How To


There are times when you want to create an archive of many files or even one large file but need the archive file to be smaller than some file size limitation. In my case, I needed to move 90GB of data literal over 1 million files over FTP. ( There is a story behind why it was done this way.) You do not want to move a million little files over FTP. You can get better performance by creating one large file or in my case about 26 TAR archives that were 3.5GB in size. The files were to be moved to a FAT-32 external hard drive prior to sending them via FTP. The Max file size for FAT-32 is 4GB. At least when I tried to create TAR files larger than that I would get an error. The 3.5GB files size worked well.

This works on Linux and Mac OS. Open a terminal window. Then run the following command:

# tar -cf – [source] | split -b 3584m – archive.tar

This will produce a series of TAR files from your [source] file/folder with the suffix of:

taraa, tarab, tarac … taraz, tarba, tarbb …

and so on. It will append the alpha series to the suffix of the archive. Then on the destination terminal run:

#cat archive.tara* | (tar x)

That will assemble the split files and extract the archive in to their source files.



I recently purchased a new 1TB external hard drive for a project. Now that the project is completed I wanted to re-purpose the hard drive for use as a backup drive with my Mac as a target for time machine.

I initially went to the ‘Disk Utility’ application in my utility folder to format the drive. However, each time I’d format it I received an error saying the format system failed when trying to format any of the Mac OS formats. It would format FAT-32 fine but not Mac specific formats.

It turns out that you have to select the parent drive in ‘Disk Utility’ then click on the Partition tab. There select 1 partition. Then click on the options button and select the first item GUID for Intel macs or second item Apple Partition for PPC Macs. Then click ‘OK’. Now click ‘Apply’ button (for Leopard) or ‘Partition’ button (for Tiger) .

You now have a Mac OS compatible external hard drive that can be set to boot your Mac if needed.

The issue is that most external hard drives come formatted as FAT-32 or NTFS with a windows partition. By changing the partition to GUID  or Apple Partition we can format the drive Mac Extended Journaled or any other Mac OS format.



Moving the Email

In planning for my trip I needed to figure out how to get my email from my Mac to my wife’s Windows Vista laptop. I converted my email to Thunderbird around the new year due to Apple mail issues I could not figure out. So This is what I found. makes a portable windows version of Thunderbird that you can install on a flash drive. It turns out that Thunderbird uses the same data files for all platforms even for the email configuration. So all I had to do was copy the Thunderbird folder from my Mac OS user library folder to the flash drive. Go to my windows laptop. Install the portable Thunderbird from here

Then mock up one email account with a local folder. Then replace:


with the copy from my Mac OS Thunderbird profile. I opened portable Thunderbird in windows and all my mail was there. I’d have to test more to see if attachments are there too. I’m guessing they would be or maybe another file needs to be replaced. I’d also make the leap that you can move email from windows to Mac OS in a similar manor.

Test and test and test before working with real data. Create a new user on each computer to work with a copy of any data, NOT the live account.

Securing Your Email On Your Flash Drive

Now run back to the beginning. Email is sensitive and portable devised can get lost. Create an encrypted portable disk image on the flash drive prior to installing portable Thunderbird. Pick one below. Select a cross platform tool.

  • VeraCrypt is open-source and code audited, improves on TrueCrypt, works on Mac and PC, and allows creation of encrypted containers
  • Ciphershed is another TrueCrypt fork, works with old TrueCrypt containers, is slow with updates, and works on Mac, PC, and Linux

Install and place data in encrypted portable disk image.

Now you can mount the disk image to run your email and should not have worry about loosing your flash drive if your email has sensitive data in it. Obviously you will want to backup your flash drive regularly.

AGAIN … YOU WILL WANT TO BACKUP YOUR FLASH DRIVE REGULARLY, honest your flash drive will die at some point. It’s only a matter of time.


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