gimp stuff

note to self I wanted to make my Twitter profile pic. animate. :-) It's quite easier than it might look, even I could get it done without much trouble! All that is necessary, is a bunch of photos in the sequence you want them to be animated. Easier if they are saved inside a single directory to minimize going back-n-forth looking for them. So, here is what you do. 1. Open up the 1st image in the sequence on Gimp. 2. Go to "File" on this newly opened up image window and select "Open as Layers..." and select the rest of the images to open. 3. Select "Rectangle Select Tool" and select a rectangular area with the content you want to have. ( Exact size of the rectangle in pixels will appear at the bottom part of the window. 4. Once the selection is made, go to "Image" either on the Top Menu bar or right-click context menu, and Select "Crop to Selection" 5. Now, go to "Filters" > "Animation" > "Optimize (for GIF)". This will open up a new window with the image. 6. Just to check how it will look in the end, once again go to "Filters" > "Animation" > "Playback" and play the animation step by step. -just hitting play is not that helpful cuz. frames move on quite fast. 7. Now save the file as a .gif & In the "Export File" dialogue, Select "Save as Animation" 8. In the "Save as GIF" dialogue select the option "Loop Forever" depending how you want it, and also give a decent amount of milliseconds as the delay between the frames. Also, check the tick box "Use delay entered above for all frames" :-) That's pretty much it! Check the file size before uploading it to twitter cuz. twitter has some limitation on the Profile Image size..I think 700Kbs. Used Gimp, cool tool it is!

bnx2x stuff

note to self

Experienced this issue on HP 460c G6 Blades. Host Operating System RHEL5.4 is using Broadcom Corporation NetXtreme II driver module bnx2x in this setup. Fully Virtualized Windows 2003 Server Guests could not transfer files over the network, while there is no drop of packets when tested with "ping" etc. and even the Remote Desktop Connections over RDP are working without any issue. Additionally, the Host OS's (RHEL5.4 , RHEL5.3 etc. ) doesn't seem to have any problem either. -before upgrading to the latest firmware Finally, adding

options bnx2x disable_tpa=1

to /etc/modprobe.conf which disables LRO (or TPA) on the bnx2x-based netwrok cards resoled this issue. All this above was done on HP NC-Series Broadcom 1Gb and 10GbE Multifunction Driver for Linux although it seemed to me as if the Broadcom Driver provided from RHEL5.4 it self should do the job with the above module options. Got the solve through Red Hat Support and i quote,

FYI, LRO (Large Receive Offload) is a technique for increasing inbound throughput of high-bandwidth network connections by reducing CPU overhead. It works by aggregating multiple incoming packets from a single stream into a larger buffer before they are passed higher up the networking stack, thus reducing the number of packets that have to be processed.

Now the funny thing is, when i read the above it feels like this is something i would want to keep turned on and not* off! :-) Guess its gonna take me some googling to get that one figured out.

mptlinux stuff

note to self

Experienced this weird behavior with a HP-DL580 G5, while installing RHEL4(U2) on it. The installer was looping at the detection of LSI Logic HBA adapter. Removing the card allows the installation to go ahead without any problem, but once installed and at the re-insertion of the card, the system was still getting halted at the initial device detection( some sort of a loop at detecting the HBA ). Looked to me as if some module(scsi?) being used with the device, which is not capable of handling the device properly was causing this problem. Removing the card, and then installing the mptlinux .rpm that is provided by the vendor, and then re-inserting the card solves this problem. Yet to test this with a later release of RHEL4 & 5, most probably the fix is already in place.

Nmap5 RPMs

Just built RPMs of Nmap 5, have always been wanting to work on RPM building. If you are interested in checking them out, get them from the below links. nmap-5.00-1.i586.rpm zenmap-5.00-1.noarch.rpm ncat-5.00-1.i586.rpm nmap-debuginfo-5.00-1.i586.rpm Built them on my F11 box without any changes etc. to my current setup, not sure if that's how it should be done, still not very good at this rpmbuild stuff. Hope they are working. Used "rpmdevtools" to setup the rpm build env. and followed this in setting it up. Update: The official RPMs are here.

wget stuff

note to self

RHN doesn't seem to play well with download managers. "wget" used to be good but noticed a small problem lately. When wget -c is given to resume a download, it starts to download things from scratch. This probably has something to do with the expiring urls that are given on RHN. Renaming the old file part to the new one you can identify from the new download URL will work in this. Still not sure what's causing this, but remember quite well "wget" that wget didn't have this file-name problem earlier.

