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TODO

update grade not-z scripts to handle/be aware of winter terms
update system page for (new)www
scripts to write:
- user homedir backup pruning script
- deploy studentlistcreate as a cron job once again
- machine backup pruning script
- status page monthly cycle script
- revive gimmeh script, now that text access seems possible
manual pages to write:
- lab46 usage tutorial
  - include mercurial repository checkout info
  - include irc class chat tutorial
- data structures, sll/dll library functions as their own manual pages

URLs

Some links of interest:

Other Days

March 6th, 2018

Aside from an attempt at restarting my status-reporting habits in January of 2017, I totally neglected it for the remainder of the year.

So here we go, attempting another go. Will we be successful?

pods configured for better SSD operation

In other recent projects, I encountered some useful configuration options to improve performance, and avoid some anti-longevity side-effects of default settings.

I ended up taking a Debian USB installer, booting each pod in rescue mode, getting to a prompt, and running the following on EACH:

# umount /
# tune2fs -O ^has_journal /dev/sda1
# tune2fs -o discard /dev/sda1

Then on the master nodes, I enhanced both /etc/fstab and /etc/rc.local as follows:

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>         <dump>  <pass>
/dev/sda1       /               ext4    noatime,nodiratime,discard,commit=600,errors=remount-ro 0       1
tmpfs           /tmp            tmpfs   defaults,noatime,mode=1777 0 0
tmpfs           /var/log        tmpfs   defaults,noatime,mode=1777 0 0
tmpfs           /var/spool      tmpfs   defaults,noatime,mode=1777 0 0
tmpfs           /var/tmp        tmpfs   defaults,noatime,mode=1777 0 0

Note how I put the log files in RAM too (on the pods)… this should greatly reduce extraneous writes.

Then at the bottom of /etc/rc.local, I added:

#!/bin/sh -e
#
# rc.local
#
IPADDR=
while [ -z "${IPADDR}" ]; do
        IPADDR=`/usr/local/bin/iface | /bin/grep -v 'lo' | /usr/bin/head | /usr/bin/cut -d' ' -f2`
        sleep 1
done
/bin/hostname `/usr/bin/host ${IPADDR} | /usr/bin/cut -d' ' -f5 | /bin/sed s/\.$//`
/usr/bin/host ${IPADDR} | /usr/bin/cut -d' ' -f5 | /bin/sed s/\.$//  > /etc/hostname
echo "${IPADDR}    `cat /etc/hostname`"                              > /etc/hosts
echo "127.0.0.1    localhost"                                       >> /etc/hosts
echo "10.80.2.46   lab46.g7n.org lab46.corning-cc.edu"              >> /etc/hosts

echo deadline > /sys/block/sda/queue/scheduler
echo 1 > /sys/block/sda/queue/iosched/fifo_batch

exit 0

As the deadline scheduler has frequent mention of usage with SSDs.

Useful URLs:

lab46too SSD updates

With the pods having seen their SSD updates, I am looking to do the same for lab46too, testing to make sure the similar changes can be applied to that machine before rolling them over to lab46 proper.

I've updated the /etc/fstab and /etc/rc.local files accordingly on lab46, so those changes have been synced over to lab46too on a recent rsync run.

I had to remove the commit=600 from the /home partition. For some reason it didn't want to mount with that.

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