partitioning schemes: GPT <-> MBR

[Wolfram Schneider]

Hi guys,

I have 2 small virtual machines running in data center, on similar
hardware. Both are running FreeBSD 12-current. The first one is based
on a 10.3 image, upgraded to current. The second one is based on 11.1,
upgraded to current.

I notice a difference in disk partitioning. 10.3 is using GPT, and 11.1 MBR.

[FreeBSD 10.3]
$ gpart show
=> 34 83886013 vtbd0 GPT (40G)
34 1024 1 freebsd-boot (512K)
1058 2097152 2 freebsd-swap (1.0G)
2098210 81787836 3 freebsd-ufs (39G)
83886046 1 - free - (512B)

[FreeBSD 11.1]
$ gpart show
=> 63 83886017 vtbd0 MBR (40G)
63 1 - free - (512B)
64 79691776 1 freebsd [active] (38G)
79691840 4194240 - free - (2.0G)

I thought that MBR is outdated. But the hosting company told me that
FreeBSD 11.1 is using MBR by default. Is that correct?

My problem with the MBR machine is that I cannot add a swap device.
There are 2GB free space, and I want add a 1GB swap device:

$ gpart add -s 1G -t freebsd-swap vtbd0
gpart: Invalid argument

is this an MBR issue?

thanks, Wolfram

[Ian Lepore]

Post by Wolfram Schneider
Hi guys,
I have 2 small virtual machines running in data center, on similar
hardware. Both are running FreeBSD 12-current. The first one is based
on a 10.3 image, upgraded to current. The second one is based on 11.1,
upgraded to current.
I notice a difference in disk partitioning. 10.3 is using GPT, and 11.1 MBR.
[FreeBSD 10.3]
$ gpart show
=>      34  83886013  vtbd0  GPT  (40G)
       34      1024      1  freebsd-boot  (512K)
     1058   2097152      2  freebsd-swap  (1.0G)
  2098210  81787836      3  freebsd-ufs  (39G)
 83886046         1         - free -  (512B)
[FreeBSD 11.1]
$ gpart show
=>      63  83886017  vtbd0  MBR  (40G)
       63         1         - free -  (512B)
       64  79691776      1  freebsd  [active]  (38G)
 79691840   4194240         - free -  (2.0G)
I thought that MBR is outdated. But the hosting company told me that
FreeBSD 11.1 is using MBR by default. Is that correct?
My problem with the MBR machine is that I cannot add a swap device.
$ gpart add -s 1G -t freebsd-swap vtbd0
gpart: Invalid argument
is this an MBR issue?
thanks, Wolfram

You need to add a new freebsd slice, then add the freebsd swap
partition within it:

 gpart add -s 1g -t freebsd vtdb0
 gpart create -s bsd vtdb0s2
 gpart add -t freebsd-swap vtdb0s2

Now you should have a /dev/vtdb0s2b available for swap.  There will
also be ~1g still available to create another slice.

Another alternative is just create the vtdb0s2 slice, then don't
subdivide it into BSD partitions at all, just add /dev/vtdb0s2 to fstab
as a swap device.

-- Ian