Difference between revisions of "LabNet News"

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This page lists current and upcoming MUN LabNet projects that may affect users, such as
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Please check https://www.labnet.mun.ca/ for the latest info on Labnet issues that may affect users, such as
  
 
- scheduled maintenance
 
- scheduled maintenance
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- current system-wide issues
 
- current system-wide issues
 
Insert new reports below this line
 
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'''January 19, 2015'''
 
 
1)  Fixed problem in CS2718 Lab when one of the application servers lost the virtual disk containing the Ubuntu14x5 distribution.  The problem was initially remedied by pointing the clients to a different application server.  Later the virtual disk was restored.
 
 
2)  Started enabling Linux supprt for Engineering labs.  Created ssh keys and uploaded keys into our master database for computers in EN1038B.  Set up the rsyncing of the '''/images/linux''' images directory to all the Engineering application servers.
 
 
'''January 18,2015'''
 
 
1)  Set up two new computers in EN1049 to provide additional seating for Dr. Byrne's CS2718 course.  This endevour was fraught with many delays due to a lack of basic components.  An attempt should be made to have a few spare commonly used components readily available.
 
 
'''January 17, 2015'''
 
 
1)  After collecting changes to the Ubuntu14x5 image over the past week, a snapshot of this image was made and pushed up to pooky to be distributed to the various labnet application servers by the nightly software distribution cron job.
 
 
2)  The image was manually rsyned over to the departmental application servers, odie ane meatron and tests were made to ensure that the images worked in EN2036 and EN1049.
 
 
3)  It was noted that the computer, "chase" in EN2036 was inoperable due to a locked COW partition due to the COW partition having fill up.  Normal attempts to get rid of this COW partition were unsuccessful but a web page with the following URL:
 
 
https://www.globallinuxsecurity.pro/recovering-an-overflowed-lvm-volume-configured-with-virtualsize/
 
 
proved to be useful in remedying the problem.  Note this approach can be used whenever the '''lvs''' state of a volume look like '''-wi-Io----''' with a capital I as the fifth flag.  The capital i indicates that the logical volume is invalid.
 
 
'''January 16, 2015'''
 
 
1) Issue with stewart.lnesd.mun.ca contacting the Labnet configuration data base on arlene was resolved.
 
 
'''January 15, 2015'''
 
 
1) The C.S. genofflj printer has been temporarily replaced with an older printer.  A new printer will replace it in early February.
 
 
2) The colour printer in the C.S. general office is out for servicing.
 
 
3) Diskless on megatron.cs.mun.ca was upgraded to the test image so it would be in line with what is currently running in the other CS labs and in the Commons.
 
 
'''January 13, 2015'''
 
 
1)  CS faculty please note that speakers have been added to the A/V podium in EN1049.  (This was done in Dec., but not widely announced.)
 
 
2)  New wireless access points have been installed on the first floor of the Engineering building. This should greatly improve
 
service in the CS grad student lounge as well as EN1051 and EN1052.
 
 
3)  Network issues on login by the  CS secretarial staff this morning were found to due to  problems connecting with lysithea.pcgabs.mun.ca 's  /usr/local/pub share.
 
The reliance on this share, which has been an issue on past occasions,  has now been  disabled for all office staff machines.
 
The source of the problem was found to be the primary ldap server (scout.pcglabs.mun.ca)  for lysithea which had become unresponsive, The ldap service on scout.pcglabs.mun.ca was restarted. This resolved login issues being experienced across campus in addition to login and printing issues in the Commons. 
 
 
4)  At the request of IA's and Dr. Byrne, a new writable version of our iSCSI Ubuntu has been set up so that new software can be added.  The writable image is ssh'able on csgrad01.  The andrew, aaron, marian and pprice have been added to
 
to the sudoers config file and can do installs.  The computer will be available for updates until Friday at which point
 
a snapshot of the new image will be taken.  In the mean time feal free to add any relevent software that comes to mind.
 
 
'''January 12, 2015'''
 
 
1)  Fixed the problems in the automatic account generation code that have been plaguing the Commons.
 
 
2) Found a fix for the problem with Ubuntu14 login issues that failed due to "Failed session" error.
 
 
NOTE:  If people are having this problem logging in to Ubuntu then have the students use another session manager other than the default "Ubuntu" (unity) session manager.  The other two options are "Compiz" and "Metacity".  Basically these two look the same but "Compiz" is better able to take advantage of graphics card accellerators on supportted models (ie non Nvidia).  The button, a circular Ubuntu logo, that allows the user to switch session managers is located just above and to the right of the text box used to enter the user name.
 
 
'''January 10,11, 2015'''
 
 
1)  Set up '''sudoers''' managed file for Ubuntu computers 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 leaks etc.  Installed the software on the development image for 32/64 bit severs and for development,
 
diskless client computers.  On Sunday after checking that authentication is still working on development images, 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 (see log[1-6].vlg files).
 
 
3)  Switched the commons over to the new Ubuntu14x4 image and tested a number of clients.
 
 
4)  Added Ubuntu14x4 image to the IA's office PC's.
 
 
'''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.
 
 
3) Brought hope.engr.mun.ca back into sync in conjunction with the engineering department.
 
 
4) Found and adjusted a parameter on our master ldap server that prevented new slave ldap installations from completing to build.
 
 
'''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..
 

Latest revision as of 18:31, 19 April 2022

Please check https://www.labnet.mun.ca/ for the latest info on Labnet issues that may affect users, such as

- scheduled maintenance

- software upgrades

- equipment upgrades

- current system-wide issues