Re: boot disk has two MBR partitions

[Saifi Khan <saifi.khan%fastpath.in@localhost>]

On Fri, 1 Mar 2013, David Lord wrote:

> I's rare for me to need to use fsck. After a crash requiring
> reboot I see entries in /var/log/messages:
>   "/netbsd: /: replaying log to disk"
>
> Were your partitions created manually?

Yes, i created the partitions manually.


> Currently my systems have ffsv2 partitions either auto created
> at install, using "newfs -O", or by using "ffsk_ffs -c 4" for
> existing partitions.

On both the MBR partitions, the default file-system format 
is 'FFSv1'.

Having said that, i picked up a clue from the option 
you chose in second command ie. 'fsck_ffs -c 4'.

The man page for fsck_ffs details the option '-c' as

  ...
  disable the rotational layout tables
  and per cylinder group block totals.
  ...

Perhaps this is done in order to gain performance.

This kind of hints to my query that does fsck perfmance get 
impacted due to mapping issues. But, i'm not sure.


> /etc/fstab entries have the "log" option, eg.
> /dev/wd0a    /     ffs   rw,log    1  1
> /dev/wd0h    /var  ffs   rw,log    1  2

There is no "log" option in the /etc/fstab file on laptop.

Thanks for the expository discussion.


thanks
Saifi.