Is there a file system out there that supports custom file size limit ?

stoorky · 02-11-2021, 08:33 AM

Hi,
I'm aware that EXT4 has a

Code:

max_dir_size_kb

mount option to set up the max size of each directory. It doesn't have a similar option to specify the max size of individual files, though.

Is somebody aware of another file system that could do this ? I checked XFS, ZFS and ReiserFS, but didn't find anything, though I'm no expert on those file systems.

To be more specific about what I try to achieve : I'd like to limit the size of individual files that can be stored on a Samba share (individual files, not global quota, e.g. prevent users from storing files exceeding a given size). Samba doesn't have an option for this, and the Linux /etc/security/limits.conf doesn't work either with Samba (see https://askubuntu.com/questions/1315...4-ubuntu-20-04, and the answer below : the Samba developers explained that file size limits set up in /etc/security/limits.conf are not enforced).

So my idea was to define that limit on the file system level, but it doesn't appear there is a file system supporting this feature.

wpeckham · 02-11-2021, 07:03 PM

Quote:

Originally Posted by stoorky

Hi,
I'm aware that EXT4 has a

Code:

max_dir_size_kb

mount option to set up the max size of each directory. It doesn't have a similar option to specify the max size of individual files, though.

Is somebody aware of another file system that could do this ? I checked XFS, ZFS and ReiserFS, but didn't find anything, though I'm no expert on those file systems.

To be more specific about what I try to achieve : I'd like to limit the size of individual files that can be stored on a Samba share (individual files, not global quota, e.g. prevent users from storing files exceeding a given size). Samba doesn't have an option for this, and the Linux /etc/security/limits.conf doesn't work either with Samba (see https://askubuntu.com/questions/1315...4-ubuntu-20-04, and the answer below : the Samba developers explained that file size limits set up in /etc/security/limits.conf are not enforced).

So my idea was to define that limit on the file system level, but it doesn't appear there is a file system supporting this feature.

Have you researched the QUOTA system? I have never attempted to apply it to a SAMBA share, but it may have application here.

stoorky · 02-12-2021, 02:48 AM

Quote:

Originally Posted by wpeckham

Have you researched the QUOTA system? I have never attempted to apply it to a SAMBA share, but it may have application here.

Quotas are for global restrictions, per share, but don't allow to limit the size of each file

lvm_ · 02-12-2021, 03:34 AM

Don't know about such filesystems but user file size restrictions can be set either via ulimit from shell or more restrictively via pam_limits in limits.conf. Hope that helps.

pan64 · 02-12-2021, 04:36 AM

It looks like there is no direct way (long time ago):
https://unix.stackexchange.com/quest...d-on-file-size

syg00 · 02-12-2021, 05:12 AM

Maybe attack it from the other end - watch the mount-point and delete any big files (after the event). Definite kludge, but should work - doesn't help if you have real constraints in the network bandwidth or actual disk shortages.

jefro · 02-12-2021, 03:04 PM

I pondered this question a bit yesterday.

Most file systems are made to get most out of it. Making it less is contrary to design. However as noted some controls could be in place for things like quota or size of share or such.

The question remains if one could modify a file system with source code to add in a specifed limit. I think so but you may have to do something like iscsi on nas. Samba will kill it otherwise. Might be possible to use NFS.

The problem is that a smart cookie could split up some large file and escape this restriction.

Best just to limit total quota. Let them beg for more.

chrism01 · 02-22-2021, 01:23 AM

Quotas can be set per user - at least on Linux disk. Never tried it on a Samba share, but if the underlying disk is Linux, it should work - I think.