Failed freebsd-update OS upgrade with / now out of space

[kel]

I hope I can recover from this problem. I attempted an upgrade from FreeBSD 8.4 to FreeBSD 10.2 but ran out of disk space mid-way. I received many errors and now the system likely has only a partial new kernel. It's otherwise running fine with normal services and daemons but it's very doubtful I can reboot without it losing its brain. Can I recover from this?

Here are what my disks look like:

Filesystem             Size    Used   Avail Capacity  Mounted on
/dev/da0s1a            495M    483M    -26M   106%    /
devfs                  1.0k    1.0k      0B   100%    /dev
/dev/da0s1e            495M     12k    456M     0%    /tmp
/dev/da0s1f             15G    9.7G    4.8G    67%    /usr
/dev/da0s1d            2.9G    2.3G    355M    87%    /var
/usr/ports              15G    9.7G    4.8G    67%    /usr/jails/webjail/usr/ports
/dev/da1s1d             23G    4.0k     21G     0%    /dd
/dev/da2s1d            445G    4.0k    409G     0%    /backup
/usr/jails/basejail     15G    9.7G    4.8G    67%    /usr/jails/webjail/basejail
devfs                  1.0k    1.0k      0B   100%    /usr/jails/webjail/dev
fdescfs                1.0k    1.0k      0B   100%    /usr/jails/webjail/dev/fd
procfs                 4.0k    4.0k      0B   100%    /usr/jails/webjail/proc

I've thought about some possible options:
(1) Can I resize active partitions with gpart and grow the size of / ?
(2) Can I mount /boot somewhere else that has plenty of space *without* rebooting first, and then attempt the upgrade again?
(3) Can I roll back freebsd-update(8) and somehow put the old kernel back, and then grow the size of / using other space like the unused /dd or /backup?

(4) Or something else? The path to saving this system isn't clear to me. NOTE: I do not have console access, the hardware is in a rack in a datacenter far away so I cannot use single-user mode remotely at the moment.

Any ideas or suggestions?

 

[lme@]

You could start by deleting /boot/kernel*/*.symbols. Then you should have some space on / left to play with. Next you could try a # freebsd-update rollback

 

[kpa]

Re-install with 10.2 or 9.3 after you've solved the out of space problem. The older FreeBSD releases defaulted to only 512MB or so root partition and that is no longer enough to hold the old kernel and the new kernel at the same time.