JDPFu.com 2025

As some of you may know, I am a consultant, primarily with UNIX, virtualization and systems architecture. The last few days, I’ve been setting up a fairly low cost backup solution for a 100% MS-Windows shop running VMWare ESX 3.×. They have 15+ VMs and the old backup system had been shutdown and wiped more than a few months ago. There didn’t seem to be anything wrong with the prior backup solution except that the day-to-day system users didn’t know much about the setup. My task was to get that system working again.

The Tools

1. Trilead VM Explorer – the VMware compatible VMDK backup software. Not the free version.
2. Fire Daemon Pro – to run the backup task on a schedule.
3. MS-Batch – .CMD files – to selectively control which VMs are backed up on specific days without point-and-click requirements.
4. Service Accounts – this is very important in the MS-Windows world.

If you are looking for the smallest Linux possible and want to add just a few applications, then you really need to look at TinyCore.

11MB of disk, 64MB of RAM (perhaps less), 2.6.xx kernel, X11 or not, your choice. What more do you need to know?

Small Footprint in Disk AND Memory – 11MB

Do you have 11MB of Disk and 64MB of RAM? TinyCore Linux will work for you.

2014 Update:
Adobe is at it again. This time violating paid customer privacy.
Adobe spies on readers: EVERY page you turn, EVERY book you own leaked back to base

Time to start blocking adobe domains, if you don’t already.
adelogs.adobe.com is one.

Adobe has been plagued with security issues in their most popular tool, like Acrobat and Reader. These issues seem to be on all platforms, but are mostly targeted by hackers on MS-Windows. For years, we’ve known that Acrobat allowed PDF documents more access than most people need by default – JavaScript and the ability to start other programs running on the system. 99% of Acrobat Reader users do not need or want either of those features, yet, they are enabled by default.

Adobe has been slow to correct issues and claimed to be on a quarterly patch cycle. This is for Flash, Shockwave, Reader and all products including PhotoShop. For almost all of these tools, there are alternatives that are not the main targets of hackers.

So, I gotta ask …

Why are you still using Adobe Tools?

How to ask for help for Linux issues.

All of us need a little help now and again. Linux users aren’t any different than MS-Windows or Mac users in that regard. The difference is that to get help for Linux, you need to do a little more research first.

We’ll assume you don’t have a nearby Linux knowledgeable friend that knows everything. You’ll need to ask people you do not know for help. Or, perhaps you are the Linux guru in your circle of friends and your questions are more complex than most.

Below, I’ll suggest a few methods to use to get help and outline the data you should include in your requests to optimize the ability of others to actually be helpful to you.

I’ve been slightly disappointed with overall VirtualBox performance and decided to see what I could do to make things faster. For me, there are 3 elements to the performance issue. CPU, Disk and Network I/O. At this point, I only have possible solutions for two of the three areas.

My server is running Ubuntu Server x64 10.04 with VirtualBox 3.1.6 OSE directly from the Ubuntu repository. Below, I’ll describe how to improve both disk and network I/O performance. I think these suggestions will apply to other versions and MS-Windows hosts too.

Today a friend sent an email with a Gnome helper app to setup a panel so remote ssh logins could be added to the Gnome Panel. There are lots of applications, or applets, like this out there. They all read and edit config files and provide a GUI to do something that has been possible for years and years. I guess if you are new, then having a program that edits configuration files before you’ve learned to use a UNIX editor is a good thing. Noob-friendly editing is good and reduces the perceived learning curve for Linux. Long-time users know that having a program to edit simple configuration files isn’t needed. You can edit them yourself and accomplish amazing things.

Some background reading on X/Windows. Here’s an architecture image as a reminder:

Recall that the X-Server runs on the desktop and that the X-client runs on the other, sometimes remote, machine sending requests for to the specific screen to be displayed. Also, you can run many X-servers on a single machine, even if they are not physically displayed.

Nothing is New

Do a google search on “fvwm screenshots” to see what I mean. This one or one very similar has been displayed as long as I can recall using fvwm. fvwm has been around since before I started using UNIX/Linux in 1993. I didn’t find it until 1995 when it was a pioneer in virtual desktop capable window managers. At that time, people were still using wmw and twm, yes, people actually used twm. When you first started using FVWM, you wanted to configure the menu for your local needs. It was easy to get going quick and setup remote logins to other systems for everything, including telnet, ssh, email, web browsing, editing files, running desktop word processors … whatever. Today the GUI settings are still maintained inside text files and these can be customized manually. Sometimes there are a few more steps since GUI programmers today like to take a simple concept and turn it into an environment that requires many, many more config files. Still, manually adding menu items to a panel for Gnome, KDE, XFCE, or LXDE is relatively easy.

This Cyberciti.biz article explains settings and techniques to increase the default RAID re-build performance from 4k to 51k in his example. The key settings were

1. Increase the speed limit max by adding dev.raid.speed_limit_max = 500000 to /etc/sysctl.conf
2. Enable bitmaps during the rebuild and disable them after
   1. sudo mdadm —grow —bitmap=internal /dev/md0
   2. sudo mdadm —grow —bitmap=none /dev/md0

Sometimes a home or small business would like to extend a network without running any ethernet cables or using expensive power line methods. Many homes have an old WiFi router that is still working, but the new router still doesn’t get signal to all parts of the home or some devices do not support WiFi networking, only 100base-tx wired. By using the new WiFi router with the older WiFi router, it is possible to extend a network over WiFi and locate wired connections on the far side of the home using just the two wifi routers in bridge mode.

Your computer guys are always talking about some coming disaster and trying to get budget for a DR, Disaster Recovery failover location. There never seems to be enough funds. Heck, you may be lucky to get backups rotated to an offsite location.

A story in Dallas Morning News, Water-main break cripples Dallas County computers, operations explains what happened to take down the county computer systems.

Cron has been around since the beginning of UNIX systems. It is a scheduler that will run programs or scripts periodically when scheduled. The scheduling can be for a specific time annually or at the same minute every hour or any period between those. The hardest part for me is recalling the specific format of the crontab. It is very specific and any mistake will

Different effective user accounts use different crontab files, so you can run periodic jobs as yourself or some other account like root. More crontab info .

Ok, finally, on to the tips.