Hi everyone,

I've stumbled upon the decision to which filesystem
to choose for linux (openSuSE).

Considering btrfs/ext4/fat
First two are obviously linux perfect, but I was wondering how they will react when I hook up an external HDD or USB flash which is in FAT/exFAT

What is the most compatible filesystem - given that linux will run on most...

Thanks'a bunch

You should either use ext4 or btrfs (depending on the version of openSuse, btrfs will be default for 13.2). FAT32 is not suitable to host a Linux system. Which filesystems you use on other media is not relevant at all, as long as it is supported by your kernel.

Right, so btrfs is the future - given it's features.

Question: if a user with a FAT/exFAT/NTFS formatted usb stick hooks up - will they be able to mount/read-write files - under kernel 3.12?

Again, thank you

As long as the filesystem is supported.

Most distributions have loadable modules for nearly all available filesystems. When the device is plugged in the udev service should see it, and load any drivers/filesystem modules required.

The filesystem that you use to install Linux on is essentially irrelevant to what filesystems can be used on external media. In fact there are people with particular use cases who do not use one filesystem for the total Linux install, but use different filesystems for different parts of it, and they can still use external media (not that I'm suggesting that for you - just illustrating that you are not constrained in that way).

One caution is that BTRFS is still a little 'wet behind the ears' and isn't as tried and tested as the other filesystems that you might consider. It would be wise to be a bit more conscientious than the default in ensuring that you always have backups of any vital data on BTRFS-formatted partitions, particularly if power could disappear suddenly. Otherwise, expect a lot of no sympathy when/if you do lose data...

You might even want to check SUSE's recommendations on the subject (here is a .pdf of the materials for a talk by Eckermann at Linux Con, in particular you would want to look at the flow charts on pages 17/39 - for some more basic stuff, you could look here).

OTOH, you rightly say that BTRFS is, or seems to be, the future and if you are prepared for the fact that you might be pushing the future to come to you a little faster than it might naturally want to, I can't see anything that will stop you.

If you loose data because you don't have backups you will get no sympathy, regardless which filesystem you use.

FAT: read and write support
NTFS: read support, write support if you have ntfs-3g installed (which basically comes with any distribution or is at least available in the repositories)
exFAT: patent encumbered, so no direct support from the kernel, but some distributions have the fuse-exfat driver available, which offers read and write support.

On the other hand, btrfs will give you features you may never have thought you needed - have a read of this.
I've used it for years, and the only failure I had was a RAID10 rebuild issue after I pulled one of the disks out - while running. That was early in the support. I have now moved all my photos onto a 4 disk RAID5 btrfs array - this is reasonably new feature.

While that's true, you will have done something to make data loss more likely. And still not done the sensible thing, that you should have done, even if you hadn't made data loss more likely.

I should probably have been a little clearer that I was thinking of the situation in which you had some backups, they just weren't as recent as they should have been, but the point stands.