Date: Tuesday, October 20, 2026 (06:00-12:00)

Who is affected:
All users of the CS department storage or computing facilities.

What is happening:
We are upgrading the operating system on the CS storage cluster, which
requires the components of the system to be rebooted. This upgrade is
expected to be mostly non-disruptive, especially because it coincides with
the power maintenance, when ionic and neuronic cluster systems will be
offline anyway, but sporadic moments of interruption may be noticeable at
times particularly for CIFS/SMB users.

All services that depend upon access to storage share the same minor risk
of performance hiccups for some periods during this window, web content,
home directories, CIFS/SMB, etc. We do not anticipate any extended outage
of the storage service; however, some CIFS/SMB connections may need to be
reestablished.

Why is it happening:
This is a regular maintenance upgrade to install a newer version of the
storage system software.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Monday, September 28, 2026 (08:00-10:00)

Who is affected:
All users of the CS Department Beowulf high performance computing clusters,
known as ionic and neuronic.

All users of the CS Staff-managed public login systems, including the
cycles, courselab, and armlab systems.

What is happening:
CS Staff will apply emergency RHEL 9 security updates to the Ionic and
Neuronic clusters, as well as the Cycles, Courselab, and Armlab systems, to
address recently identified security vulnerabilities.

The Neuronic login node, Cycles, Courselab, and Armlab systems will be
updated and rebooted during the scheduled maintenance window. Users may
experience temporary service interruptions and will be unable to access the
affected systems while they are being rebooted.

Ionic and Neuronic compute nodes will be updated and rebooted on a rolling
basis as they become available, either after running jobs have completed or
when the nodes have been drained. This approach will allow us to perform
the necessary security updates while minimizing disruption to running
jobs.

Please note that we expect to complete the updates to the login systems
earlier than the scheduled maintenance window, but the extended time frame
allows for any unexpected issues that may arise.

Why is it happening:
This emergency maintenance is necessary to address security vulnerabilities
and protect the security and integrity of our computing infrastructure.

Applying these security updates promptly helps safeguard user data, reduce
the risk of unauthorized access, and maintain a secure and reliable
computing environment for all users.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Tuesday, October 20, 2026 (06:00-18:00)

Who is affected:
ALL users of CS Department (or University) cluster computing systems
AND
ALL users of research rack space at the HPCRC (151 Forrestal Road)

What is happening:
On October 20, 2026, all “B”-side power at the HPCRC will be turned off and
unavailable for the full business day while preventative major maintenance
is performed on the building’s power systems. “B”-side power accounts for
half the power to the building, and ALL of the power to some racks occupied
by the Computer Science Department.

Other than the ionic and neuronic clusters, most research racks in the CS
portion of the HPCRC use “A”-side power. Nevertheless, it would be prudent
to anticipate that research racks may lose power at 07:00 and not regain
power before 15:00. It is recommended that researchers arrange to power off
their equipment prior to the 07:00 start time and be prepared to check its
health and restore services after the 15:00 end. CS Staff is announcing a
wider 12-hour window to allow for this time to orderly shut down clusters,
and to power back on after the work.

ALL ionic and neuronic cluster resources will be offline and unavailable.
ALL courselab and armlab systems will be offline and unavailable.
The “cycles” systems will be rebooted at the start of the window, but are
anticipated to be available.
All other central CS services (e.g. email, web service, storage) are
anticipated to remain available.

OIT’s announcement of this maintenance can be found here:
oit.princeton.edu/events/hpcrc-planned-downtime-maintenance

Why is it happening:
The power equipment at the HPCRC is overdue for major maintenance to reduce
the risk of unplanned failures and outages. This maintenance window, like
the earlier outage on June 9, allows for this maintenance to be performed
safely.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Tuesday, September 1, 2026 (06:00-12:00)

Who is affected:
All users of the CS Department Beowulf high performance computing clusters,
known as ionic and neuronic.

All users of the CS Staff-managed public login systems, including the cycles, courselab, and armlab systems.

What is happening:
CS Staff will upgrade the Ionic and Neuronic clusters, as well as the Cycles, Courselab, and Armlab systems, to the latest Red Hat 9 distribution.

Please note that we expect to finish the upgrades earlier than this window,
but the wide time frame acknowledges the uncertainties involved.

Why is it happening:
This is part of our regular maintenance to keep systems secure and
reliable. As security threats continue to grow, we’ll be updating our
systems more frequently to protect personal data and close software
vulnerabilities.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Wednesday, August 19, 2026 (07:00-09:00)

Who is affected:
All CS department services will experience short periods of disruption
within the maintenance window.

What is happening:
We will be upgrading network switches located at the Forrestal Campus Data
Center. The plan is to perform the most disruptive outages during the start
of the scheduled downtime, followed by smaller isolated outages near the
end of the scheduled downtime.

