Re: FFSv2ea

[Matthias Petermann <mp%petermann-it.de@localhost>]

Hello Clay,

On 17.01.23 03:27, Clay Daniels wrote:
> I've enjoyed trying out the new 10.0_BETA and I've selected the newer 
> FFSv2ea from the partition menu of the installation a couple of times.
>
> If I try this:    #gpt show wd0
>
> I get this:        GPT part - NetBSD FFSv1/FFSv2
>
> Then the next installation I deliberately used the default of FFSv2, I 
> get the same thing. I'm sure I must be expecting the gpt command to do 
> more than it really does. What other commands shows the fast file system 
> in use?
>
> Clay

the output of gpt corresponds to the GPT partition type. This is rather 
generic in my opinion - you can see that FFSv1 and FFSv2 seem to share a 
code here.

More precise information about the contents of the FFS file system 
internally can provide the command dumpfs. Attention: this only works on 
unmounted partitions. For example, it also shows the subtype FFSV2ea. 
Here is an example:

```
$ doas dumpfs /dev/dk2 | head

file system: /dev/dk2
format  FFSv2ea
endian  little-endian
location 65536  (-b 128)
magic   19012038        time    Mon Jan 16 16:32:12 2023
superblock location     65536   id      [ 63010452 50c5903c ]
nbfree  5327255 ndir    12306   nifree  16432093        nffree  1132
ncg     354     size    67108855        blocks  66069485
bsize   32768   shift   15      mask    0xffff8000
fsize   4096    shift   12      mask    0xfffff000
frag    8       shift   3       fsbtodb 3
bpg     23697   fpg     189576  ipg     46720
minfree 5%      optim   time    maxcontig 2     maxbpg  4096
symlinklen 120  contigsumsize 2
maxfilesize 0x000800800805ffff
nindir  4096    inopb   128
avgfilesize 16384       avgfpdir 64
sblkno  24      cblkno  32      iblkno  40      dblkno  2960
sbsize  4096    cgsize  32768
csaddr  2960    cssize  8192
cgrotor 0       fmod    0       ronly   0       clean   0x01
wapbl version 0x1       location 2      flags 0x0
wapbl loc0 268463360    loc1 131072     loc2 512        loc3 3
usrquota 0      grpquota 0
flags   none
fsmnt   /export
```

However, it is reasonable to ask whether the reasons that led to the 
introduction of the new FFSV2 subtype ea would also require a standalone 
GPT partition type, or whether the current status is still ok, since 
nothing has changed in the basic on disk format of the filesystems. Here 
I do not know however the guidelines. Maybe Chuck can answer that?

Kind regards
Matthias