[Discuss] File systems that support file cloning

[Derek Atkins]

On Thu, November 17, 2022 8:43 am, Rich Pieri wrote:

[snip]
>> The only feature that I desire that xfs doesn't have is file system
>> shrinking.  It does have file system expansion, and oddly, it is
>> *only* available when the file system is mounted.  I'm a little
>> surprised that nobody has implemented shrinking yet.
>
> Because it's hard. The only file system I can recall supporting volume
> shrinking is IBM's JFS.

I am pretty sure that ext2/3/4 supports shrinking.

Certainly (V)FAT supports shrinking (although I am certainly not
recommending that).

Shrinking a FS can sometimes be important.  For example, I was working on
a device firmware image and the device they gave me to work with had a
128GB eMMC whereas the "production" devices have a 32G eMMC.  So the
filesystem image I created was for 128G, which meant it couldn't flash
onto a 32G device without shrinking.

So yes, shrinking *IS* important (in some circumstances).

-derek

-- 
       Derek Atkins                 617-623-3745
       derek at ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant