Attended System Upgrade, x86 VM, error: ext4_allocate_best_fit_partial: failed to allocate 2051 blocks, out of space?

[nmpu]

Current VM disk has the following partitions:

Disk /dev/sda: 512 MiB, 536870912 bytes, 1048576 sectors
Disk model: QEMU HARDDISK
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x80cdd189

Device     Boot Start     End Sectors   Size Id Type
/dev/sda1  *      512   33279   32768    16M 83 Linux
/dev/sda2       33792 1048575 1014784 495.5M 83 Linux

OpenWrt log