JDPFu.com 2025

Below is the first of 6 questions from a reader. I definitely don’t have all the answers, but I’m not short on opinion. ;)

Part 1 – LVM+JFS+RAID | Part 2 – Service Virtualization | Part 3 – Virtualizing Media Storage | Part 4 – Hosting Email

duijf asks:

I have a total of 5 quiet 5400RPM 1TB drives configured in a RAID5+1 array. I installed Ubuntu Server 10.04 onto LVM , inside the LVs JFS is used as the file-system. Is this good practice?

This morning I saw an email from a business associate. It contained a link to an article on LinkedIn. That article was actually hosted on mashup. The article was about Social Media Overload; he called it The Sharepocalypse. After reading a fairly long article pointing out all the issues with the different human interactions with the main social media providers, I wanted to add a comment. Oddly, I couldn’t unless I used either a twitter or facebook account to login.

I’m sorry about the recent downtime for the blog this week. I was adding more internet service connections. Everything seemed to be working just fine for two days before the connection that the blog sits on took a dive into 5% usefulness. I worked with the provider for about 4 hours and we couldn’t solve it. They dispatched a tech this morning and he was able to augment what the prior tech had done, fix few issues at the tap and scheduled some updates to the signaling for this area later today – at least that’s what I heard. Whether any of that is true will be seen later, right?

We know intuitively that desktops are faster than laptops – well, most of us know that, but how much faster? I’ve written that video transcoding is 2-3x faster on a desktop than a laptop. Here’s another example where the laptop is slower than a common desktop. You should be able to reproduce this yourself.

I have used Thunderbird for at least 8 yrs and used Mozilla Mail built into Mozilla/Netscape before that. When the company started using Zimbra for email, IM, calendaring, Lightning never quite worked correctly. With v5 of Thunderbird, the integration to Zimbra with Lightning is working well. After using it about 2 months, I haven’t seen any failures – even on complex calendar settings.

Thunderbird v5 + Lightning Installation Steps

These instructions are for Ubuntu, but probably work with other distros too.

sudo add-apt-repository ppa:mozillateam/thunderbird-stable
sudo apt-get update
sudo apt-get install thunderbird  xul-ext-lightning

Sometimes I lose track of all the devices on a network and need a reminder of everything that is there. Under IPv6, you won’t scan the entire subnet – it would take millions of years – but under IPv4, you still use a scan. nmap is good for this and running it with operating system finger printing goes quickly (relatively speaking).

nmap OS finger print command

$ sudo nmap -O 192.168.0.0/24

Bare with me here. This is a great technique. I think you’ll thank me later after doing what this article suggests.

Homes and businesses today have lots of network devices. Using DHCP is the easiest way to get those on the network, but if you ever want those different devices to talk to each other, perhaps to transfer a file or to have a central backup server, then now your are running a network. Running a network means you probably want to know which devices are on your network or maybe that is just me. Perhaps you want each device to locate each other device too? Static IPs are possible under DHCP, sometimes called DHCP Reservations or Static Leases.

Make it easy for everyone in the house by using your router to force static IPs for the devices when they are at home, but still can connect to DHCP networks easily when roaming. This is really good for portable WiFi devices like laptops, smartphones, and for home entertainment devices that easily support DHCP.

Linux/Ubuntu (maybe others) – ssh key-based authentication made easier.

You know that you shouldn’t be using passwords to remotely connect to a different machine, but setting up key-based authentication has always been just a little too much hassle to bother. It really is simple, but there’s a tool to make it even easier. ssh-copy-id is included with Ubuntu-based distros (and probably others) to push the public key from your desktop to a server and append that public key to the end of the ~/.ssh/authorized_keys file.

FTP, File Transfer Protocol, has been around since the beginning of the internet in the early 1970s. It transfered files when the internet was a safer, more trusting, place. That isn’t the case anymore. Using FTP to host files is probably a bad idea for almost everyone. FTP is like Telnet. No encryption is used for anything. These days, we know that is bad.

In the mid-1990s most organizations stopped using telnet and switched to ssh, secure shell. FTP needs to be replaced for the same reasons. Below I’ll describe why very few people should use plain FTP anymore to remotely access files.

Yesterday, I was told that there was some issue with email here. Messages were bouncing. After a little research, it was determined that the ISP had decided to filter port 25 inbound AND outbound. That began around 1:50am on Wednesday morning. I know this because there are logs. Why did they change this after 12 years? I’ll never know.