I need to extend the / directory to enable me to install a .deb file of Steam.

This is my current setup:

https://www.dropbox.com/s/cp4w79y26o...ayout.png?dl=0

Is it possible to do this now or should I start from scratch (Oh no!) and make /; /lib; /bin; /home and /data partitions?

I promise to do this in future but hopefully not this time.

Shrinking /home first (shink it to the right to make room for / to grow)and then after that worked, growing / with gparted should work. There are no guarantees though. You need to be using gparted booting from a linux liveusb and not booting from your hard drive to accomplish this as a mounted partition cannot be shrunk/grown.

Thank you.

IMHO there is very little to be gained by carving out separate system partitions unless you know you have a specific requirement. The current size of the root should be plenty in normal circumstances. Certainly add a separate partition (now) for whatever when you free up the space as suggested. I have my photos like that. That big NTFS partition might also be a good candidate to donate some space - gparted will handle that too.

But first, check out LVM = Logical Volume Management, which your Linux distro might have installed by default. (For example, in a command-line shell, does the lspv command do anything?) If not, it is possible to convert to it.

To satisfy this requirement, you would simply "add a new physical volume (partition?) to the appropriate "physical storage pool," then extend the filesystem to recognize the new space." Done. Zero downtime. All of the drives work in tandem, but anonymously, to provide space to the pool.

LVM disconnects logical volumes ("mount points") such as "/" from any direct correspondence with physical devices or partitions. Physical resources are assigned to "physical storage pools," and multiple devices can contribute space to the same pool. Logical volumes are assigned to a pool, which means that any particular file could be on any – or, several – physical device(s), "and it would be none the wiser."

LVM can also do a lot of other cool tricks. For instance, if one particular drive starts "making ominous clicking noises," you can migrate all of the data off of it without downtime, as long as sufficient space is available elsewhere in the same pool for whatever it now actually contains. If you've just bought a new solid-state drive and want to move everything from a particular spinning-drive or drives onto it, you can do that also ... without shutting the system down.

In short, LVM allows you to manage both the logical picture ("what Linux applications see") and the physical picture ("what storage devices see") independently. And, "without downtime."

If you're not using LVM on your system right now – and it's quite likely that you actually are – move to it at once. You'll be very glad that you did.

I like your touting LVM. I have used it for years and love it. However, if you looked at the disk arrangement shown in the post you can see the OP is not presently using LVM. Also, LVM has nothing to do at present with his current question.

To @makem
The 35G of space with only ~8G used in / should leave a great plenty space to install steam with no worries. If the space starts to run short later then maybe it would be time to adjust things, but I would not do that now just because you think it might happen.

HMMMMM ? I just created a thread as to why everyone should have 2 distros on their drive.
This thread explains it.

Serious overkill. As mentioned a liveUSB works just fine - most people can probably use the USB they installed from without having to do anything extra. Easy.

Thank you all, I now have enough to continue.