LabNet News

This page lists current and upcoming MUN LabNet projects that may affect users, such as

- scheduled maintenance

- software upgrades

- equipment upgrades

- current system-wide issues

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January 10,11, 2015

1) Set up sudoers managed file for Ubuntu comp[uters on Campus. This was done to allow members of CS2718 to be able to run certain commands requiring super user privilege in a safe and secure way. This will be used as a test case that can be used for future instances where elevated privleges are required.

2) Created a series of test cases for final the testing of the pam_labnet module and ran the code through the debugger to validate the logic. of each test case. Then ran the code through 'valgrind code checker to check for use of uninitialized valiables and memory letaks etc. Installed the software on the development image for 32/64 bit severs and for development, diskless client computers. On sunday after checking that athentication is stll workin in development, the test and production environments were built and installed. Notes: there may need to be some work done on some memory leaks on client side.

3) Switched the commons over to the new Ubuntu14x4 image and tested a number of clients.

January 9, 2015

1) Brought salsa.pcglabs.mun.ca the appserver for the Social work lab back up to date. It had been turned off since last August (2014) due to building renovations. Its new home is in CL3000. It was synced/upgraded to run the new server and diskless test images. The machine was booted onto the latest kernel that we have tested without any problems. It also has been reconfigured to use grub2 a newer version of the grand unified boot loader. The grub2 boot loader is now in use on all CS department machines and is being rolled out to other Labnet servers as they get upgraded.

2) Setup and tested client support in CS1019 for the new Ubuntu14x4 image. Discussed with Steve Johnson about the possibility of using Ubuntu as an alternative to Gentoo in the labs.

January 8, 2015

1) Tested the booting of the new Ubuntu iSCSI image in computer Labs EN1049 and EN-2036. Also added Ubuntu to the list of images that 'helppc' could boot and tested it to make sure that it works. Also distributed the new Ubuntu image to the application servers that boot the CS-1019 computer lab in preparation of rolling out Ubuntu in this computer Lab. Distributed the new image to the Commons as well.

2) Noticed that there were intermittent problems with booting the iSCSI images in EN-2036. When the operating system is selected from the boot menu the initrd loads but fails to open the iSCSI disk. It seems that the customization process runs without the iSCSI partition being properly mounted leaving configuration files in the mount point which in turn prevents the system from removing the mount point and thereby causing the image creation to abort. The solution right now is to manually remove the mount point (rm /tmp/<computer name>). If it reoccurs, a more permanent solution will be applied.

3) Talked to classroom support about the possibility of running Labnet on all the multimedia classrooms in the engineering building.

4) Started work on getting printing support working from the new Ubuntu image. This will probably involve creating a template file that will display a list of printers available to each client. The printer names associated with each client will be stored in the sys_config database.

January 7, 2015

1) Rolled out and announced initial version of this information page.

2) We experienced samba problems with access to home directories on lysithea.pcglabs.mun.ca. Decided to restart the samba service after consulting with the commons, which seems to have resolved the problem.

3) The EN1066 Mac lab has been re imaged as it was used for Mac OS X training during December. It is now running the latest version of OS X; Yosemite. It has been set up to use ldap authentication with our Labnet ldap servers so that users do not need to remember and use additional passwords beyond their MUN login one. The latest version of Xcode has been installed at the request of the mobile application course instructors. All students enrolled in the course have been added to the _developer group on each system in order to allow them to run Xcode.

4) Booted all the computers in CP2003 into Ubuntu in preparation for Dr. Byrne's course.

5) Updated the Ubuntu image and added several new packages needed by Dr. Byrne's course as well as some packages recommended by students and staff. Pushed the new image up to the master server for distribution this evening's rsync.

6) Set up the the classroom computers in EN1051, EN1052 and EN1054 so that they could avail of the new Ubuntu iSCSI boot image. To use simple reboot the computer and at the boot menu select the "Ubuntu Linux" menu item. When the login screen comes up login using you Labnet credentials.

7) Modified the configuration files for apache to include include files that will allow students with Dr. Byrnes course to be able to access course material from Dr. Byrne's GIT repository.

