Monday, August 13, 2012

Fixing the charging issue for the Nexus S

I don't have an Nexus S phone as I have a Galaxy Nexus.  Someone I know came to me with their Nexus S telling me that when they plug it in, it no longer charges.   I haven't seen this issue before, so I took to Google to find the answer.

Anyway, I came upon a post by MrAwesomeNL that solved the issue and figured I would share it here as it seems quite a few people have had this issue.  It also appears that it isn't just the Nexus S having the issue.

The Fix

  1. Unplug the phone.
  2. Remove the battery and SIM card
  3. Press the power button for 10 seconds.
  4. Replace the SIM and battery.
  5. Plug the phone in, but don't turn it on.  Within a few seconds, you should see the charging symbol appear on the screen.
  6. Once the symbol appears, turn the phone on while still plugged in.  Once booted up, you should see the charging icon on the battery.
  7. Let the phone charge!

I hope this helps and special thanks for MrAwesomeNL for sharing this fix.

Saturday, August 11, 2012

Linux on the Samsung Series 9 NP900X4C-A03US

I just purchased a Samsung Series 9 laptop model NP900X4C-A03US with the intentions of installing Linux on it.  Since I Couldn't find any thing on Google with someone installing Linux with this exact laptop, I figured I would share my experience with it along with a review of the overall laptop.

Briefly,  the Samsung Series 9 model NP900X4C-A03US is a 15" Ultrabook laptop.  It is extremely thin at about a half an inch (1.3cm) thick when closed and only weights about 3.6lbs.   (1.63kg)   It comes with a 1.9Ghz Core i7 quad-core processor, 8Gb of memory, 256Gb SSD hard drive, and Windows 7 64bit Professional.

The laptop comes with three USB ports.  Two on the right side are USB 3.0 and one on the left said that is USB 2.0.  This is a big deal for me as I like to carry a optical mouse with me and I also have an external DVD burner (LITEON model eNAU708) that requires two USB ports to power it.   The laptop does not have a Ethernet port, but does have a USB to Ethernet adapter included in the box with the laptop.  It also supports not just B/G/N Wifi,  but N speeds at both 2.4Ghz and 5Ghz.  If you want to see all the laptop specs, you check it out here.

With the SSD hard drive, it took about 8 seconds to boot Windows 7 Professional.  It takes about 6 seconds to boot Ubuntu 12.04.  So far, I'm very happy with the laptop.  I hope with a few fixes, it will be even better!

On to the Linux stuff.

Linux

As a Linux Admin, my preferred distribution on the server are Redhat or Redhat clones.  I first booted Fedora 17 live cd.  Everything seem to work except the Wifi.  Rather than going ahead and installing it and trying to get the Wifi working, I booted a Ubuntu 12.04 live cd and everything worked out immediately. (mostly, I will get to that)  Since I'm also a Ubuntu fan for desktops, I was fine with installing Ubuntu so that is what I installed.

Installing Ubuntu 12.04

Since it comes with Windows 7 Professional with recovery partitions, I didn't want to lose them.  Especially if I couldn't get a distribution properly functioning on it.  First I re-sized the Windows partition and tried to install Ubuntu, but due to how the partitions were setup, the Ubuntu wouldn't allow the install on the free space.  I had no choice, but to re-partition the disk which would have blew out the Samsung / Windows partitions.  So, I rebooted the live cd, connected a USB hard drive and used "dd" to clone the SSD drive to a 1TB drive I keep for backups.  

After cloning the drive, I wiped the partitions out created new partitions though leaving 20% of the disk space free for the SSD drive to use for caching allowing faster operation.

The install went flawlessly.

Now, there are a few things that don't function correctly, but so far they haven't been that big of a deal. I have also haven't yet tried to get them working.  I will update this with the outcome once I do.

What doesn't work

Touchpad

The touchpad works fine.  What doesn't work is right clicking with the touchpad.  So far, I've only came across this issue once.  As I noted earlier, I carry an optical mouse with me and use it most of the time.

*Edit* I have located a fix for right clicking with the touch pad.  Special thanks to b16a2smith over at ubuntuforums.org.

 sudo su
 echo options psmouse proto=exps > /etc/modprobe.d/psmouse.modprobe
 reboot


Backlit Keyboard

So far, I haven't gotten the backlit keyboard lights to light up using the function key (Fn) and F9 / F10.

