Try New Technology

Mostly tossing this up here for my own use in referring back. Below is what needs done to ensure afacli can be ran correctly from script after a reboot. The issue is the PERC 3/Di card software for CentOS/Fedora Linux doesn’t rebuild the /dev/ files correctly and so when we run an internal raid check script it errors out with the following output:

/usr/sbin/afacli: line 13: /dev/MAKEDEV.afa: No such file or directory

The solution to this is to first run

cat /proc/devices

which will give you the Device ID for the “aac” (PERC 3/Di). Example:

Character devices:
1 mem
196 dahdi
253 aac
254 pcmcia

Next you want to add the following line(s) into /etc/rc.local (as many times as needed, so in my case with 7 errors I need to have afa0-afa6):

/bin/mknod /dev/afa0 c DEVICE_ID 0

I had to create a set of Cacti Templates for use with Redline RDL-3000 PmP radios and thought I’d upload the Exported Template for others to enjoy. I’ll add this to the official Cacti Templates sometime, but for now youw ill fine a link on this page.

This is directly from Linux Journal (Aug 21, 2008) and is posted on site blog as a point of reference for myself.

If you have ever had a hard drive fail on a remote server you may remember the feeling you had after trying to issue the following commands:

# reboot
bash: /sbin/reboot: Input/output error
# shutdown -r now
bash: /sbin/shutdown: Input/output error

Obviously, there is a problem with your drive. These commands are failing because the kernel is unable to load the /sbin/reboot and /sbin/shutdown binaries from the disk so that it can execute them.

A fsck on the next boot might be able to correct whatever is wrong with the disk, but first you need to get the system to reboot. If your machine is located at a managed hosting provider then you could submit a reboot ticket, but you’ll have to wait for someone to take responsibility.

Wouldn’t it be nice if there was a way to ask the kernel to reboot without needing to access the failing drive? Well, there is a way, and it is remarkably simple.

The “magic SysRq key” provides a way to send commands directly to the kernel through the /proc filesystem. It is enabled via a kernel compile time option, CONFIG_MAGIC_SYSRQ, which seems to be standard on most distributions. First you must activate the magic SysRq option:

echo 1 > /proc/sys/kernel/sysrq

When you are ready to reboot the machine simply run the following:

echo b > /proc/sysrq-trigger

This does not attempt to unmount or sync filesystems, so it should only be used when absolutely necessary, but if your drive is already failing then that may not be a concern.

In addition to rebooting the system the sysrq trick can be used to dump memory information to the console, sync all filesystems, remount all filesystems in read-only mode, send SIGTERM or SIGKILL to all processes except init, or power off the machine entirely, among other things.

Also, instead of echoing into /proc/sys/kernel/sysrq each time you can activate the magic SysRq key at system boot time using sysctl, where supported:

echo “kernel.sysrq = 1” >> /etc/sysctl.conf

If you would like to learn more about magic SysRq you can read the sysrq.txt file in the kernel documentation.

by Cory Wright

Busy trying to fix or at least recover the data off the emmc of my friends Droid 3 lead me down the road of using RSD to run an OTA flash on the device…more about that shortly. So here is the quick and skinny for anyone else in the same boat as he was/is:

• Touch is completely dead (no function in bootloaders like SS3/Safestrap 3 or ClockworkMod) and will not respond.
• Last time it was connected to PC you had it set for anything except a mode that allowed the EMMC to be mounted in your My Computer (in this case Charge Only).
• Your screen unlock option is swipe (vs a code that you could use the keyboard for, this is a Droid 3 after-all so use your keyboard!)
• This is a Droid 3 on VWZ, if your using some other carrier look around on XDA and Google and you might find something for your OTA.

First reboot into Safe Mode (Hold OK button on physical Keyboard as you power the unit on, until you are fully booted into Safe Mode – Lower Left Corner) and plug it into a PC to see the EMMC will mount. For me this didn’t work most likely because of the swipe to unlock method being used and since the screen was truly dead it didn’t respond in here ether. This is just to double-check that your screen is really dead.

Second:

1. Run “Flash Verizon DROID 3 OTA 5.6.890 to phone_psouza4” that I found on XDA and follow the instructions that come with it (basically boot into Boot Mode Selection Menu* and select AP Fastboot while having “Flash Verizon DROID 3 OTA 5.6.890 to phone_psouza4” running actively,
2. and plug the phone into USB at which point it should start the OTA Recovery process.
3. After it’s all done (phone will reboot a few times, wait until the app on the PC tells you it’s done) you’ll be at the default “new phone” setup screen.
4. You should then Power Off your phone,
5. disconnect the USB from the PC,
6. boot into Safe Mode (Holding OK button on keyboard while powering on)
7. and plug in the USB at which time I was able to get the EMMC to mount and pull all the data off the phone (well all that shows from within the EMMC when it mounts to Windows).

NOTES:
*To boot into Boot Mode Selection Menu have the phone turned off, then slide open the keyboard and hold down the M key while you power the unit on. A black screen should appear and you can use the DOWN Volume button to navigate and the UP Volume to Select.

Had an odd issue today I had to fix on a laptop with Internet Explorer 9 running under Windows 7 64-bit. The browser to load slowly and hang at times and then when it would be running web pages would load very slowly. After a lot of trial and error I found an article on Microsoft website where people were talking about how they had to remove KB2699988 to fix the problem. I ended up removing KB2699988 (isn’t trying to re-install now?), disabling “Enable Protected Mode” (under Security tab of Internet Options) and for this laptop I also had to turn on “Use software rendering instead of GPU rendering” as found under the Advanced tab of Internet Options.

Mostly posting this here so I remember how to fix it in the future and maybe someone else will fix this useful.

P.S. I wouldn’t advise removing KB2699988 unless you have too.