Wednesday, March 31, 2010

free space on colinux and hard disk performance

Over the last two days, there were several interruptions on our streams. Problem seems to be excessive Hard Disk usage, since copying files was taking a very long time. But at a time when the system was behaving normally, trying out the counters
1. PhysicalDisk: Avg. Read Queue Length Should be less than 2
2. PhysicalDisk: Avg. Write Queue Length Should be less than 2
3. PhysicalDisk: % Disk Time more than 50% indicates a bottleneck
as given here indicates that the disk is fine. That page says
to ensure that it was not a processor or memory bottleneck, I also recorded % processor time and available bytes. As you can see from Diagram 1, the processor's average was below 30%. If the processor were the bottleneck the trace would be over 80%. On the other hand, if there was a memory shortage, available bytes should drop below 10MB.

And our processor usage was < 20%, with > 200 MB of memory also available.

Maybe I should try the same checks when the system is crawling. If there is some indication of what application is causing the hard disk usage in some log somewhere, it would have been useful. I suspect IIS, since SSSBPT and the audio downloads are also on this machine.

Checking the colinux virtual machine, found only 100 MB free, 10%. Cleaned up to make it around 40%, 400 MB or so, by the following.

apt-get clean cleaning out /var/cache/apt

As given here, postsuper -d ALL
for /var/spool/postfix

from /home/sgh/playlist,
ls ????09* to find the 2009 playlists, removed them and older ones...

Some interesting info:
2007 Feb asia/africa/america started
2004 Oct started web stream

for /home/sgh/log

mv 0*.check ../audio/log_backup 2> /dev/null
mv 1*.check ../audio/log_backup 2> /dev/null
mv 2*.check ../audio/log_backup 2> /dev/null

etc - the errors to dev null, because mv complains that it cannot keep the same user ownership and permissions.

tail -5 logfile > logfile did not work, so had to do
tail ices.log > icesnew.log
mv icesnew.log ices.log

after taking backup.

But tho playout continues, log file is not appended :(
only after playout restarts next day? Anyway, had to restart all playouts by restarting colinux service since the streams started skipping, so the logs have restarted now.

Sunday, March 28, 2010

midi works tho' audio is dead

The Yamaha AW4416 came back some weeks back after a stint at Chennai, with no improvement. Apparently it can't be fixed without a high cost. The audio output is dead, and I believe the inputs are dead too. Some of the switches are also not working. Tested the midi connections today by connecting to laptop like in my previous post through a Tascam US-144. The Midi section seems to be fine. They seem to be getting a firewire mixer at the Studio. Then maybe I will get the Tascam US-1641 once again.

Tuesday, March 09, 2010

hardware debugging - cordless door-bell

A cordless door-bell which K got for me had a funny problem. When I affix the remote switch on our door, it would not work. Remove the switch from the door, and it works, though it is at the same distance from the bell. When KR fixed it to the wall instead, it worked. So, in retrospect, it was probably some sort of capacitive effect from the aluminium door frame acting through the plastic case which was changing the transmission frequency or something.

asp error '8004020f'

BT subscription feedback form returned this error. The many-headed say this means that the e-mail was rejected by the server for some reason. Checked the asp code, it had
Fields("") = "localhost"
which listed the wrong smtp server. Corrected it and it worked fine. A wrong email address, as mentioned here, leads to asp error '8004020e'.

Friday, March 05, 2010

shopping cart code and digital downloads

A google ad on this very blog pointed to which looks pretty useful. Free shopping cart code for google checkout and paypal. Of course, many hosting companies offer free shopping cart code with their hosting too... And DigiVendor seems to be a useful MySql-Php secure downloads payment option. The Google Checkout API docs detail the process, and provides sample code, too. Similar stuff exists for paypal.

Thursday, March 04, 2010

ebook reader for Nokia 6303

Struggled quite a bit for helping V find an ebook reader for his Nokia 6303 classic. C mentioned that it was an S40 phone and not an S60 phone. That helped the google searches. Mobipocket's java version had some signing bug which was not allowing it to work properly. I sent him this list,


Libris is not free, $10

Wattpad reader
free, but supposed to read books from their website, I don't know if you can read your own files.

Wikitome reader seems to be for Series 40, so may work on 6303

Again, getting books in that format?

And he replied with his solution, MTextReader, which seems much better, and free too.

Monday, March 01, 2010

disabling google buzz in a corporate or academic network

R wanted some way to block google buzz at work. According to him, too many people were spending too much time on Buzz, with a spike in network bandwidth. And following friends of friends and other such undesirable activities. This was my reply.

This question has been asked in gmail support forums also, but since
buzz is integrated into gmail, it seems difficult to block it using
traditional methods. Here is one way I can think of:

Make the user log in to gmail using an older browser, or a browser not
supported in the latest gmail version. For example, I am typing this
in Opera 8.53 - available from - then, buzz is not even
seen. It is not using html view, either - it is using the older
version of gmail, which you can see from the url
This version has most of the useful things like address completion and so on.

(If you can redirect users to this url when they go to gmail also, it
might do the trick.)

One way of forcing users to use an old browser would be to allow gmail
only on terminal sessions running on a terminal server or remote X
sessions running on a linux server or remote desktop sessions. Since
the user is just logging on to the server, permissions can be set so
that the user cannot install any sw. Possibly such permissions can be
set on the desktops also.

Edit: R says it's not practical for him to change user settings. He will explore a url rewrite using squid's php rewrite or something like that, to redirect any requests to to