes will be overwritten later, without taking effect.
** Use VBoxManage or the VirtualBox Manager GUI to make changes.
-->
<VirtualBox xmlns="http://www.virtualbox.org/" version="1.16-windows">
<Machine uuid="{6bc5d73a-bbaa-403e-973c-8d2f02aef630}" name="boinc_bc814ed1431c1e7e" OSType="Linux26_64" currentSnapshot="{efc15950-3348-48f4-b64f-d33513a53da6}" snapshotFolder="Snapshots" lastStateChange="2022-06-28T17:29:51Z">
<Description>Theory_2390-1126091-266_0</Description>
<MediaRegistry>
<HardDisks>
<HardDisk uuid="{08a2ffca-69a5-4a8f-ab20-c73b8e84b770}" location="D:/Boinc1/slots/1/vm_image.vdi" format="VDI" type="Normal">
<HardDisk uuid="{4808205f-a601-4dd5-87c0-378e8f37f4de}" location="Snapshots/{4808205f-a601-4dd5-87c0-378e8f37f4de}.vdi" format="VDI"/>
</HardDisk>
</HardDisks>
<DVDImages>
<Image uuid="{710b1c98-130a-487b-bcc3-db3e5325910e}" location="D:/Program Files/Oracle/VirtualBox/VBoxGuestAdditions.iso"/>
</DVDImages>
</MediaRegistry>
<Snapshot uuid="{efc15950-3348-48f4-b64f-d33513a53da6}" name="boinc_28176" timeStamp="2022-06-28T17:29:45Z" stateFile="Snapshots/2022-06-28T17-29-45-944331600Z.sav">
<Hardware>
<CPU>
<PAE enabled="true"/>
<LongMode enabled="true"/>
<X2APIC enabled="true"/>
<HardwareVirtExLargePages enabled="true"/>
</CPU>
<Memory RAMSize="730"/>
<Boot>
<Order position="1" device="HardDisk"/>
<Order position="2" device="DVD"/>
<Order position="3" device="None"/>
<Order position="4" device="None"/>
</Boot>
<VideoCapture screens="1" file="." fps="25"/>
<RemoteDisplay enabled="true">
<VRDEProperties>
<Property name="TCP/Ports" value="56155"/>
</VRDEProperties>
</RemoteDisplay>
<BIOS>
<IOAPIC enabled="true"/>
<SmbiosUuidLittleEndian enabled="true"/>
</BIOS>
<Network>
<Adapter slot="0" enabled="true" MACAddress="000000000000" type="82540EM">
<NAT>
<DNS use-proxy="true"/>
<Forwarding name="tcp_56154_80" proto="1" hostip="127.0.0.1" hostport="56154" guestport="80"/>
</NAT>
</Adapter>
</Network>
<AudioAdapter driver="DirectSound" enabledIn="false" enabledOut="false"/>
<SharedFolders>
<SharedFolder name="shared" hostPath="D:\Boinc1\slots\1\shared" writable="true" autoMount="false"/>
</SharedFolders>
<Clipboard/>
<IO>
<IoCache/>
<BandwidthGroups>
<BandwidthGroup name="boinc_bc814ed1431c1e7e_net" type="Network" maxBytesPerSec="1099511627776"/>
</BandwidthGroups>
</IO>
<GuestProperties>
<GuestProperty name="/VirtualBox/GuestAdd/CheckHostVersion" value="0" timestamp="1656404226752114800" flags=""/>
<GuestProperty name="/VirtualBox/GuestAdd/Revision" value="120293" timestamp="1656428190960907602" flags=""/>
<GuestProperty name="/VirtualBox/GuestAdd/Version" value="5.2.6" timestamp="1656428190960907600" flags=""/>
<GuestProperty name="/VirtualBox/GuestAdd/VersionExt" value="5.2.6" timestamp="1656428190960907601" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/MAC" value="0800274F4EE3" timestamp="1656428190983356600" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/Name" value="eth0" timestamp="1656428191004828600" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/Status" value="Up" timestamp="1656428190994091000" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/V4/Broadcast" value="10.0.2.255" timestamp="1656428190972620401" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/V4/IP" value="10.0.2.15" timestamp="1656428190972620400" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/V4/Netmask" value="255.255.255.0" timestamp="1656428190972620402" