13.2 proposes druing installation btrfs for / and XFS for /home.
I therefore assume that there are advantages for the specific file system of the respective “purpose”.
What would I choose then if I don’t have /home in a separate partiton?
XFS or btrfs - or ext4?
Is this just a theoretical question, or are you rrealy planning to have no separate partition for /home?
BTW it is partly a question of personal taste, thus you will get several different advices I assume (I have still all on ext4).
In any case, when you go for Btrfs, you need some extra space for the snapshots and/or switch snapshotting off.
AFAIK, if you choose to have /home on the / btrfs partition, a subvolume is created for /home with snapshotting turned off.
So your /home should not be snapshotted by default, you’d have to enable it manually IIANM.
As a general remark, I would say that the ultimate desission if a directory (and all that is in it) should be made a subvolume is to be made by the system manager. The same as the decission to put it on a separate file system.
Isn’t that creating of a subvolume for /home not offered as a default by the installer that can be changed at installation time ? Like the installer offers as a deafult (to be changed at installation time at will) to make /home a separate file system.
It depends less on whether /home is separate, and more on what you’re going to be doing on the machine. Doing lots of DBMS-like I/O? I’d pick xfs. Want features such as snapshotting? use btrfs. Not doing anything particularly unusual and just want it to run? ext4 is a good just-works choice. (although to be fair, I’ve had no problems with xfs either.)
The only problem I’ve personally observed using the three filesystem types was some very (very!) poor performance on btrfs when a critical use is latency-sensitive O_SYNC file writing, such as a database write-ahead log file. I think I last tried it with 13.1 so who knows, that might have been fixed by now.
Of course.
But the installer has to have some default settings. And I was talking about the defaults.
At least I’m pretty sure that a separate subvolume is created for /home by default. I’m not 100% sure that snapshotting is disabled, but I think it is. I remember reading somewhere that that’s exactly the reason why it is a separate subvolume at all.
Isn’t that creating of a subvolume for /home not offered as a default by the installer that can be changed at installation time ? Like the installer offers as a deafult (to be changed at installation time at will) to make /home a separate file system.
Yes.
You can add/remove subvolumes at installation time.
And if you untick “Create a separate /home” (or whatever the option is called exactly), it is created as separate subvolume by default (unless you switch to a different filesystem of course).
And you can add/remove subvolumes later as well, in the running system, easier than changing the partitioning.
It looks as if it all doable at installation when you take care.
But I find it debatable that the installer, after you told it not to create a separate /home (where you most probably have a reason to not have /home different from any other directory in the system, e.g. because you will have no real end-users on it and the system is more for providing services), the installer insists on treating /home as something special. And you have again to redress that.
Like a cockroach, difficult to killl it rotfl!
Well, it creates other subvolumes as well, why should it not create on for /home in particular?
And a subvolume is not the same as a separate partition.
See https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-subvolume, in particular:
Although in btrfs, subvolumes/snapshots are treated as directories, only subvolume/snapshot can be the source of a snapshot, snapshot can not be made from normal directories.
So it makes sense that /home is a separate subvolume I’d say.
My view is the other way around. Why should it treat /home different from any other directory. Maybe I must stress again what I said above, I have a system where /home is of no particular value. No end-users, except maybe one or two for managing services/databases the are delivered by the system, but all they need is in the diretories created for those services (compare with /srv for a web-server). The home directory is only there because login must be possible. The most important things there are .profile and the like.
Now that is not a system as most people may use it, but I have it and I decide then NOT to have /home a partition, because there is no use for those few MB to have it as such. But then the installer decides that I maybe a bit nasty not to want a partition for it, but then you certainly want something else to make it different from other directories.
I will not refer to insects, but to a salesmen who offers me a car and when I tell him I do not need wheeled transport, then immedialtly comes back trying to sell me a bike.
Maybe I do not understand enough about snapshots and we are now way off the OPs original question.
Because it does make sense, maybe? 
Only having /home a separate subvolume makes it possible to have different snapshot (and other) settings for /home.
E.g. you may want to have regular snapshots for / (i.e. the system), but not for /home.
Or you might want to have encryption for /home, but not for the system (for performance reasons).
And again, a subvolume is something completely different than a partition.
As a user (or even system administrator) you probably won’t notice any difference to a normal directory. It looks like a normal directory, it feels like a normal directory, it behaves like a normal directory.
Maybe I do not understand enough about snapshots and we are now way off the OPs original question.
I agree.
It is all a personal decision, and you will get all types of differing and opposing advice, as Henk pointed out.
Wish to keep it simple? Use ext4 throughout.
Why not put /home in a separate partition, often much more advantage to that? However, it again is a personal decision.
I still have not decided which file systems I will use when I do my next 13.2 install, thinking about using the suggested btrfs and XFS.
If you do decide to try that combination, I would suggest that you read through some of the numerous threads here with information about btrfs to get a feel for why there seems to be such a wide range of opinions.
From what I understand by following several of these threads, and from technical information I have looked up online about the btrfs filesystem, I have come to the personal conclusion that btrfs is a good system worth looking into. But, I also believe you should be aware of what might be involved when you go that route.
In any case, good luck with your decision.
On 2015-01-15 17:16, hcvv wrote:
> But I find it debatable that the installer, after you told it not to
> create a separate /home (where you most probably have a reason to not
> have /home different from any other directory in the system, e.g.
> because you will have no real end-users on it and the system is more for
> providing services), the installer insists on treating /home as
> something special. And you have again to redress that.
Having no separate home has also use on non-server machines: less waste
of free space on small disks.
I think it is very sensible default to add a subvolume for home. It
doesn’t “waste” space as a partition would do, and allows finer control.
You get a dozen or more subvolumes, anyway, with btrfs… You could add
more, like one for documents, and enable snapshots in there, because you
want versions of your files…
I would be interested in that. In the old VAX VMS, when you edited a
file you got several numbered backup versions, not only the last one.
Very useful when learning programming. btrfs does that on steroids…
kind of.
–
Cheers / Saludos,
Carlos E. R.
(from 13.1 x86_64 “Bottle” at Telcontar)