April 2008 Archives

As described in my earlier posting, I will be shutting down all servers before the power outages tomorrow morning and Sunday evening. I will also be scheduling shutdowns of the stand-alone desktop linux workstations which we manage, including the grad-student/post-doc Dell GX 270s. I strongly recommend that you shutdown your Windows or OS X workstation before the power outages.

I am going to disable all backups but mathserv tonight since we won't have time to backup all systems.

The following summary of recent notices was emailed to all department members on Wednesday, April 30th.

Power, Server & Network Outages this Week
Workstations and servers will be down or unavailable to some degree Thursday morning, Friday afternoon, Sunday morning and Sunday evening to Monday morning (RHPCS, UTS and FS have all scheduled disruptive work for the end of the exam period, it appears).
http://www.math.mcmaster.ca/blogs/archives/computing_news/2008/04/power-server-ne.html

Spam & Backscatter
The backscatter filtering announced two weeks ago has been turned off for a week now due to problems with false positives. We will be making changes to the spam filtering mechanism in the next week or so which will result in your spam and bounce folders being renamed and backscatter filtering working again.
http://www.math.mcmaster.ca/blogs/archives/computing_news/2008/04/spam-backscatte.html

HH-401 Colour Printer - Now in Colour! (again)
It ends up we had spare colour toner for the Lexmark C750 in HH-401, so we have a departmental colour printer again until it runs out.
http://www.math.mcmaster.ca/blogs/archives/computing_news/2008/04/hh401-colour-pr.html

Also of interest to a number of department members ...

Workstation Upgrades
http://www.math.mcmaster.ca/blogs/archives/computing_news/2008/04/workstation-upg.html

Workstations Being Renamed
http://www.math.mcmaster.ca/blogs/archives/computing_news/2008/04/workstations-be.html

The backscatter filtering announced two weeks ago has been turned off for a week now due to problems with false positives. We will be making changes to the spam filtering mechanism in the next week or so which will result in your spam and bounce folders being renamed and backscatter filtering working again.

Workstations and servers will be down or unavailable to some degree four times in the next week:

• Thursday from 5:00 am to 8:30 am due to a power shutdown by Facility Services
  
• Friday from 3:00 pm to 5:00 pm while I do fail-over testing
  
• Sunday morning from 7:00 am to 8:00 am due to network work by UTS
  
• Sunday evening / Monday morning from 6:00 pm to 8:30 am due to a power shutdown by Facility Services

UTS and FS, like RHPCS, have scheduled disruptive work for the end of the exam period, it appears.

UTS has announced that network access to and from campus will be down for ca. ten minutes on Sunday, May 4th from 7:00 am to 8:00 am. MacConnect wireless will be down from 8:00 am to 11:00 am.

A reminder that the power in HH will be out on Sunday from 6:00 pm until 3:00 am. All servers will be down for that period and email and the web sites will be inaccessible. The linux workstations will also be down. I will power the servers off at 5:00 pm on Sunday and bring them back up at 8:30 am on Monday.

Facilities Services announced Monday that power to HH will be out from 5:00 am to 8:00 am this Thursday. We don't have the battery capacity to keep the servers running for three hours, so I will schedule a 4:00 am shutdown of all servers; I will restart them at ca. 8:30 am.

I'm going to be renaming each of the standard linux workstations used by grad students and post docs in the next week or so. The current names are msx, where x is a prime number: ms002, ms003 ... ms587. These names are short and slightly cute, but most people don't know what their systems are called when asked by the sysadmins; everybody seems to know the location of their desks, however. The new names will be based on building, room and desk number, for example ms-hh-303-04.

I am going to be upgrading the standard linux workstations from Mandriva 2006.0 to Mandriva 2008.0 in early May; you'll be able to tell that your system has been upgraded by the change to the login screen. The new version is very much like the current one, only with updated applications, some interface simplifications, and a general increased shininess. Email sysadmin@math.mcmaster.ca if you discover anything to be missing.

I will be upgrading a handful of workstations in late April in preparation for the roll out; I will let you know ahead of time if yours is to be upgraded early.

I will be taking mathserv down on Friday afternoon at 3:00 PM for about one hour in order to test our new emergency fail-over procedures. Web, printing, file-server and workstation access will be up and down during this period; incoming email will be on hold for the whole period.

The problem with printing to the HH-303 printer from Windows and OS X has been fixed.

Some people - me included - are having trouble printing to the shared printers using Windows or OS X. The HH-303 and HH-403 printers appear to be affected, but not the HH-105 printer. No lost jobs are being recorded for charging. For now, upload a PDF or PS file to mathserv and print from there using kprinter.

The HH-303 printer is fully operational again, with both printing and scanning working.

The scanner on the HH-303 HPLJ 4345 is not working, presumably as a consequence of the crash the week before last. The service technician was not able to get the scanner working today and will return this week.

A number of people have been blasted with spam backscatter since I first mentioned the recent storm two weeks ago.

I've modified the spam filter so that these messages (which notify you of the failed delivery of a message you never sent) are treated as spam. Note that you must have spam filtering turned on in order for the filtering to work.

The HH-303 HPLJ 4345 is not quite right after all: it prints just fine but won't scan. A technician will be here to look at the problem today or tomorrow.

The HH-303 printer has been serviced and is printing again. I had a report on Wednesday evening that the scanner wasn't working, but I won't be able to look into that until I return on Monday.

The HPLJ 4345 outside of HH-303 is still down. A technician has been out twice to work on it but to no avail so far. I have removed all jobs waiting in the queue (see full posting for details).

The HPLJ 4345 outside of HH-303 crashed Friday afternoon and won't come back up properly. A technician came out and will return on Monday with parts.

The cooling systems came back on at ca. 6 pm last night and the server room was cool again this morning. The compute servers are all running again as of 9 am.

It ends up we had spare colour toner for the Lexmark C750 in HH-401, so we have a departmental colour printer again until it runs out.

Facility Services will have the power to Hamilton Hall shut off from 6pm on Sunday May 4th to 3am on Monday, May 5th; I will bring mathserv back on line at ca 8am. Web, email, the msprime systems and the compute servers will all be down for that period.

The server room temperature is still high even with only the primary server running. It's not impossible that it will have to be shut off on very short notice. Please make sure to save anything that you're working on frequently. If you do find that your system has stopped responding, don't reboot it - it will almost certainly pick up where it left off when the server comes back up.

I will send out a notice when the cooling systems in Hamilton Hall are turned back on.

Cooling is shut off in Hamilton Hall today and the server room overheated despite the temporary A/C unit installed by Facility Services. The main server was down for ca. 30 minutes but is back up and should stay up. All other servers (bayes, bluespruce, etc.) will remain off until the cooling systems are turned back on.

A handful people using RHPCS-managed email servers have been hit by backscatter in the past week: dozens of messages reporting that email from them has been rejected by various mail servers for various reasons ("no such address", "message contains a virus", "message is spam"). This backscatter is result of a spambot somewhere on the internet using a valid McMaster email address in the forged "From:" header.

In general, a backscatter storm will result in a batch of messages arriving over the course of an hour or two and then end.

I've activated tagging of these messages using SpamAssassin but have not turned on filtering until I have a chance to see what a real tagged backscatter storm looks like. If you find yourself on the receiving end of one, please let me know before you delete all of the bounce messages.