Following on from my earlier post, I had a problem getting my tape backup working with the latest stable release of Debian on the new backup server. I use flexbackup to run my tape backup and on the older Debian installation, flexbackup would correctly set the block size of the tape and run the backup. On the latest installation, running flexbackup gave an error message running the following commands:
mt -f /dev/nst0 setblk 0
mt -f /dev/nst0 defblksize 0
Running the commands manually gave the response
mt: invalid argument `setblk’ for `tape operation’
A little research uncovered the fact that installing the mt-st package (apt-get install mt-st) fixed the problem and should be installed alongside flexbackup for proper operation on later Debian installations.
I run a dedicated backup server who’s job it is to suck up all the data files from the other servers on a nightly basis to a hard drive and then transfer the lot to tape. It’s been a little flakey lately so I’ve built a replacement which is, in line with other recent changes, a smaller, quieter and altogether greener machine.
I needed to transfer some scripts from the old server to the new and discovered that the old server was not very happy that I had yanked it’s SCSI card and DAT drive. It now failed to boot and gave me a segmentation fault instead. Selecting the recovery option from the Debian GRUB prompt didn’t help so I resorted to a trusted method using SystemRescueCD which allowed me to boot from the CD then issue the following commands:
mkdir /mnt/hd
mount /dev/sda1 /mnt/hd
This created a mount point and mounted the root hard drive partition to it. This enabled me to get at the module config files in the server’s /etc directory.
vi /mnt/hd/etc/modules
This loaded up the modules list for boot-up and I simply deleted the aic**** line to remove the SCSI module.
A reboot later after removing the CD and everything is fine again.
I could complain that the aic**** module should handle such a simple error without segmenting and locking up the system and if I hadn’t figured out a work-around I probably would but since I use linux for free, it seems harsh to moan!
When we relocated to newly refurbished offices in 2005, I had a large server cupboard built into my new office to house the network hardware and servers. The office had air conditioning and the cupboard had a number of vents for airflow. Unfortunately, our array of servers and hardware kick out a substantial amount of heat and the office air-con doesn’t result in sufficient airflow to keep the temperature in the cupboard down. It’s 9:00am at the moment and the outside temperature is about 14 degrees but the cupboard temperature is already 31.2 degrees. I’ve already had to replace two hard drives this year and we have a hot summer predicted in the UK .
The other problem with the server and network hardware is the noise. The network switch has fans which make a ridiculous amount of noise and the server PSU and CPU fans mean that the cupboard doors have to be kept closed.
Now, we are not a large company, about 20 active users at once and apart from our main file server we have an old NT server keeping a legacy SQL server application running and we have an email server and an intranet server. It could be argued that we don’t need our own mail server, particularly now that provider-supplied email services now include more services and options. However, I like the flexibility having our own email server provides.
All of our servers are standard PC kit running Debian (except for the NT server obviously!). Since there is little CPU or graphics load, it is possible to reduce the hardware requirements and be a little greener at the same time.
Continue reading ‘Green IT’
The UK votes today in European and local elections and just like every other election since 1992, I won’t be voting. More than ever now, I believe that our political system is broken. We basically have two parties (ok there’s a third but they are so far behind they are almost irrelevant) who will do absolutely anything to score points against each other and gain power for themselves and that’s all it’s about, gaining power. We have a 4-5 year cycle in general elections and the purpose of each party is to make sure that they win the next election. The public good comes a very distant second.
The recent response to the economic downturn has been a prime example. It is a case where the best solutions have to be debated and put into practice for the good of the nation and it’s people. Instead we’ve had our two main parties bickering and sniping at each other trying to knock each others ideas and score power points. As I’ve said so many times in the past, recession is more about confidence and public psychology than anything else. The Conservatives in opposition have publicy talked down the economy because “it’s all Labour’s fault” and the more damage they can do to Labour the closer the Conservatives are to power at the next election, an election which they might even be able to force the country into early even though that might not be the best thing for the economy or the country. For their part Labour have shouted down any decent ideas or policies the Conservatives have had to improve our economic situation.
What I want, and it’s for more qualified people than me to speculate as to how it could be brought to be, is for a system of consensual politics whereby the best solution is the target, not power. People need to have confidence that their elected officials are working for them, making their lives better and safer, and not simply giving platitudes while chasing power and wealth (do i need to mention MP expenses!?) for themselves and their colleagues.
What it ultimately boils down to is that I don’t belive my vote means anything, it is a means to the politicians end, not mine.
