Acer Aspire L5100 won't boot - black display only

My desktop Acer Aspire L5100 (purchased Jan. 2009) was having sporadic boot problems, and then finally wouldn't boot at all. Upon power-on, there was no display from the BIOS or any other feedback on the screen.

I had seen some problems like this after the machine went into hibernation, but I don't believe that was the case here.

Upon doing a bit of Internet research, I opened the case and checked the motherboard's battery. After pulling one screw holding the DVD/HD unit, I uncovered the battery. The CR2032 battery only had about 1.5 volts instead of its 3.0 volt rating.


Preventing SSH timeouts

Depending on the environment you're working in, you may be automatically logged out from a server by SSH timeouts. Here are a few things you can do to help prevent these timeouts :

Add or modify the following in your /etc/ssh/sshd_config file :

ClientAliveInterval 28800
ClientAliveCountMax 28800

In your ~/.bashrc file, set the TMOUT parameter to something longer. For example :

export TMOUT=28800

On your client (PuTTY) set the seconds between keepalives to something like 30.

Dokan - sshfs for Windows

jEdit has a nice SFTP plugin which allows you to edit remote files as if they're on your local machine.

I've been working with the Netbeans IDE lately. It's nice, but lacking a decent SFTP plugin.

A little searching revealed Dokan which allows you to build a ssh file system on your Windows machine.

Setup is a bit awkward. You need two downloads. One is the needed libraries, the other is a simple app/GUI which allows you to mount the remote file system as Windows drive letters N:, T: etc.

So far it seems to work as advertised. And free!


Improving performance with multi-threading on a multi-core CPU

The other day I was downloading several podcasts from the net, while doing an expensive rsync across my slow home network. My dual core CPU was showing 50% on one CPU, about 0% on the other, and my network was shown at about 1%.

My iTunes had a "download multiple streams" checkbox that was unchecked. I thought running multiple streams might actually slow things down due to thrashing/context switching, but I checked it to give me multiple streams.


Migrating to a 64-bit operating system (OS)

When upgrading servers, you may encounter this question : Should we stay at at 32-bit OS, or 'upgrade' to a 64-bit OS?

To me, the big advantage of a 64-bit OS is the ability to address (use) more than 4 gigabytes of RAM. I sometimes bump into that limit on my desktop,
so I think it's best to have a 64 bit OS for servers.

Larger memory space isn't the only advantage, however. From Wikipedia :

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