To go on from there, I found that my NetBSD VM's only disk was too small to do anything useful. Options for enlarging that came to mind:

1. NFS - see 'panic' above, no go.
2. Adding another (virtual) disk - easily doable, but I felt like not adding one
3. Extending the existing disk - adventure time!

1. Enlarge the last file system on disk
2. Fix the partition table to add another partition for the new space

For those in a similar situation, here are the steps to use the newly gained space on an enlarged (virtual) disk:

1. Prepare: save the old output of "dmesg" (/var/run/dmesg.boot is OK)

2. Enlarge - VMware Fusion wants a shutdown for that, you cannot suspend the machine

3. After booting, run a diff on the saved "dmesg" output, to learn what the old and new size of the disk is, in sectors. My diff looks like this, note the size change in sectors:

   -wd0: 10240 MB, 22192 cyl, 15 head, 63 sec, 512 bytes/sect x 20971520 sectors
   +wd0: 20480 MB, 44384 cyl, 15 head, 63 sec, 512 bytes/sect x 41943040 sectors 

4. Backup the existing/old disklabel, just in case: disklabel wd0 >disklabel.BAK

5. Edit the disklabel: disklabel -e wd0

6. In the editor, adjust the disk size in sectors from 20971520 to 41943040:

   total sectors: 41943040 

7. Partition 'd' is the full disk on i386/amd64, it starts at sector 0 and is 41943040 sectors big

   #        size    offset     fstype [fsize bsize cpg/sgs]
    d:  41943040         0     unused      0     0        # (Cyl.      0 -  44384*)
   

8. Partition 'c' is the NetBSD part of the disk. As this VM only has NetBSD, all the usable space is used. Note that "usable" space excludes the first 63 sectors of the disk (mbr etc.), i.e. it is 41943040 - 63 = 41942977 sectors:

   #        size    offset     fstype [fsize bsize cpg/sgs]
    c:  41942977        63     unused      0     0        # (Cyl.      0*-  44384*)
   

9. After this everything is in sync with the new disk again, and the remaining/new space can be used for new partition 'e'. As the new space starts where the disk used to end, its offset is the old size, 20971520 sectors.

   The size of the new partition expands from the offset sector 20971520 to the end of the disk at sector 41943040, i.e. the partition size is:

   % expr 41943040 - 20971520
   20971520
   

   In total, this gives for the new partition:

   #        size    offset     fstype [fsize bsize cpg/sgs]
    e:  20971520  20971520     4.2BSD   2048 16384     0  # (Cyl.  22192*-  44384*)
   

10. Last, create file system, mount and populate:

    # newfs /dev/rwd0e
    # mkdir /disk2
    # echo '/dev/wd0e /disk2 ffs rw,log 2 2' >>/etc/fstab
    # mount /disk2
    # cd /usr ; pax -rw -pe -v stuff /disk2
    # rm -fr stuff ; ln -s /disk2/stuff .
    

P.S.: I'm offering choccolate to anyone fixing crossbuilding of NetBSD-current from Mac OS X. Any takers?

[Tags: disklabel, fusion, g4u, vmware]