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/Count" value="1" timestamp="1656437384509573300" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/LoggedInUsers" value="0" timestamp="1656428190960907603" flags="TRANSIENT, TRANSRESET"/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/NoLoggedInUsers" value="true" timestamp="1656428190960907604" flags="TRANSIENT, TRANSRESET"/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/Product" value="Linux" timestamp="1656428190917002900" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/Release" value="4.14.76-13.cernvm.x86_64" timestamp="1656428190917002901" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/Version" value="#1 SMP Tue Oct 16 18:26:15 CEST 2018" timestamp="1656428190927724200" flags=""/>
<GuestProperty name="/VirtualBox/HostInfo/GUI/LanguageID" value="C" timestamp="1656431529517903300" flags="RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxRev" value="150636" timestamp="1656428190703242802" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxVer" value="6.1.34" timestamp="1656428190703242800" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxVerExt" value="6.1.34" timestamp="1656428190703242801" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/VMInfo/ResumeCounter" value="272" timestamp="1656437098354241900" flags="TRANSIENT, RDONLYGUEST"/>
</GuestProperties>
</Hardware>
<StorageControllers>
<StorageController name="Hard Disk Controller" type="PIIX4" PortCount="2" useHostIOCache="true" Bootable="true">
<AttachedDevice type="HardDisk" hotpluggable="false" port="0" device="0">
<Image uuid="{08a2ffca-69a5-4a8f-ab20-c73b8e84b770}"/>
</AttachedDevice>
<AttachedDevice passthrough="false" type="DVD" hotpluggable="false" port="1" device="0">
<Image uuid="{710b1c98-130a-487b-bcc3-db3e5325910e}"/>
</AttachedDevice>
</StorageController>
</StorageControllers>
</Snapshot>
<Hardware>
<CPU>
<PAE enabled="true"/>
<LongMode enabled="true"/>
<X2APIC enabled="true"/>
<HardwareVirtExLargePages enabled="true"/>
</CPU>
<Memory RAMSize="730"/>
<Boot>
<Order position="1" device="HardDisk"/>
<Order position="2" device="DVD"/>
<Order position="3" device="None"/>
<Order position="4" device="None"/>
</Boot>
<VideoCapture screens="1" file="." fps="25"/>
<RemoteDisplay enabled="true">
<VRDEProperties>
<Property name="TCP/Ports" value="56155"/>
</VRDEProperties>
</RemoteDisplay>
<BIOS>
<IOAPIC enabled="true"/>
<SmbiosUuidLittleEndian enabled="true"/>
</BIOS>
<Network>
<Adapter slot="0" enabled="true" MACAddress="000000000000" type="82540EM">
<NAT>
<DNS use-proxy="true"/>
<Forwarding name="tcp_56154_80" proto="1" hostip="127.0.0.1" hostport="56154" guestport="80"/>
</NAT>
</Adapter>
</Network>
<AudioAdapter driver="DirectSound" enabledIn="false" enabledOut="false"/>
<SharedFolders>
<SharedFolder name="shared" hostPath="D:\Boinc1\slots\1\shared" writable="true" autoMount="false"/>
</SharedFolders>
<Clipboard/>
<IO>
<IoCache/>
<BandwidthGroups>
<BandwidthGroup name="boinc_bc814ed1431c1e7e_net" type="Network" maxBytesPerSec="1099511627776"/>
</BandwidthGroups>
</IO>
<GuestProperties>
<GuestProperty name="/VirtualBox/GuestAdd/CheckHostVersion" value="0" timestamp="1656404226752114800" flags=""/>
<GuestProperty name="/VirtualBox/GuestAdd/Revision" value="120293" timestamp="1656428190960907602" flags=""/>
<GuestProperty name="/VirtualBox/GuestAdd/Version" value="5.2.6" timestamp="1656428190960907600" flags=""/>
