On Tue, 5 Sep 2000, Manuel Bouyer wrote:

> I think you could also use RAIDFrame for this (see raid(4)).
> But if you plan to use raid 1 for something serious I would recommend
> 1.5_ALPHA instead. ccd is'nt gread at mirroring (it can't recover without
> external intervention when a disk dies), and several problems with RAIDFrame
> have been corrected since 1.4.2.

Yes, I think I shall wait for NetBSD-1.5.  BTW, I tried using raid myself
on NetBSD-1.4.2 -- but I was confused abt "arrays" and "rows" and
"columns" etc. which I was supposed to fill up in the configuration file.
I had two primary partitions of 4 MB each (made just for this purpose) --
which were wd0g and wd0h, and so I gave the number of rows as 1, nor of
columns as 2 (after reading the manpage), and RAID 1, and tried
configuring it.  But, the kernel just gave a whole screenful of error
messages (abt the columns and rows being wrong or something like that).  I
left it after that.

But, I went through an bsdtoday article pointed out to me by a
fellow-poster, and in that it says I should first mark the partitions I
want to use for RAID1 as "RAID."  I haven't checked up to see it it works,
but if that's how we are to do things, how come the manpage doesn't
mention it. (Coz as far as I think, the steps I took and what the article
says are ditto except on this point).  I hope you would advise me on this
point.

I can pass along the errors that I got (if syslogd has recorded it), and
also my config files if you need.

> > And another doubt: suppose I use wd0e and wd1e as mirrors -- then, is it
> > possible that I can access the data of wd0e separately ?  That is, if I
> > make ccd0 with mirror options using wd0e and wd1e; can I mount wd0e alone
> > read-only (so that I won't put the mirrors out of sync)  and access the
> > data in it ?
> 
> It should be possible, but you need to declare a new partition. ccd
> reserves some place for its own stuff at the beggining of the disk.
> The best way of doing this would be to use a ccd with only one componnent.

Err, I think I made a mistake.  Does ccd support mirroring ?  ccd for
OpenBSD has this option in its manpage; ccd for NetBSD-1.4.2 does not.
I guess my question should have been abt RAID 1, instead of ccd.  But
still, I am not clear as to what you have suggested. What do you mean
declare a new partition ?  Make a disklabel entry for it, or what ... ?

Phew!  I guess that's a lot of questions I have asked in one mail.  

TIA.
Rakhesh