Why is it happening:
The firmware on these switches is in need of an upgrade in order to patch
for security issues, bugs, to standardize firmware versions across our
equipment, and to implement new features on our network switches for future
projects.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Wednesday, July 29, 2026 (08:00-10:00)

Who is affected:
All CS department services will experience short periods of disruption
within the maintenance window – with the exception of WiFi.

What is happening:
We will be upgrading the firmware on our core switch/router in room 218 of
the CS building and all network switches located at the Forrestal Campus
Data Center. The plan is to perform the most disruptive outages first,
followed by smaller isolated outages.

Why is it happening:
The firmware on these switches is in need of an upgrade in order to patch
for security issues, bugs, to standardize firmware versions across our
equipment, and to implement new features on our network switches for future
projects.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Tuesday, July 14, 2026 (06:00-14:00)

Who is affected:
All users of the CS Department Beowulf high performance computing clusters,
known as ionic and neuronic.

All users of the CS Staff-managed public login systems, including the
cycles, courselab, and armlab systems.

What is happening:
CS Staff will upgrade the Ionic and Neuronic clusters, as well as the
Cycles, Courselab, and Armlab systems, to the latest Red Hat 9
distribution.

In addition, the cluster management and job scheduling system, Slurm, along
with its database, will also be upgraded. No data loss is anticipated.

Why is it happening:
This is part of the routine maintenance and will bring newer versions of
installed tools and software.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Wednesday, July 1st, 2026 (09:00-10:30)

Who is affected:
Any equipment connected to the network in room 002 of the Computer Science
building. Please note, this will not impact wireless connectivity, phones,
printers, etc. This event will be isolated to equipment housed in 002 only.

What is happening:
We will be upgrading the firmware on our network switches in room 002. This
action will result in brief network outages for any equipment in this room.
This upgrade will be conducted one switch at a time to both reduce risk and
only cause brief isolated outages.

Why is it happening:
The firmware on these switches is in need of an upgrade in order to patch
for security issues, bugs, and to implement new features on our network
switches for future projects.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Good morning.

This is a reminder that the below scheduled downtime takes place tomorrow, June 9.

Cheers,
Chris Miller
Senior Manager of Infrastructure Operations
Computer Science Department

—– Original Message —–
From: “csstaff” <csstaff@cs.princeton.edu>
To: “downtime” <downtime@lists.cs.princeton.edu>
Sent: Monday, April 6, 2026 1:22:02 PM
Subject: [downtime] HPCRC Data Center Downtime, Tuesday, June 9, 2026, 06:00-18:00

Date: Tuesday, June 9, 2026 (06:00-18:00)

Who is affected:
ALL users of CS Department (or University) cluster computing systems
AND
ALL users of research rack space at the HPCRC (151 Forrestal Road)

What is happening:
On June 9, 2026, all “A”-side power at the HPCRC will be turned off and
unavailable for the full business day while preventative major maintenance
is performed on the building’s power systems. “A”-side power accounts for
half the power to the building, and ALL of the power to most racks occupied
by the Computer Science Department.

ALL researchers with equipment in HPCRC racks should anticipate that they
will lose power at 07:00 and not regain power before 15:00. It is
recommended that researchers arrange to power off their equipment prior to
the 07:00 start time and be prepared to check its health and restore
services after the 15:00 end. CS Staff is announcing a wider 12-hour window
to allow for this time to orderly shut down clusters, and to power back on
after the work.

ALL ionic and neuronic cluster resources will be offline and unavailable.
ALL courselab and armlab systems will be offline and unavailable.
The “cycles” systems will be rebooted at the start of the window, but are
anticipated to be available.
All other central CS services (e.g. email, web service, storage) are
anticipated to remain available.

OIT’s announcement of this maintenance can be found here:
oit.princeton.edu/events/hpcrc-planned-downtime-maintenance

Why is it happening:
The power equipment at the HPCRC is overdue for major maintenance to reduce
the risk of unplanned failures and outages. This maintenance window, and a
related upcoming outage on October 20, will allow for this maintenance to
be performed safely.

The October 20 outage will be announced separately later in the Summer and
will be essentially identical to this one, but affecting the “B”-side
power.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff

Date: Tuesday, June 2nd, 2026 (09:00-10:30)

Who is affected:
Anything physically connected to the CS building network in the offices and
open areas. Please note, this will not impact wireless connectivity or any
of the equipment in room 002.

What is happening:
We will be upgrading the firmware on our network switches in room 218. This
action will result in a brief network outage of approximately 3 minutes in
each respective location. This upgrade will be conducted one switch at a
time to both reduce risk and only cause brief isolated outages.

Why is it happening:
The firmware on these switches is in need of an upgrade in order to patch
for security issues, bugs, and to implement new features on our network
switches for future projects.

We will post updates to the status page: www.csstaff.org
as necessary.

If this downtime will cause you undue hardship, please contact
csstaff@cs.princeton.edu immediately, so we can discuss options to reduce
any negative impact. Your patience is appreciated.

Sincerely,
CS Staff