Re: why are / and /home the same filesystem?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




> Am 07.02.2022 um 23:35 schrieb Patrick O'Callaghan <pocallaghan@xxxxxxxxx>:
> 
> On Mon, 2022-02-07 at 11:50 -0800, Gordon Messmer wrote:
>> On 2/6/22 08:17, Paolo Galtieri wrote:
>>> so why are / and /home the same device?
>> 
>> 
>> To the question of "why," I'd think the answer is in the discussion
>> held 
>> in the devel@ mailing list linked below. Generally, sharing the
>> storage 
>> pool in order to avoid running out of space in one location when
>> there 
>> was still space left in the pool due to "bad" partitioning choices
>> was 
>> seen as a benefit.
>> 
>> https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx/thread/IOPR2R3SCKOFUCKPLMS4MDD5664SGQFR/
> 
> From btrfs-quota(8):
> 
> On the other hand, the traditional approach has only a poor solution to
> restrict directories. At installation time, the harddisk can be
> partitioned so that every directory (eg. /usr, /var/, ...) that needs a
> limit gets its own partition. The obvious problem is that those limits
> cannot be changed without a reinstallation. The btrfs subvolume feature
> builds a bridge. Subvolumes correspond in many ways to partitions, as
> every subvolume looks like its own filesystem. With subvolume quota, it
> is now possible to restrict each subvolume like a partition, but keep
> the flexibility of quota. The space for each subvolume can be expanded
> or restricted on the fly.

The quote describes a situation which has gone for more of a decade now. Since we have LVM (when got that part of the Linux kernel? kernel 2.6? 2004 or so? Don’t know exactly), no one would partition a hard disk along file system subdirectories. You create logical volumes instead, which can easily "changed without a reinstallation“ and space for any logical volume "can be expanded
or restricted on the fly“. The latter even easier with „thin provisioning“. And of course you can do backups and restores via snapshot, it's called LVM snapshot. What a surprise.

And you can do all that without that "subvolume (only) looks like its own filesystem“ but in reality are not separate and independent filesystems but merely pretend to be.

BTRFS has specific advantages, without a doubt. And it is attractive for specific use cases. But it's not a silver bullet against all the tribulations of file storage, nor is it the only way to the future of IT. And by far it is not the almighty system, which fits everything as default,  as many "BTRFS missionaries" would have you believe, throwing buzz words around. 

Peter

_______________________________________________
users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx
Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx
Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure



[Index of Archives]     [Older Fedora Users]     [Fedora Announce]     [Fedora Package Announce]     [EPEL Announce]     [EPEL Devel]     [Fedora Magazine]     [Fedora Summer Coding]     [Fedora Laptop]     [Fedora Cloud]     [Fedora Advisory Board]     [Fedora Education]     [Fedora Security]     [Fedora Scitech]     [Fedora Robotics]     [Fedora Infrastructure]     [Fedora Websites]     [Anaconda Devel]     [Fedora Devel Java]     [Fedora Desktop]     [Fedora Fonts]     [Fedora Marketing]     [Fedora Management Tools]     [Fedora Mentors]     [Fedora Package Review]     [Fedora R Devel]     [Fedora PHP Devel]     [Kickstart]     [Fedora Music]     [Fedora Packaging]     [Fedora SELinux]     [Fedora Legal]     [Fedora Kernel]     [Fedora OCaml]     [Coolkey]     [Virtualization Tools]     [ET Management Tools]     [Yum Users]     [Yosemite News]     [Gnome Users]     [KDE Users]     [Fedora Art]     [Fedora Docs]     [Fedora Sparc]     [Libvirt Users]     [Fedora ARM]

  Powered by Linux