The resize guard reads the Used column for /dev/zram0 out of /proc/swaps
and treats a missing row as an empty device, which is right for a device
that doesn't exist yet: the restart is what brings it up against the
config daemon-reload just generated. A device that exists and is merely
swapped off reads the same, and there the restart resets it first, which
returns EBUSY for as long as anything still holds it open. That leaves a
bare "Job failed. See 'journalctl -xe' for details." in the migration
output and falls through to asking for the reboot that would have
resized it anyway.
Tell the two apart by whether /sys/block/zram0/disksize is there at all.
The test modelled an absent device as a blank disksize file, which no
longer stands in for one, so it removes the file instead.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
zram-size = min(ram, 8192) is Fedora's default since F34, where
zram-fraction=1.0 with max-zram-size=8192 has run on desktops for five
years. The previous min(ram / 2, 8192) halved that on every machine
below 16G with nothing behind the fraction; at 16G and above the two
already agree.
A changed size only reaches a running device on the next boot, so the
migration resizes an empty device now and asks for a reboot otherwise.
It asks the generator what the config evaluates to rather than
repeating the expression here, and does neither when the device already
matches.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
