Re: Filesystem and free space

[Tom Dial <tddial@comcast.net>]

On 12/12/21 12:28, Teemu Likonen wrote:
> * 2021-12-12 14:13:19-0500, Polyna-Maude Racicot-Summerside wrote:
> 
>> How can I ensure that user (or a software being run by a user that
>> goes crazy) doesn't fill up the whole filesystem ?
> Commands mkfs.ext4 and tune2fs have this option:
> 
>     -m reserved-blocks-percentage
>            Set the percentage of the filesystem which may only be
>            allocated by privileged processes. Reserving some number of
>            filesystem blocks for use by privileged processes is done to
>            avoid filesystem fragmentation, and to allow system daemons,
>            such as syslogd(8), to continue to function correctly after
>            non-privileged processes are prevented from writing to the
>            filesystem. Normally, the default percentage of reserved
>            blocks is 5%.
> 
> See the last sentence. By default normal users can't fill the entire
> space. Use tune2fs to change options for an existing file system.

In addition, per user and per group file system quotas have been available in Unix and Linux for as long as I can remember. For Debian, see https://debian-handbook.info/browse/stable/sect.quotas.html. Man pages for mkfs.ext4, tune2fs, and edquota (and probably others) have additional relevant information. 

Regards,
Tom Dial

> 
> -- /// Teemu Likonen - .-.. https://www.iki.fi/tlikonen/ // OpenPGP: 6965F03973F0D4CA22B9410F0F2CAE0E07608462