Stefan Helander

Improving Firefox performance on ASUS EeePC 900

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I’ve noticed that a bottleneck in Firefox performance on the ASUS EeePC 900 is writing and reading to the disk cache. It is often I wait for something on a page and I notice that the hard disk light is on indicating read/write.

One way of drastically improving the performance is to move the cache to a ramdisk as the built in flash disk in the EeePC is not the quickest one on the block. This way you might also prolong the life of the flash disk as you decrease the number of read/writes to it. The only drawback with this is that you will loose the cache content between reboots, but I don’t think that is a problem. If you have extended your machine’s ram to 2 GB (se another post about that), you have memory to spend for this, but it will probably work on 1 GB machines too.

If you are running EasyPeasy (probably in other distros too) you already have a ramdisk. Check by starting a terminal and enter the df command. If you see "/dev/shm" you have a ramdisk. Otherwise, you first need to create one (Google might be your friend in this case).

  1. Start Firefox and in the URL-bar, type about:config and press enter. Click yes on the warning about this being very dangerous.
  2. Find the key browser.cache.disk.parent_directory and right click to select Modify. If the key is not present, you right click in the list, select New -> String and type browser.cache.disk.parent_directory
  3. As the value for the key, enter /dev/shm
  4. Pull down the Edit menu and click on Settings
  5. Click on Advanced and select the Network tab
  6. Select the Override automatic cache handling and limit the cache size to for example 100 MB (so the cache won’t eat all your ramdisk).
  7. Close all Firefox and restart it.

In my case, this drastically improved the Firefox performance. 

Stefan Helander

ASUS EeePC 900 2 GB memory upgrade

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The ASUS EeePC 900 is a dear friend of mine and has served me truly for a number of years. It is not my primary work horse, but on trips it is excellent with it’s small size and low weight (even on a 14 day trip I always travel with hand luggage only). It is also a comfort when travelling to know that I am not carrying an expensive piece of equipement. This little fellow has been my travel companion to many different countries – near and far away. So I really don’t want to retire it and recently I decided to "pimp it" a little. When running a couple of applications it quickly consumes the 1 GB of RAM, so a little bit more wouldn’t hurt.

It ships with 1 GB of RAM installed and it is possible to upgrade it to 2 GB. It is actually a question of replacement rather than expansion due to the fact that there are no free memory slots. The upgrade is performed by replacing the 1 GB SODIMM with a 2 GB SODIMM.  

For specifications of the ASUS Eee PC 900, see this wikipedia page.

The memory module needed is a DDR2-400 SODIMM but 533 and 667 MHz will also work. I used a Crucial 2GB DDR2 PC-5300 667 MHz CL5 SODIMM. Note that memory modules are sensitive to static discharge. Preferrably you should at least have a grounding wrist wrap or even better if you have access to an ESD secure work place. In reality most of us will just rely on the kitchen table and being careful not to touch any connectors or metal parts of the memory module. That will also work in most cases 🙂 

  1. Unplug the power cord and remove the battery. 
  2. The memory module is hidden behind a hatch on the bottom of the PC. The hatch is secured with two screws, one hidden behind a EeePC label (possibly acting as a warranty void seal). Remove the two screws and the hatch. 
  3. Remove the preinstalled 1 GB SODIMM by pulling locking plates on the sides a bit apart until they release the module.
  4. Insert the new 2 GB SODIMM and make sure it locks by pushing it gently down until the locking plates clicks into position.

  5. Reinstall the latch and the two screws.
  6. Install battery and connect power cord.
  7. Say your prayers, press the power button and hopefully your EeePC boots up so you can enjoy your brand new 2 GB of RAM!

 

Stefan Helander

Mobile internet broadband in Latvia

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When I travel abroad I need to stay connected to the Internet, not just for fun but I have to be connected for my work. Relying only on Wifi is not a solution as I recently discovered the hard way on a trip to France. The Hotel advertised "WiFi internet" but this however, turned out to be a connection limited to only web and mail (all traffic forced through a proxy). I needed VPN to work.

The most convenient and cost effective solution is to purchase a prepaid mobile broadband from a local provider. That way I will have 3G Internet connection during my stay.

To not be forced to buy a USB modem with every prepaid mobile Internet, I purchased a Huawei E585 3G/WiFi pocket router which is not SIM locked (works with any provider). This little thing has a battery that last for a couple of hours and I only need to buy prepaid SIM-cards in the countries I visit.

I went on a trip to Latvia and my choice fell on Okarte Internet via computer. They are covering 92% of Latvia for the moment.

There are two choises – a SIM card bundled with a USB modem for Ls 9 or just the SIM card for Ls 4. It includes one week of surf (up to 50 GB) and can then be refilled. According to Okarte’s website it could be purchased on many sales points, for example Narvesen or Plus Punkt kiosks.

The first store I stopped by could only sell refills. The second store didn’t have the SIM card only so I actually bought the package with a USB modem for Ls 9, figuring Ls 5 was a cheap price for not having to run around more stores. The modem was never used, instead I put the SIM card in my pocket router.

Even though Okarte’s website is in Latvian, Russian and English nothing in the package speaks any English, only Latvian and Russian which is of little help for me.

