Re: [Libguestfs] [PATCH virt-v2v] v2v: Allow temporary directory to be set on a global basis.

On Thursday, 2 April 2020 14:49:18 CEST Richard W.M. Jones wrote: I do not understand the motivation behind this, which adds yet another location with temporary files in addition to: - LIBGUESTFS_TMPDIR - $TMPDIR by default (which itself is /tmp by default) - LIBGUESTFS_CACHEDIR - /var/tmp by default (with a .guestfs-$UID subdirectory for the appliance) Before this patch, almost all the temporary files are stored directly or in subdirectories of $TMPDIR, except big files such as overlays and OVA extracted content that are in CACHEDIR. With the proposed changes, _all_ the temporary files will be in CACHEDIR, so there are the following problems: - this directory will be cluttered with a lot more files than before - if it is shared, then other places where it is mounted will see the same files - if it is shared, then creating temporary files will possibly mean doing network I/O - if virt-v2v exits uncleantly, there will be a lot more files to cleanup than now - even without being shared, /var/tmp is persistent unlike /tmp (which can be tmpfs-backed on some distros/setups), meaning old temporary files will linger way more That said, it is not clear to me why /var/tmp should be shared among containers. Regardless of this patch, this bit is not correct: - libguestfs does not places large files in $TMPDIR (but in CACHEDIR) - $TMPDIR is not /var/tmp by default, but /tmp -- Pino Toscano