TOPIC: IMG
Changing the UUID of a VirtualBox Virtual Disk Image in Linux
11th July 2021Recent experimentation centring around getting my hands on a test version of Windows 11 had me duplicating virtual machines and virtual disk images, though VirtualBox still is not ready for the next Windows version; it has no TPM capability at the moment. Nevertheless, I was able to get something after a fresh installation that removed whatever files were on the disk image. That meant that I needed to mount the old version to get at those files again.
While renaming partially helped with this, what I really needed to do was change the UUID, so VirtualBox would not report a collision between two disk images with the same UUID. To avoid this, the UUID of one of the disk images had to be changed and a command like the following was used to accomplish this:
VBoxManage internalcommands sethduuid [Virtual Disk Image Name].vdi
Because I was doing this on Linux Mint, I could call VBoxManage without need to tell the system where it was, as would be the case on Windows. Otherwise, it is the sethduuid portion that changes the UUID as required. Another way around this is to clone the VDI file using the following command, but I had not realised that at the time:
VBoxManage clonevdi [old virtual disk image].vdi [new virtual disk image].vdi
It appears that there can be more than one way to do things in VirtualBox at times, so the second way will remain on reference for the future.
Terminology for larger and larger disk drive data volumes
3rd October 2007When I started into the world of computing at university, 200-300 MB hard drives were the norm for PC's. My own first PC had what was then thought a sizeable 1.6 GB disk, only for things to increase in size since then. Now, I have access to several hundred gigabytes of storage at home, while we are now seeing 1TB offerings for the PC market.
Terabyte storage has been the preserve of the server market, but given the disk sizes that are available now, even larger units are needed to describe the sizes of data volumes, ones that I haven't seen before. So here goes:
|
Unit |
Number of bytes |
Number of bytes |
Number of bytes |
|
petabyte |
1024 TB |
2**50 |
10**15 |
|
exabyte |
1024 PB |
2**60 |
10**18 |
|
zettabyte |
1024 EB |
2**70 |
10**21 |
|
yottabyte |
1024 ZB |
2**80 |
10**24 |
* Binary measurements are used by operating systems like Windows and Linux, while decimal ones are used by hard drive manufacturers
While I know that the above strays into the realms of esoterica, the way that things have been going may mean that we are talking about petabytes before very long. As it so happens, HP recently mentioned zettabytes when talking about its range of UNIX servers and I needed to go looking up what it meant...