The major problem I encountered was that there was no technical information in the package, especially regarding APN which is crucial. I looked at my network manager in Ubuntu which actually has preconfigured choises for Okarte and found out that the APN is open.lmt.lv.

With this APN set I could surf away from my resort location in Jurmala enjoying download speed at around 4-7 Mbps and upload 0,45-1 Mbps.

 

Stefan Helander

Copy large amounts of data between servers

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There are several methods of moving data between servers in a UNIX/Linux/BSD environment, for example scp, ftp, SMB-shares, NFS-shares or rsync. My experience is that using netcat is one of the faster methods if you have large amount of data to copy.

On the receiving server:

cd /  (or the base directory under which you want to recieve the data)
nc -l 1234 | tar -zxvf -

This will make netcat listen on port 1234 (don’t forget to open the port in the firewall and/or iptables).

On the transmitting server:

tar -zcvf - /data/ | nc -q 1 targethostname 1234  (replace /data/ with the folder you want to copy and targethostname with the hostname or IP-address of the receiving server)

If you have more bandwidth than computing power (i.e. a slow machine) you might want to consider to leave out the "z" in the tar commands on both sides and transfer the data uncompressed.

If you need to move data between physical locations – never underestimate the bandwith of a car loaded with harddisks (quote from a former collegue :)).

 

Stefan Helander

Ubuntu boot hangs with black screen and blinking cursor

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If this happens, check your BIOS setup device boot order. It is possible that some device has been listed before your real boot device.

In my case, my boot SSD drives had been moved below ALL PCI SCSI and there are other drives in the machine which are not bootable causing this problem for me.

 

BIOS setup device boot order

BIOS setup device boot order

Stefan Helander

Ubuntu boot hangs with black screen after GRUB

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It might actually not be hanged, but instead but you might have been kicked into an initramfs shell but it is not displaying on the screen. 

Try to boot in recovery mode or boot on a install CD or USB stick in rescue mode. Edit /etc/default/grub: 

vi /etc/default/grub

Set the following: 

GRUB_TERMINAL=console
GRUB_GFXPAYLOAD_LINUX=text 

If the GRUB timeout is very short it might be a good idea to set it a bit higher so you have a chance to make a selection: 

GRUB_TIMEOUT=10

Save and then execute: 

update-grub

Then reboot the machine and now you may see the emergency shell you are kicked into. Now you can investigate your boot problems further.

Stefan Helander

Facebook has changed my e-mail address

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Recently Facebook decided to hide all other e-mail addresses but your @facebook.com address on your Facebook profile.

After all, Facebook is a free service, so you should consider yourself "the product" rather than "the customer". Facebook’s real customers are their advertisers and not you, so they can do more or less anything with your account and all you can do about it is to cancel your Facebook account if you don’t like it. Annoying but that is how the free services works ("you get what you pay for" and "there are no such thing as a free lunch" and so on).

It is a bit irritating but easy to fix. This is how you do it:

  1. Go to your Facebook profile page
  2. Click on About
  3. Scroll down to Contact details and click Edit
  4. Click on the small circle to the right of your @facebook.com address and select Hidden from timeline
  5. Click on the small circle to the right of your preferred email address and select Shown on timeline
  6. Click on the Save button in the bottom of the popup box
Stefan Helander

Dovado routers with ZTE MF820D 4G modems (Telia)

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To be able to use the ZTE MF820D 4G dongle from Telia with Dovado routers, both units need to have updated firmwares. Unfortunately even in stores, those units seems to have outdated firmwares.

To upgrade the ZTE MF820D 4G dongle – follow this guide (Telia Sweden): http://www.telia.se/

To upgrade the Dovado router, visit Dovado’s homepage: http://www.dovado.com/firmware and follow the instructions in the firmware file.

 

Stefan Helander

System Check virus – how to remove it

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System Check is a virus/trojan pretending to be a system diagonstics tool displaying fake errors. To recover them the user will be fooled to pay for the software. Whatever you do – do not pay for it! When infected, all icons on the desktop will be hidden and the only program in the Start menu will be the System Check tool. 

Computer infected with the System Check virus

I tried to follow the instructions here to remove System Scan virus. However, the virus seems to exist in a newer version where the Run and Search fields in the Start menu are disabled. Because of this I had to take a different approach.  Read more

Stefan Helander

My YouTube videos not displaying in related / suggested videos anymore

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I have a YouTube channel where I post videos from different strange things I am up to. Suddenly I noticed the video shows dropped significantly. The statistics (analytics) showed that the majority of my video views came from "related videos" (also sometimes referred to as suggested videoes). 

Some Googleing on the subject didn’t really turn up with a reason or solution but I found people with similar problems and someone said YouTube has a function to disable your videos from related videos if you view your own videos repead number of times, possibly trying to "boost" your view counter. 

This wasn’t happening in my case but I do use to visit my own channel as it is a quick way to see it’s number of views. The featured video on my channel is on autoplay – so yes, every time I visited my channel I also triggered one of my own videos. 

After that I haven’t visited my own channel for two months and last week the statistics starts to show that the views coming from related / suggested videos are climbing back to the levels two months ago. 

I haven’t been able to verify this with YouTube but my advise is – don’t visit your own YouTube channel or your own videos unless you are logged out from your YouTube account.