[Halla_running] Hall A counting house computers are back up

[Ole Hansen]

Hi everyone,

the Hall counting house computers are back online.

I used the opportunity to update all the machines with the latest
patches. That included upgrading form CentOS 7.4 to 7.5. The upgrade &
updates are completely transparent to the analysis and DAQ code; the
main change is a kernel update that required newer versions of the video
drivers.

Additionally - and this may not be totally transparent - I swapped the
host names of adaq2 and adaq3, as we had planned to do since getting the
adaq3 replacement earlier this year. Now the main DAQ machines, adaq1
and adaq2, have identical, nearly new hardware that is under full
warranty. adaq3 is an older, out-of-warranty machine. (We do have plenty
of spare parts for it.)

As before, please run the main DAQ on adaq1 and, if necessary, adaq2,
and use adaq3 for parasitic data taking, such as the parity test runs.

IMPORTANT: Since I only switched the host names, but not the disks, any
applications and data that previously were on a *local* adaq3 disk will
now be on adaq2 and vice versa. This might apply in particular to the
msql server databases. The DAQ experts should check and, if necessary,
swap those databases so that the respective DAQs will behave as before.

I did swap the ssh host keys of these two machines, so when connecting
to "adaq2" you'll be offered the same key as before, and similarly for
adaq3. There should be no host key warnings when ssh-ing into either system.

Finally, I installed the MATE desktop environment on all CentOS 7
machines as an alternative to the default Gnome3 desktop. While Gnome3
has fancy looks, it seems to become unresponsive at times with
long-running desktop sessions, as some of you discovered over the past
few months. The MATE desktop, which is based on the old and very stable
Gnome2 code, should be more resilient in this respect. I recommend we
run MATE for all sessions from now on, unless we discover some major
inconveniences with it.

You can choose which desktop to run when you enter the password at the
login screen: there is a small gear icon next to the "Next" button that
brings up a menu of available desktops. Choose "MATE" in this menu, then
log in. The setting will be memorized, so you only need to do this once.
I have already made this choice for the adaq account on adaq1 and adaq2
and for the a-onl account on aonl1-3 and adaqsc.

aonl4 is still running RHEL6 in case someone needs it for old code. If
you'd like me to upgrade it to CentOS 7, let me know.

If something doesn't work, you know where to complain.

Now hoping for beam ...

Ole

Am 11.09.18 um 15:02 schrieb Ole Hansen:
> Hello everyone,
> 
> in preparation for a possible power outage due to the approaching
> hurricane, we are planning to shut down the Hall A counting house
> computers tomorrow around noon. They will be booted back up once the
> hurricane has passed and power has been restored, if applicable, at the
> latest next Monday.
> 
> Please let me know if this causes anyone major problems; if so, we can
> discuss options.
> 
> Ole
>