Screen Brightness Control

Again, using the Fn key and F2 / F3 to control screen brightness doesn't really work.  It can cause the screen to flicker, so don't keep tapping them or it will.  After it finishes, it will return to normal though.

Fan Control

Using the Fn key and F11 doesn't seem to do anything in controlling the fan.

What Does Work

Sound

 Sound works perfectly.  The Fn key with F6 (mute) / F7 (sound down) / F8 (sound up) work perfectly also.

WebCam

While I haven't used to extensively, I was able to open up a Google+ Hangout and video chit-chat with a buddy of mine.  

Just About Everything Else

Just about everything else that I have tested works fine.

What I haven't yet tested

  • The HDMI port
  • The microUSB Network adapter

Possible Fixes

There maybe a fix for the backlit issue, but I'm not sure if it will work with this model yet as I haven't tried it.  Special thanks to John Slade and his post about his Series 9 laptop for the link to samsung-laptop-dkms.

Wednesday, February 9, 2011

Hanging at Verifying DMI Pool Data...

I'm checking out NexentaStor for possible use in our operations. Currently I'm just setting up the a trial of the Enterprise version with HA fail-over and replication. I've got to whitebox servers to test on.

The setup is two whitebox servers made of the following:
  • Gigabyte GA-MA78LMT-S2 (bios vs 3.2)
  • AMD Athlon II X4 645 Propus @ 3.1Ghz
  • 4GB (2x2) G.Skill memory
  • LSI SAS3442E-R Raid card (don't like, but does work)
  • 4x Seagate Constellation ES 2TB drives. (ST32000644NS)
  • Intel EXPI930CTBLK GB nic. (as the primary and the onboard nic for replication)

I setup both, but had a UPS fall over and one of the servers wouldn't boot back up afterwards. I was getting stuck at Verifying DMI Pool Data... Genereally resetting the CMOS would fix this, but it didn't. (this is a good page for those running into this error) Usually it's the CMOS corrupted, or something in the way of the boot process. After a while I figured the master boot record was messed up, so I reinstalled NexentaStor. Well, that didn't work either and after a few hours of messing around with it, I finally fixed it. I force wiped the entire hard drives. It seems the boot sector was messed up and even reinstalling NexentaStor wasn't fixing it. While I have a raid device, I have it setup in JBOD and am going to use ZFS to manage the raid.

To clear off the entire drive, I just went into the LSI bios and told it to create and then destroy the raid. After doing that, I reinstalled and the system booted again.

Update:
It appears that there is an issue with the LSI card and NexentaStor. After reinstalling, I reboot and get the same issue. So sometimes it will boot, but once it doesn't. It's over. I think I have a choice to install a couple of drives on the MB SATA controller for the OS, or just not use NexentaStor.

I'm going to reinstall the HA setup for Openfiler for now. I've set one of these up before. While it does well, (though ZFS of BtrFS would make it 100x better) it's not polished. Actually the UI is quite buggy. I just need something that will boot for this location. I will get supported hardware for the co-locations if I go NexentaStor.

Thursday, March 18, 2010

Centralized Cronjob Management

Managing cronjobs can be easy or it can be hard. When you just have a couple of servers that do specific things, the overhead is minimal. Problems start to come up when your server count starts to grow and/or the complexity of those servers require many timed administrative tasks.

What happens when you have 25 (or 1,000) web servers that need several cronjobs? What happens when you have them zoned with five servers per zone and each zone requires different cronjobs for management?

One possible answer is using a Hudson Continuous Integration Server. Hudson will allow you to schedule jobs to be ran just like any regular crond server. It can also log any output that comes from your jobs so you don't have to pipe them to /dev/null. It can also inform you when a job fails to produce the desired effect.

The question is how do you run cronjobs on remote machines? The primary way I do it is I use the Hudson user that the Hudson server runs as. I then setup ssh keys so that the Hudson user can ssh to other servers without a password. From there, you can setup your script to ssh to the required server before it executes the job that needs to be executed.

Using NFS mounted home directories makes it even more simple. Your scripts will always be where ever you ssh too. It also simplifies setting up ssh keys since every where you go has the same ssh key.

Leveraging the power of centralization is the key to a smooth running operation that is easy to manage. Best of all, it doesn't always require expensive hardware or software.