Re: 5.0 and raid1 - kernel dump clarification

[Greg Oster <oster%cs.usask.ca@localhost>]

Carl Brewer writes:
> Greg Oster wrote:
> 
> > That is correct.  (perhaps the wording should be adjusted to make 
> > that more clear...)
> 
> 
> Thanks Greg, my last query is the working of fstab for this, the guide, 
> at least to me, is unclear here (s16.3.8 of the guide) :
> 
> Note that for NetBSD releases prior to 5.0 the kernel crash dumps must 
> not be saved on a RAID device but on a real physical disk (wd0b). This 
> dump area was created in the previous chapter on the second disk (wd1b) 
> but we will make wd0 an identical copy of wd1 later so wd0b and wd1b 
> will have the same size and offset. If wd0 fails and is removed from the 
> server wd1 becomes wd0 after reboot and crash dumps will still work as 
> we are using wd0b in /etc/fstab. The only fault in this configuration is 
> when the original, failed wd0 is replaces by a new drive and we haven't 
> initialized it yet with fdisk and disklabel. In this short period of 
> time we can not make crash dumps in case of kernel panic. Note how the 
> dump device has the ?dp? keyword on the 4th field.
> 
> # vi /mnt/etc/fstab
> 
> /dev/raid0a  /  ffs  rw  1  1
> /dev/raid0b  none  swap  sw  0  0
> /dev/wd0b  none  swap  dp  0  0
> kernfs    /kern  kernfs  rw
> procfs    /proc  procfs  rw
> 
> 
> 
> My question, with 5.0+, where does the 'dp' go, if anywhere?

You don't need a special 'dp' line -- it will automatically dump to 
raid0b and do the right things... 

> My fstab :
> 
> # NetBSD /etc/fstab
> # See /usr/share/examples/fstab/ for more examples.
> #/dev/wd0a              /       ffs     rw               1 1
> /dev/raid0a             /       ffs     rw               1 1
> #/dev/wd0b              none    swap    sw               0 0
> /dev/raid0b             none    swap    sw               0 0
> kernfs          /kern   kernfs  rw
> ptyfs           /dev/pts        ptyfs   rw
> procfs          /proc   procfs  rw
> /dev/cd0a               /cdrom  cd9660  ro,noauto
> 
> Is there a need with 5.0+ to define wd0b in fstab as a swap partition 
> and a kernel dump site (and the mystery dp)? 

No.

> What should this look like? 

You just need the generic "swap is on raid0b" line:

 /dev/raid0b             none    swap    sw               0 0

and dumps will automatically go to there.

> I'm happy to write an update to the guide on this, but not 'til I 
> know the right way to do it!
> 
> thanks again
> 
> Carl
> 
> 
> 

Later...

Greg Oster