January 6, 2015

1) Set up the the classroom computers in EN1051, EN1052 and EN1054 so that they could avail of the new Ubuntu iSCSI boot image. To use, simply reboot the computer and at the boot menu select the "Ubuntu Linux" menu item. When the login screen comes up, login using your Labnet credentials.

2) Modified the configuration files for the apache server on stretch. The modifications direct apache to include files that will allow Dr. Byrne's students to be able to access course material from his GIT repository.

3) Sent off for a request for comments proposal to Hewlett Packard on a new printer standards initiative that will allow Labnet printing to be more functional with respect to printer job control and better cost recovery metrics.

4) CS genofflj printer has been temporarily removed for servicing.

Christmas Projects List 2014

During the Christmas break a number Labnet of projects were undertaken. Many of these projects could not be performed during the semester due to their intrusive nature. The following are brief descriptions of the projects arranged in more or less chronological order:

1) Configured the computers in the Computer Science labs and the CP2003 labs to boot the new iSCSI versions of the popular Ubuntu 14.0 distribution. This involved updating the image and pushing the image up to our master server and allowing it to update the various application servers. The virtual images were then created on the SSD disks of the application servers and the database configurations were updated appropriately. This will be used to support one of Dr. Byrne's courses.

2) Installed the server images for "isthmus" for the Math department. This was necessary because the libparted.so was upgraded and the buildserver application no longer builds the partition tables properly. It was necessary to manually build the partitions and then proceed with the install. This project is stalled due to problems loading the boot sector.

3) The size of our newer disk drives now exceeds the capabilities of the old "msdos" partition tables. The "GUID Partition Tables" or GPT will now be used in future server builds to support the larger disks. To boot from GPT partitioned disks the use of grub2 is under development. In addition UEFI boot support is under investigation. As servers are upgraded our server builds will be utilizing GPT and will be migrating to grub2 for booting. When better support for UEFI booting becomes more mature, support for UEFI will be incorporated. Currently there are a couple of servers that have been moved over to GPT partitions and the CS department is now booting with grub2.

4) One of our core Labnet daemons, "master_configd", responsible for managing the remote distribution of configuration services such as master file templates, certificates, printer account numbers etc. was becoming severely impacted by the shear number of requests that it received. To ameliorate this problem one of the modules was rewritten to perform work asynchronous and thereby reduce the strain on the daemon. The resulting code runs an order of magnitude faster and service requests are no longer creating backlogs.

5) Another service that was becoming bogged down was the user/system logging database that provides statistics on when and where students log into Labnet and what services they are requesting as well as the reboot logging of computers. An analysis of the data queries was performed to isolate the culprits. As it turned out the indices were not properly set up for several common queries and this turned out to be the culprit. The indexing was altered and now the queries work 2 orders of magnitude faster.

6) Performed network performance analysis on the Commons client/server communications. This was requested as a result of changes to the network infrastructure. Recommendations have been forwarded to the networking group within C&C as well as the Commons. It is hoped that this will be used to redesign the network layout to remove some of the bottlenecks.

7) The popular Ubuntu Linux 14.0 distribution was enabled for use in the Commons. This upgrade is similar to the upgrade to CP2003 and the Computer Science Department computer labs. This technology allows a client computer to mount a virtual disk over IP networks using the iSCSI protocol. The virtual disk is located on an application server that can remotely support an entire lab.

8) One of the final components of the "Account Archival Project" is the PAM Labnet module that reenables an account when a student returns to university. After the user's data has been collected and written to DVD's the home directory is removed and the LDAP entry is put in hibernation. When an archived Labnet user attempts to login, the login credential is restored and a new home directory is created. Wrote and debugged the PAM code that will be needed to reactivate user accounts after they have been archived.

9) To prepare for an up coming security, audit additions were made to the Labnet PAM module to allow for the seamless update of our remaining DES password hashes to the SHA1 hashes used by C&C. This will provide greater protection of our password hashes in the event that our password hashes are exposed. The newer SHA1 hashes are much more resiliant to brute force cracking than their DES counterparts..