root@mowa219-gjp4-8570p-freebsd:~ # bectl list -c creation
BE                     Active Mountpoint Space Created
n260316-9922bccbc9c4-d -      -          258M  2023-02-03 23:45
n260316-9922bccbc9c4-e -      -          6.46M 2023-02-06 16:25
n260316-9922bccbc9c4-f -      -          5.02G 2023-02-10 08:12
n261014-cd406ac94d8b-a -      -          149M  2023-02-19 02:16
n261014-cd406ac94d8b-b -      -          83.0M 2023-02-19 09:15
n261014-cd406ac94d8b-c -      -          180M  2023-02-20 23:46
n261014-cd406ac94d8b-d -      -          355M  2023-02-22 17:55
n261014-cd406ac94d8b-e -      -          54.9M 2023-02-25 11:44
n261014-cd406ac94d8b-f NR     /          338G  2023-02-26 15:56
root@mowa219-gjp4-8570p-freebsd:~ # pkg clean -a
The following package files will be deleted:
        /var/cache/pkg/munge-0.5.14_1~c01d2be3f5.pkg
        /var/cache/pkg/munge-0.5.14_1.pkg
The cleanup will free 129 KiB

Proceed with cleaning the cache? [y/N]: y
Deleting files: 100%
All done
root@mowa219-gjp4-8570p-freebsd:~ # bectl create n261014-cd406ac94d8b-g
root@mowa219-gjp4-8570p-freebsd:~ # bectl mount n261014-cd406ac94d8b-g /tmp/up
Successfully mounted n261014-cd406ac94d8b-g at /tmp/up
root@mowa219-gjp4-8570p-freebsd:~ # pkg -r /tmp/up upgrade
…
root@mowa219-gjp4-8570p-freebsd:~ # bectl umount n261014-cd406ac94d8b-g 
root@mowa219-gjp4-8570p-freebsd:~ # bectl activate n261014-cd406ac94d8b-g