<GuestProperty name="/VirtualBox/GuestAdd/VersionExt" value="5.2.6" timestamp="1656428190960907601" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/MAC" value="0800274F4EE3" timestamp="1656428190983356600" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/Name" value="eth0" timestamp="1656428191004828600" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/Status" value="Up" timestamp="1656428190994091000" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/V4/Broadcast" value="10.0.2.255" timestamp="1656428190972620401" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/V4/IP" value="10.0.2.15" timestamp="1656428190972620400" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/0/V4/Netmask" value="255.255.255.0" timestamp="1656428190972620402" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/Net/Count" value="1" timestamp="1656437384509573300" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/LoggedInUsers" value="0" timestamp="1656428190960907603" flags="TRANSIENT, TRANSRESET"/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/NoLoggedInUsers" value="true" timestamp="1656428190960907604" flags="TRANSIENT, TRANSRESET"/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/Product" value="Linux" timestamp="1656428190917002900" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/Release" value="4.14.76-13.cernvm.x86_64" timestamp="1656428190917002901" flags=""/>
<GuestProperty name="/VirtualBox/GuestInfo/OS/Version" value="#1 SMP Tue Oct 16 18:26:15 CEST 2018" timestamp="1656428190927724200" flags=""/>
<GuestProperty name="/VirtualBox/HostInfo/GUI/LanguageID" value="C" timestamp="1656431529517903300" flags="RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxRev" value="150636" timestamp="1656428190703242802" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxVer" value="6.1.34" timestamp="1656428190703242800" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxVerExt" value="6.1.34" timestamp="1656428190703242801" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/VMInfo/ResumeCounter" value="272" timestamp="1656437098354241900" flags="TRANSIENT, RDONLYGUEST"/>
</GuestProperties>
</Hardware>
<StorageControllers>
<StorageController name="Hard Disk Controller" type="PIIX4" PortCount="2" useHostIOCache="true" Bootable="true">
<AttachedDevice type="HardDisk" hotpluggable="false" port="0" device="0">
<Image uuid="{4808205f-a601-4dd5-87c0-378e8f37f4de}"/>
</AttachedDevice>
<AttachedDevice passthrough="false" type="DVD" hotpluggable="false" port="1" device="0">
<Image uuid="{710b1c98-130a-487b-bcc3-db3e5325910e}"/>
</AttachedDevice>
</StorageController>
</StorageControllers>
</Machine>
</VirtualBox>

======================================================
i9-Boinc1 running ATLAS:
<?xml version="1.0"?>
<!--
** DO NOT EDIT THIS FILE.
** If you make changes to this file while any VirtualBox related application
** is running, your changes will be overwritten later, without taking effect.
** Use VBoxManage or the VirtualBox Manager GUI to make changes.
-->
<VirtualBox xmlns="http://www.virtualbox.org/" version="1.16-windows">
<Machine uuid="{7751f335-0b22-4802-9bdb-d86ed0a68c1b}" name="boinc_3774a2be3a81480d" OSType="Linux26_64" snapshotFolder="Snapshots" lastStateChange="2022-06-28T17:24:20Z">
<Description>FyJNDmt6TQ1n7Olcko1bjSoqABFKDmABFKDmKFbSDmS6GKDmHqigTo_0</Description>
<MediaRegistry>
<HardDisks>
<HardDisk uuid="{47a508a4-96ae-4cca-846d-dd8914041591}" location="E:/Boinc1/projects/lhcathomedev.cern.ch_lhcathome-dev/ATLAS_vbox_1.11_image.vdi" format="VDI" type="MultiAttach">