I have a wireless link between two buildings setup with a pair of D-Link DWL-2100AP access points and directional antennas. It works ok except for the usual unexplained losses of signal which always seem to plague my wireless installations. I have to admit, I loathe wireless with a passion. It has never lived up to it’s potential and I even have problems with a small setup at home where the PC and access point are only 12 feet apart!
However, that is not my specific problem here. In March, I lost the link and traced the fault to a failed PSU on one of the 2100AP’s so I swapped it out with a spare and all was well. Last week, nine weeks later, another PSU failed. I’ve replaced it again but since it was the same access point as before I am going to swap it out. If there was a problem with the access point I wouldn’t have thought it would take nine weeks to burn a PSU out?
Anyone else had any problems with recurring failure of D-Link PSUs?
I’ve been very busy at work the last few months and most of it has been pretty boring mundane stuff. As such I’ve neither had the time or the subject matter to post to the blog. However, I’m catching up with the crap at work and looking forward to some more interesting things ahead. Hopefully that will lead to a little more dedication to “A Mind Lost”!
I had to look at a laptop last week which was infected with some kind of spyware although someone had already had a go at removing it and partially succeeded to the point that the exact nature of the spyware wasn’t apparent. Websites were being redirected, often to sites that were not even available, possibly due to being already shut down. AVG couldn’t update and Malwarebytes Anti-Malware would not install and run, even by changing the executable names. I couldn’t get any anti-spyware to load even in safe mode.
I was almost at the point where it becomes time and cost effective to simply wipe the machine and re-install, when I came across a simple procedure which got me around the spyware’s defences. If you ever have similar problems, it may work for you too.
1) Click Start –> Run.
2) Type “devmgmt.msc” and press enter.
3) Click View –> Show Hidden Devices.
4) Browse to “Non-Plug and Play Drivers”.
5) Find “TDSSserv.sys” (A known trojan self-defence service).
6) Right-Click and Disable.
7) Reboot
8) Install Malwarebytes Anti-Malware and scan.
Malwarebytes found a dozen various instances of trojans and spyware and removed the lot. AVG was then able to update and websites worked correctly. Hopefully that’s the last I’ll see of it.
The hard drive on our mail server died this week, giving SATA media errors on the Linux console. I had a spare server almost ready to go so I migrated our data and configuration over to it. Everything appeared to go smoothly until I tried to send an email in from outside to test it. Every message I sent appeard in the recipient’s inbox as a blank message. No subject, no content and the To field marked as “undisclosed-recipients”.
I initially traced the problem to the spamassassin configuration in that if I disabled the spamfilter content filter in Postfix, emails were sent and received correctly, albeit they would include the 1500 or so junk messages the filter traps every day. I tried removing and reinstalling spamassassin but that made no difference and I tried running “spamassassin –lint” to test our configuration but no errors were found. Log files reported no problems.
In the end the solution was incredibly simple. If you run
apt-get install spamassassin
on debian, you get a spamassassin installation with one important feature missing, the spamc program used to actually filter the messages through the spamd daemon.
apt-get install spamc
fixes the problem. I don’t remember installing them seperately in the past but maybe I’ve just forgotten that I did!
All last week I managed to get to work despite the snow and ice here in the Midlands. However, this morning I’ve been beaten. We had a layer of snow yesterday evening and it’s frozen solid overnight. Having left for work early this morning I gave up after 25 minutes having completed only a mile of my 10 mile journey. The area is grid-locked and the roads are like glass.
I’ve been pretty supportive of the councils and highways agency in their gritting strategy. People seem to think that laying grit while it’s snowing will magically clear the roads instead of the grit just getting covered with snow! However, my local authority and the one where I work have no fear of running out of grit/salt because they haven’t used any! I live on what is considered a main road and although the snow stopped before 7:00pm last night, there is not a grain of salt on the road outside my house and people are doing suicidal speeds, oblivious that the shine on the road is actually ice until they try to stop at the roundabout just down the road!
Hopefully, once the rush hour has come and gone, I’ll be able to get to work sometime today. If not, the VPN to the office will have to be get the work done today.
According to todays news, drugs giant GlaxoSmithKline are announcing over 6000 job losses. If you believed the spin, including the BBCs report, it’s all tied in with other job losses resulting from the current recession. It is clear beyon the spin, however that this is due to increased competition and would be happening anyway. It seems that the the recession is a great cover for getting rid of staff in order to “cut costs and boost profits”!
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