AIX

The default: stanza in /etc/security/limits is still set to 2097151 on fsize (max file size). I know tar had issues with large files but is there any other reasons for it? I'm thinking yes since it's still set to that by IBM.

Cheers,
DH

Often limits on file size are set so that a file cannot be created which so so large to fill up the file system.

For example, if you did not limit the file size when uploading a file to a web server, a hacker could easily bring done the server by uploading huge files and fill of the file system.. then the server would crash.

I hear you. That's true if it's all on one LV.

In this case, the user account is limited to their LV / FS. So no crash is possible for the OS. With smaller files, hackers can upload repeatedly instead to do the same anyway. Larger files may actually hamper those hack attempts because these same hackers would run into timeout issues from other software like sftp, ftp, ssh, connection speeds / fluctuations etc.

I know tar / cpio have limitations on 2GB, even on AIX 7.1, but what about other utilities?

Cheers,
DH

The AIX tar adheres to the USTAR standard, which in turn means: no single input file processed by tar can be larger than 8 GB, but the archive itself can be of (nearly) unlimited size. The reason for the limitation is the data structure of the USTAR header which can't hold size information of more than 8 GB.

I hope this helps.

bakunin

The pax utility (with the -x pax option to set the archive format) provides extensions to the ustar archive format to remove the ustar format file size limits. When using the pax archive format, any size file can be saved in an archive as long as the archive created will fit into whatever device or filesystem is used to contain the archive.

Some implementations of cpio and tar (as well as the pax utility) are able to create and read pax format archives.