This doesn’t seem to work.
I resized a volume from 1 GB to 3, flyctl volumes list reports the size as 3GB, trying to re-run the extend says Error failed to extend volume: Invalid volume size - Specified volume size must be greater than 3 so Fly really thinks it is 3 GB.
However, inside the restarted VM I still get
/ # dmesg | grep vdc | head -1
[ 0.060596] virtio_blk virtio2: [vdc] 2088960 512-byte logical blocks (1.07 GB/1020 MiB)
/ # df -h /blah
Filesystem Size Used Available Use% Mounted on
/dev/vdc 988.0M 902.5M 18.4M 98% /blah
The kernel sees a block device of only 1 GB:
/ # cat /sys/block/vdc/size
2088960
/ # resize2fs /dev/vdc
resize2fs 1.46.2 (28-Feb-2021)
The filesystem is already 261120 (4k) blocks long. Nothing to do!
The volume in question is vol_53q80vdewqk4gzy6.