Me – Page 4 – Ryan Schulze

How to use Cluster SSH (cssh) and Mosh together

May 7, 2012May 7, 2012Ryanbash, cssh, mosh

A colleague told me about mosh today, just saying “it’s an alternative to SSH that addresses many of the problems” doesn’t do it credit. Go look at the page and have a look, don’t worry it’s a nice page and I’ll still be here waiting when you come back. I do a lot of work on servers across the globe, and believe me, although subtle, the difference between a 10ms connection and a 100+ ms connection is definitely noticeable 😉 That lag all but disappears with mosh. Mosh doesn’t support X11/SSH-Agent forwarding yet, but it’s on their roadmap.

Back to topic, I also use cssh for working on multiple servers simultaneously. I’d recommend making a copy of your .cshrc file (cp -a ~/.csshrc ~/.csshrc_mosh) and working on the copy. Edit the ~/.csshrc_mosh and change the lines ssh= and ssh_args= (diff of my files):

$ diff .csshrc .csshrc_mosh 
27,28c27,28
&lt; ssh=/usr/bin/ssh
&lt; ssh_args= -x -o ConnectTimeout=5
---
&gt; ssh=/usr/bin/mosh
&gt; ssh_args=

$ diff .csshrc .csshrc_mosh

27,28c27,28

< ssh=/usr/bin/ssh

< ssh_args= -x -o ConnectTimeout=5

---

> ssh=/usr/bin/mosh

> ssh_args=

You will have to remove any parameters in ssh_args= and move them to your ~/.ssh/config due to the difference in command line parameters between mosh and ssh. Now all you have to do is call cssh with the new config file, e.g. with an alias to make things easier alias mcssh=”cssh -C ${HOME}/.csshrc_mosh” And your done.

Floor plans for PAYDAY Map “Diamond Heist”

March 3, 2012March 3, 2012Ryan1 CommentGaming, gfx

I’ve played PAYDAY the last few weeks, it is a 4 player CO-OP FPS (think of Left 4 Dead in a different setting). One of the maps has caused me a bit of difficulty (Diamond Heist). There is an achievement called “Are Those The Blue Ones?” where you have to collect all the sapphires before the alarm goes off, and I kept forgetting where they were. Also keeping track of the cameras was a bit of a pain, so today I threw them all together on a map for easier reference (right-click “Save link as …” to download):

Graphics sources:
http://www.overkillsoftware.com/payday/
http://openclipart.org/detail/125695/diamant–diamond-by-lmproulx
http://openclipart.org/detail/31891/surveillance-camera-by-maxim2

Playing around with DD-WRT

December 24, 2011Ryanaccess point, asus, dd-wrt, IDS, linux, security, wifi, wlan

I’m currently playing around with my two WL-330GE Access points from asus (see an older posting). Since that posting I was a bit creative using the existing ethernet cabling and ports in the apartment to be able to retire the WiFi bridge without having any cable going through the apartment.

So I decided to use the two access points for something more useful. I’m playing around with dd-wrt to build configurations to use them as WiFi probes (for an IDS), or as Rouge Access Points (for demonstration purposes and to test wireless IDS solutions). I might compile my own dd-wrt version for the rouge version, there are a few things I miss to build a truly evil device.

I like the size of the devices (very compact) and that you can power them with 5V (you can run them off any USB port, right now the one here is hooked up to the USB port of a printer intended for cameras) the only thing missing to make them perfect would be Power-over-Ethernet and maybe a GSM interface to upload data online.

Fun having a cheap and small device like this with Wifi and ethernet running linux. Provides lots of possibilities and fun.

How to increase Fraps performance with a ramdisk

November 10, 2011September 27, 2014Ryan2 Commentsbattlefield 3, fraps, IO, powershell, ramdisk, Windows

I recently started playing Battlefield 3 and remembered that I have a Fraps license so I installed it and started recording some stuff. Unsurprisingly the performance made a big dip when I recorded. A glance at my PC told me the harddrive was at fault, probably bringing the whole system down due to IO.

Since my PC has more than enough RAM I decided to set up a 5Gb Ramdisk to see if that helped. It did, when writing the video files to the ramdisk I hardly had any performance hit. Unfortunately 5GB isn’t going to last long while recording 1920×1080 @ 40FPS (a few minutes footage at most).

Here is my little cmd file to create a 5GB ramdisk as drive J: and format it for usage:

imdisk -d -m J:
imdisk -a -t vm -s 5G -o rw -m J:
format J: /A:64k /V:Ramdisk /FS:NTFS /Q

imdisk -d -m J:

imdisk -a -t vm -s 5G -o rw -m J:

format J: /A:64k /V:Ramdisk /FS:NTFS /Q

So my next thought was to see if I could write a script to move files off the ramdisk when they were done being written to by Fraps. This obviously was going to cause IO load … the reason we were having performance issues in the first place, so I was skeptical about if this was going to help any. Especially since I also had to move the files away quick enough so that the drive wouldn’t fill up completely with the next file Fraps was writing. I wrote a little powershell script for this (yeah, a *nix Sysadmin writing scripts in powershell …)

Here is my little powershell script to copy the finished files from my ramdisk to a normal HDD (please excuse possible ugliness, I’m a powershell noob):

$source = "j:\*.avi"
$target_dir = "f:\fraps\movies\"

while ($true) {
    $files = gci $source
    foreach ($file in $files){ 
        $srcfile = echo $file.fullname
        $dstfile = echo $file.basename
        if ($srcfile) {
            try {
                move-item "$srcfile" "$target_dir$dstfile.avi" -ea stop
                "$srcfile Moved"
            }
            catch {
                "$srcfile in use, cannot be copied right now"
            }
        }
    }
    sleep 5
}

$source = "j:\*.avi"

$target_dir = "f:\fraps\movies\"

while ($true) {

$files = gci $source

foreach ($file in $files){

$srcfile = echo $file.fullname

$dstfile = echo $file.basename

if ($srcfile) {

try {

move-item "$srcfile" "$target_dir$dstfile.avi" -ea stop

"$srcfile Moved"

}

catch {

"$srcfile in use, cannot be copied right now"

}

sleep 5

}

The last little problem I noticed is that the 5GB ramdrive wasn’t big enough (Fraps seems to create some dummy files and fills them up). Forcing Fraps to make smaller files by toggeling the recording fixed that though -> pressing F9 twice fast will drop a few frames though. I used my Logitech G13 for that, just had a key mapped to press F9 quickly every 60 seconds. The shortest gap I could get working reliably is 50ms.

This all probably sounds awfully complicated, but it works and solves my problem. Fraps is great software, but it would be immensly helpful if you could set the file size in the settings (instead of it defaulting to 4GB). Or, even better, if Fraps could rework their IO system to work more efficiently.

So to sum everything up:
– create ramdrive
– start script that copies files from the ramdrive to a normal HDD
– set fraps to store videos on the ramdrive
– start game, press F9 to start recording and then press the G13 key to toggle the F9 periodically