<HardDisk uuid="{94665635-8c85-4bf3-b051-3e7b516c14b0}" location="Snapshots/{94665635-8c85-4bf3-b051-3e7b516c14b0}.vdi" format="VDI"/>
</HardDisk>
</HardDisks>
<DVDImages>
<Image uuid="{483feebb-9f42-437a-a5ff-96b530116e44}" location="C:/Program Files/Oracle/VirtualBox/VBoxGuestAdditions.iso"/>
</DVDImages>
</MediaRegistry>
<Hardware>
<CPU count="4">
<PAE enabled="true"/>
<LongMode enabled="true"/>
<X2APIC enabled="true"/>
<HardwareVirtExLargePages enabled="true"/>
</CPU>
<Memory RAMSize="6600"/>
<Boot>
<Order position="1" device="HardDisk"/>
<Order position="2" device="DVD"/>
<Order position="3" device="None"/>
<Order position="4" device="None"/>
</Boot>
<Display VRAMSize="16"/>
<VideoCapture file="." fps="25"/>
<RemoteDisplay enabled="true">
<VRDEProperties>
<Property name="TCP/Ports" value="52938"/>
</VRDEProperties>
</RemoteDisplay>
<BIOS>
<IOAPIC enabled="true"/>
<SmbiosUuidLittleEndian enabled="true"/>
</BIOS>
<Network>
<Adapter slot="0" enabled="true" MACAddress="000000000000" type="82540EM">
<NAT>
<DNS use-proxy="true"/>
<Forwarding name="tcp_52937_80" proto="1" hostip="127.0.0.1" hostport="52937" guestport="80"/>
</NAT>
</Adapter>
</Network>
<AudioAdapter driver="DirectSound" enabledIn="false" enabledOut="false"/>
<SharedFolders>
<SharedFolder name="shared" hostPath="E:\Boinc1\slots\2\shared" writable="true" autoMount="false"/>
</SharedFolders>
<Clipboard/>
<IO>
<IoCache/>
<BandwidthGroups>
<BandwidthGroup name="boinc_3774a2be3a81480d_net" type="Network" maxBytesPerSec="1099511627776"/>
</BandwidthGroups>
</IO>
<GuestProperties>
<GuestProperty name="/VirtualBox/HostInfo/GUI/LanguageID" value="nl_NL" timestamp="1656437060217477100" flags="RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxRev" value="150636" timestamp="1656437060209697202" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxVer" value="6.1.34" timestamp="1656437060209697200" flags="TRANSIENT, RDONLYGUEST"/>
<GuestProperty name="/VirtualBox/HostInfo/VBoxVerExt" value="6.1.34" timestamp="1656437060209697201" flags="TRANSIENT, RDONLYGUEST"/>
</GuestProperties>
</Hardware>
<StorageControllers>
<StorageController name="Hard Disk Controller" type="AHCI" PortCount="3" useHostIOCache="false" Bootable="true" IDE0MasterEmulationPort="0" IDE0SlaveEmulationPort="1" IDE1MasterEmulationPort="2" IDE1SlaveEmulationPort="3">
<AttachedDevice type="HardDisk" hotpluggable="false" port="0" device="0">
<Image uuid="{94665635-8c85-4bf3-b051-3e7b516c14b0}"/>
</AttachedDevice>
<AttachedDevice passthrough="false" type="DVD" hotpluggable="false" port="1" device="0">
<Image uuid="{483feebb-9f42-437a-a5ff-96b530116e44}"/>
</AttachedDevice>
</StorageController>
</StorageControllers>
</Machine>
</VirtualBox>

LT1 is using the traditional method:
<HardDisk uuid="{08a2ffca-69a5-4a8f-ab20-c73b8e84b770}" location="D:/Boinc1/slots/1/vm_image.vdi" format="VDI" type="Normal">

Is it a task from prod?



i9-Boinc1 is using the new method:
<HardDisk uuid="{47a508a4-96ae-4cca-846d-dd8914041591}" location="E:/Boinc1/projects/lhcathomedev.cern.ch_lhcathome-dev/ATLAS_vbox_1.11_image.vdi" format="VDI" type="MultiAttach">
<HardDisk uuid="{94665635-8c85-4bf3-b051-3e7b516c14b0}" location="Snapshots/{94665635-8c85-4bf3-b051-3e7b516c14b0}.vdi" format="VDI"/>

The "snapshot" isn't a real snapshot.
Instead it's the differencing image.


Both VM definitions seem to be OK.