simple awk usage

note to self Once again, something i can't seem to hold in my mind, and end up searching for it over and over. Awk can be used in this way to filter out a field from a text file when the separator is a " " ( WHITE SPACE ) awk '{ print $n}' $n - is the field/column number This can also be used in many other things for example, -my favourite- to take out the leading white spaces on queue_ids from grep'd and cut'd ;-) postfix logs. Thanks dhaj for showing me this trick.

timezone stuff

note to self

On RHEL4+ systems, timezone data files are kept in /usr/share/zoneinfo/ with the /etc/localtime symbolic link pointing at the correct time zone the machine belonging to. If the time zone data file doesn't contain the correct information, then the system seem to assume its on GMT. Now if the system date and time is set manually to the current localtime, everything appears normal. One noticed problem that happens in such a setup is if this machine serves as a mail server, then the mail header contains these time zone details. This can cause strange problems with MS Outlook, as outlook seem to use this value and the local machines time-zone details to calculate the display time on mails. For some reason, the mail clients running on GNU/Linux systems appears to be immune to this problem. Still have find out how the mail clients such as evolution etc. display the received time on mails. On RHELs the time zone data are provided in tzdata package, and it's important to keep that up2date, specially if it is an online system.

Setting up s/w raid on gnu/linux

note to self mdadm can be used to create raid volumes easily in the below way. mknod -m 0640 /dev/mdX TYPE MAJOR MINOR chgrp disk /dev/mdX mdadm --create=/dev/mdX --level='RAID LEVEL' --raid-devices=n /dev/sdXX /dev/sdYY RAID LEVEL can be any value from linear, raid0, 0, stripe, raid1, 1, mirror, raid4, 4, raid5, 5, raid6, 6, raid10, 10, multipath, mp, faulty. Eg: Creating a RAID 0 with 2 physical devices /dev/sda1 and /dev/sdb1. mknod -m 0640 /dev/md0 b 9 0 chgrp disk /dev/md0 mdadm --create='/dev/md0' --level=0 --raid-devices=2 /dev/sda1 /dev/sdb1 mknod is quite important, as otherwise mdadm will complain about non-existent device. Make sure to specify unused MAJOR and MINOR numbers when creating the (block)device. Refer to mknod man page for more info. As usual, i keep forgetting this important step, and keep running in to trouble. Very useful guides are here and here. Some guides seem to suggest that the s/w raid configuration should be put on to a /etc/mdadm.conf, but i think this is no longer necessary. From what i've gathered, the actual RAID configurations are kept in a superblock in member physical devices. The linux kernel identifies the and reads out that information from the physical devices( partitions ), at the boot-up, and they have to be of the type 'Linux raid autodetect' OR 'fd' for this to work properly.

SL Radio channels on mplayer

Lots of Sri Lankan online radio stations seem to require Windows Media Player plugin or some other plugin when you try to access them over the Internet. Went through a couple of those radio channels finding out which urls that can be used with mplayer. Below are the findings, hope they will come to some use. I currently only listen to YesFM, and YesFM only. YesFM -> http://174.133.224.53/yesfm TNL Rocks -> http://220.247.224.89/live Lite FM -> http://222.165.133.161/live Y FM -> http://174.133.224.53/yfm E FM -> http://69.80.238.25 Shakthi FM -> http://174.133.224.53/shakthifm Neth FM -> http://38.96.148.49:5552 Sirasa FM -> http://174.133.224.53/sirasafm MAX Radio -> http://75.125.239.34:7045 As an example, to listen to YesFM, you can use mplayer http://174.133.224.53/yesfm This link helped quite a lot in finding out the Radio Channel web sites.

vim stuff

note to self I keep forgetting this, and i want to kick my self hard so i won't!!! Even then I'm not sure i won't forget this! To append some common text to all the lines in a text file with vi/vim, below can be used. :%s/$/some text \t = Tab Space

Counter-Strike 1.6 on Wine

I wanted to play this game Counter-Strike, for some time now..and yesterday i got some free time to try this out. Actually it was pretty easy to get it to work on my Fedora9 with Wine. Only thing i had to do manually was to copy this msvbvm60.dll from a M$ Windows machine to .wine/drive_c/windows/system32/ The graphics get a bit jerky when the game is starting up, and once it loads up its quite smooth. Btw The installer wizard was filled with some strange looking characters instead of the instructions, but i guess i got the correct buttons when i clicked. Shouldn't be hard. This would be the second FPS game i had luck with over wine., Unreal tournament being the 1st.