Reboots Didn’t Happen Tonight – Maybe Tomorrow

      It was more important that I get the guests and my workstation updated as they are open to public attack.  The host machines really don’t provide any services so are less exposed.  Upgrades were slow in part because the DoS attack impeded the ability to resolve ubuntu’s server names.  It may happen tomorrow if things go well.

DynDNS is currently undergoing a massive DDOS attack

     DynDNS is currently undergoing a massive DDOS attack.  Sites that outsource their DNS to DynDNS are currently difficult to reach.

     I have found that Google’s name servers tend to cache data forever and so even when the primary name server is down, Google’s name servers will usually return good data.

     I had quite a bit of mail backing up in the mail queues of mx1 and mx2 owing to the inability to resolve DNS of destination sites.  I have added a Google public name server to these machines and re-queued the mail and much of it is making it out now.

Reboots – Security Upgrade

     I had to reboot all the shell servers and the web server to install new kernels to fix a security problem.  I will be rebooting the physical host machines around 9pm tomorrow.  This will momentarily interrupt all services but is necessary to eliminate a security exploit.


Brief Maintenance Tonight

     There will be a period of roughly 3-10 seconds where you will not have access to your home directories. This will cause whatever is trying to access these files to hang for this period.

     This is necessary to replace a defective Ethernet cable that ties the NFS server hosting your /home directories to the switch.  The existing cable sometimes does not make connection if you wiggle it.  This is not a good thing for such a critical server and so needs to be addressed sooner rather than later.

     I will plug the new cable into another port in the Ethernet switch, route it to the server, then unplug the existing cable and plug the new one in.  That will probably take a second but since it’s a different port the MAC address on the switch end changes and it will take the computer and the switch a few seconds to figure that out via ARP protocol.

System Maintenance Completed – Finally

     System maintenance did not go smoothly tonight.  It went smooth on two of three physical host machines, the third, which happens to host the /home directories, would come up then halt with the supposed detection of a power surge.

     Since this behavior did not start until after software upgrades, I assumed it had something to do with the upgrade, backed it out and re-applied, then it came up and ran.  This was made difficult by the fact that the machine usually would not run long enough to do anything before it died again so it required many attempts.  Grub is also buggy on these machines and does not display the boot menu so booting an old kernel to fix it was not an option.

     Compounding the problem, one of the ethernet cables is flakey and I was out of spares so will have to get some replacements.  I got it to work and I am sure it will work until physically disturbed again but connectors you have to wiggle to get to work are no good.

Server Reboots

     I will be rebooting servers starting at about 12:15AM October 11th (about 1/2 hour from now) in order to make updates effective.  This will interrupt all non-duplicated services, services which are duplicated, external mx mail receiving servers, DNS servers, radius authentication, all will experience an interruption in one of the duplicated members.  Services which are not replicated, shell servers, web server, ftp server, will experience an outage lasting approximately ten minutes.  This is necessary in order to keep software current.


Mint 18 X2Go

     I upgraded the Mint server to Mint 18.  This broke x2go in a small way.  The x2go xserver has version 1.2 of xrandr, but Mint 18 requires at least version 1.3, so the screen sizing fails.

     However, the xrandr command is version 1.5, so when you first connect with x2go and get a small 800×600 pixel screen open a terminal and type:

     xrandr -s (width)x(height) in pixels, for example, my screen is 1680×1050, so to get the display to use the whole screen I type “xrandr -s 1680×1050”.

     This is only necessary temporarily until I can figure out how to resolve an issue with xagent version and GPG keys.

OwnCloud / User Meeting


     The owncloud client is installed on  You can share your file space here with your other devices by using the owncloud client on centos7.  Because our file space is shared across all shell servers it will work to have it synchronized with centos7 even if you don’t regularly use that server.

     There is a good owncloud write-up in the Linux Journal.

     User Meeting:

     There have been enough responses indicating a willingness and desire to attend to warrant a meeting on October 29th so I have reserved the banquet room at Spiros on 185th and Aurora.

     The meeting will be held somewhat later this time because of the times the room was available.  It will be held from 4pm-7pm.

     I have had some feedback indicating a desire for a more structured meeting in the past but when I’ve done this in the past nobody showed up.  However, if you would like me to talk on a particular topic please e-mail me as soon as possible.

     Even though we’ve had enough RSVP’s to warrant a meeting, I still would like you to RSVP if you are going to attend.  This way I can give Spiros a more accurate number so they know how many seating positions to setup with silverware and what not.