Thursday, June 16, 2011

importing SGH M CDs into local database

Found that only upto SGH M 244 has been imported into SGH database. PB reported that after shifting to the Dell servers, the script that imports the cd into the database failed as it had some gui components in it and not just command line. Checking the code, found the following and modified:

1. The script had a call to the binary message
which basically just displays a message to insert the cd. I have made this into an echo statement.

2. After that, had a call to the binary question

That also I turned into an echo statement.

3. Next, called the binary error
That also I changed to a simple echo statement. Then a call to question, which I turned to echo and read.

4. Next call to error and question come from which I again changed to echo and read.

5, Next came which had calls to error which I changed to echo.

6. Next, had a call to broadcastcenter, but it had already been commented out.

Importing worked after this.

Tuesday, June 14, 2011

colinux instabilities and D drive

There were some issues with our streams skipping files, and the problem seemed to be on the filesystem of Stopping the webserver on which referenced files on the D drive seemed to solve the issue. PB did some research, and said the following:

Yes, the issue could be the windows file system size or its way of dealing with long file names. But the failure in reading might even be due to Colinux. Windows has never complained in sending the data to Colinux but CoLinux always complains in not able to read the data. The Colinux change log does mention about I/O errors.

Was going through this link on Working with File Systems which says:

If you use a large number of files in an NTFS folder (300,000 or more), disable short-file name generation, especially if the first six characters of the long file names are similar.

Every time you create a file with a long file name, NTFS creates a second file entry that has a similar 8.3 short file name. A file with an 8.3 short file name has a file name containing 1 to 8 characters and a file name extension containing 1 to 3 characters. The file name and file name extension are separated by a period.

If you have a large number of files (300,000 or more) in a folder, and the files have long file names with the same initial characters, the time required to create the files increases. The increase occurs because NTFS bases the short file name on the first six characters of the long file name. In folders with more than 300,000 files, the short file names start to conflict after NTFS uses all the 8.3 names that are similar to the long file names. Repeated conflicts between a generated short file name and existing short file names cause NTFS to regenerate the short file name from 6 to 8 times.

To reduce the time required to create files, use the fsutil behavior set disable8dot3 command to disable the creation of 8.3 short file names. (You must restart your computer for this setting to take effect.) For more information about disabling 8.3 short file names, see “MS-DOS-Readable File Names on NTFS Volumes” later in this chapter.

If you want NTFS to generate 8.3 names, improve performance by using a naming scheme in which long file names differ at the beginning of the name instead of at the end.

But again, disabling 8.3 filenames systemwide seemed a bit drastic, and could lead to other unexpected problems elsewhere. So, for now we have not done the disabling.

wifi radios for radiosai

Since WorldSpace broadcasting stopped, a lot of queries about ways to listen without a computer. Found that wifi radios are quite cheap in US and UK, but almost double the price in India.

This one, for eg. is around Rs. 4.5k in the UK while in India, the listings start from 10k. Other cheaper options in India other than mobile phones are products like this Asus box for around 6k. What you have to look for in products which allow you to listen to Internet radio stations is: do they allow you to enter custom stations - if yes, then you are safe. Otherwise, do they use the Reciva online database - if yes, then also it is safe, since Sai Global Harmony all streams are listed in Reciva. If the player uses a custom database and does not allow you to enter your own stations, then you may not be able to listen to SGH with such a player.

Monday, June 13, 2011

buffering on server

Was listening to radiosai on my mobile today with wifi for long periods while lying on bed, made the following interesting observations.

1. The changeover actually happened at around 6.32 as heard on the stream, but the shoutcast server went into the interruption music for more than ten minutes more, till the signature tune finally came, around 6.44. Meaning the stream is buffered by 14 minutes due to the two servers?

2. By afternoon, the delay was around 7 minutes - The dd which was supposed to get over at 2.41 was heard to end at 2.48. So somehow the buffering delay was reduced ?!

Friday, June 10, 2011

BSNL online directory enquiry

BSNL online directory enquiry has become centralized, has changed location and needs City to be entered. For Puttaparthi, City needs to be Penukonda. Not too intuitive!

Wednesday, June 08, 2011

adjustments for mirrordome

We had some minor adjustments done to improve the looks of our fulldome projection.

  • Moving the mirror up by a few inches more now allows us to bring the horizon a bit lower in the front area of the tilted dome of the theatre.

  • Moving the projector laterally left-right corrected the tilt in the reflected image, where earlier the left side of the reflected image was around a foot higher than the right side - for this, we moved the projector physically to the right.

  • Moving the projector towards and away from the mirror, and adjusting the zoom setting allowed us to reduce the shadow area right above the mirror. Covering a larger area on the mirror makes the shadow smaller and vice-versa.

  • Using the Bright mode instead of Custom mode in the projector, the colours are a bit better though the brightness levels are quite lower. This has to be further tuned.

Wednesday, June 01, 2011

couple of queries of email migration

Today, V had a question: if he deletes a group in Google Apps, will it take 5 days for him to create a user id with the same name. It turns out the answer is no.

When you delete the group, you should be able to recreate a user of the same name immediately. The 5 day wait period only occurs when you delete a user and try to recreate a user of the same name. Deleting a group or email alias does not lock out that address for 5 days like it does when deleting a user.
Also, Google Apps seemed to have removed the online IMAP migration tool from within the Domain control panel. So the email migration has to be done using the Google Apps Migration for Microsoft Exchange utility .

Once you install it, the setup is like the screenshot for migration from gmail:

In case it asks you for changing the consumer key, you have to log in to google apps as webmaster and copy-paste the new key.

The users csv file should be of the form, google_apps_user1

(Please note that the @google.apps.domain is not required for the second field.)

Unfortunately, this tool takes a lot of bandwidth, needs the computer to be on all the time it runs, and is much slower for gmail to gapps migrations than the online IMAP migration tool. A sample run is:

Info:Start local time is: 2011:06:01 13:56:12
Info:Migration start local time is: 2011:06:01 13:56:12
Start: Now migrating user=**********
Start: Migrating Email for store=**********
Start: Migrating 105 messages from Folder [Gmail]/All Mail for store=**********
In progress: Migrated 100 out of 105 messages from folder [Gmail]/All Mail for user.
Success: Migrated 105 messages from folder [Gmail]/All Mail for store=


Info:Migration end local time is: 2011:06:01 14:25:19
Info:End local time is: 2011:06:01 14:25:19

So it took half an hour for 100 mails.

upload problems persist

As noted at the end of this previous post, upload problems persist with sftp. When using GUI tools like filezilla and gftp, we can see that sometimes the server drops the connection, then the tool reconnects and resumes the upload. filezilla is much faster than gftp, but has support for key-based auth under Settings only in later versions which are not available for the particular OS on saiwaves. Runs OK on WinXP.

Sometimes, when using sftp and it stalls, if we kill the process, then the file at becomes orphaned or something like that. If we delete the file, then also the file appears in ls. After a day or two it disappears on its own - probably when the process times out or something like that.