Add warning that the first start of VM pulls in updates

VirtualBox.md

@@ -1,22 +1,23 @@
-# Using sPHENIX and EIC-sPHENIX software with an Ubuntu Virtual Box
+# Using the sPHENIX software with an Ubuntu Virtual Box
 
-[Singularity container](./README.md) for sPHENIX and EIC-sPHENIX allow collaborators to run sPHENIX RCF/SDCC environment with the nightly builds on your local computers or on external high-performance computing clusters. It is optimized for offsite computing on Linux-based systems. 
+[Singularity container](./README.md) for sPHENIX allows collaborators to run the sPHENIX RCF/SDCC environment with the nightly builds on your local computers or on external high-performance computing clusters. It is optimized for offsite computing on Linux-based systems.
 
 On Windows or MacOS PC/laptop though, it could be tricky to run Singularity directly on the host system. Therefore, this page provide a solution to run sPHENIX Singularity container under an Linux Ubuntu [virtual box](https://www.virtualbox.org/wiki/Downloads), which can run well on Windows or MacOS. 
 
 1. Install VirtualBox on your host system: [Virtual Box](https://www.virtualbox.org/)
 
 2. Download [sPHENIX Ubuntu 18.04LTS Image](https://sphenix.sdcc.bnl.gov/WWW/user/phnxbld/sPHENIX/Singularity/Fun4AllSingularityDistribution.ova). The MD5SUM is `87a6464dbae831724bc9eb3b508f2646`.
 
-This image has CVMFS and Singularity3 preinstalled, enabling direct loading all sPHENIX builds via OpenScienceGrid network (i.e. Option-1 of [main documentation](/README.md)).   
+This image has CVMFS and Singularity3 preinstalled, enabling direct loading all sPHENIX builds via its OSG cvmfs volume network (i.e. Option-1 of [main documentation](/README.md)).
 
 3. Import the above image to your virtual box ([HowTs](https://www.google.com/search?q=Virtal+box+import+ova)). Please ensure you have internet connection before the next step (e.g. visit www.bnl.gov from inside the VirtualBox)
 
-Then you are good to go. Start the imported Virtual Box. The default user is `fun4all` with password of `fun4all`. It would be good practice to [change at least the password](https://www.google.com/search?q=ubuntu+howto+change+password) after first login. Following files are installed in the home folder: 
+Then you are good to go. Start the imported Virtual Box. **The Ubuntu VM is set to do unattended-upgrades. On the first start it will pull in and install a lot of package updates**. The default user is `fun4all` with password of `fun4all`. It would be good practice to [change at least the password](https://www.google.com/search?q=ubuntu+howto+change+password) after first login. Following files are installed in the home folder:
 * `~/singularity_shell.sh`: execute this script to get a bash shell with the Singularity container
 * `~/setup.sh`: source this macro from inside the Singularity container to use the lastest build 
 * `~/install/`: local build folder to be used for `$MYINSTALL` area, which is currently empty
 
+
 Start using it with an Ubuntu terminal:
 ```
 fun4all@Fun4AllSingularity:~$ ./singularity_shell.sh
@@ -31,7 +32,7 @@ Singularity> git clone https://github.com/sPHENIX-Collaboration/macros.git
 Cloning into 'macros'...
 ...
 
-Singularity> cd macros/macros/g4simulations/
+Singularity> cd macros/detectors/
 Singularity> root Fun4All_G4_sPHENIX.C
    ------------------------------------------------------------
   | Welcome to ROOT 6.16/00                  https://root.cern |