On Wed, May 2, 2018 at 9:25 AM, Eric Sandeen sandeen@redhat.com wrote:
On 5/2/18 7:15 AM, Neal Gompa wrote:
On Wed, May 2, 2018 at 5:36 AM Marius Vollmer marius.vollmer@redhat.com wrote:
Neal Gompa ngompa13@gmail.com writes:
And there's still the fun restriction of XFS not being able to shrink.
But note that even ext4 can't shrink while being mounted.
But it can shrink when it's not. This is incredibly important for being able to deal with resizing both / and /home at the same time, or even trying to make space for multi-booting (typically with Windows but some people do other OSes too).
I've always seen the need for shrink as an indicator that someone had poor planning along the way, or insufficient tools for provisioning to start with. Sure, there are exceptions, but in general who needs shrink on a regular basis?
I've used it several times in the last year, usually to re-arrange storage so that a cache is on a separate filesystem and less likely to screw up the whole working environment.
Shrink is actually pretty damaging to the filesystem; it takes all the locality that the allocator tried to provide, and scatters it to the wind. The result is a stitched-together mess.
Locality is *much* less critical with modern flash drives.
Not only that, but wouldn't any sane administrator with important data to take care of make a backup before an invasive action like shrink?
Yes, they would. So what? While it's common to stop a filesystem, backup a directory, and re-assign a new partition mounted locally to restore the data to, this can be a *very* painful operation.
And if you have a backup, you're halfway to mkfs & restore, which will leave you in a much better place.
In theory, yes, which is why I personally prefer to use such tools. But doing this to "/" when someone has used default partitioning and you need to clean it up later with minimal downtime is very expensive in manpower.
So yes, you can shrink ext4, but it really should be seen as a last resort IMHO. I know it can be expedient at times, but I'm not sure people really consider the downsides of the action. On the surface, "yay it's smaller now!" but a bit more investigation shows that it's a de-optimizing, potentially dangerous administrative action. Just my $0.02.
-Eric _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-leave@lists.fedoraproject.org