On Wednesday 16 February 2011, Steven R. Gerber wrote:
> Sorry for cross posting?
> I am trying to setup a decent RAID (0+1 or 1+0 or 5) and there SEEMS to
> be no approved method. (4 disks -- I usually like stripe on top of
> mirrors.)
> I believe that I have done my homework.
> What are my options?
>
> softraid (bioctl) cannot handle stripe on mirrors:
> I can easily create 2 mirrors and they survive reboot.
> I can create stripe on those mirrors (works -- can create files), but it
> does not survive reboot.
Define "does not survive reboot". I'm guessing that you probably mean "fails
to automatically reassemble at boot", which is accurate - we do not currently
probe volumes that we have just assembled. Things should just work if you
manually assemble it after the mirrors are available. Note that this is not a
supported configuration, however it does seem to work - YMMV.
> Message is device not configured.
>
> Both ccd and RAIDframe are decprecated (FAQ 14.13):
> > Software Options
> > OpenBSD supports softraid(4), a framework supporting many kinds of I/O
>
> transformations, including RAID and encryption disciplines. Softraid(4)
> is managed using bioctl(8).
>
> > OpenBSD also includes RAIDframe (raid(4), requires a custom kernel),
>
> and ccd(4) as historic ways of implementing RAID, but at this point
> OpenBSD does not suggest implementing either as a RAID solution for new
> installs or reinstalls.
> "OpenBSD does not suggest implementing either"
> Also, RAIDframe requires a custom kernel and we all know that GENERIC is
> preferred.
>
> RAID 5 is experimental (man bioctl):
> > CAVEATS
> > Use of the CRYPTO & RAID 4/5 disciplines are currently considered
> > experimental.
> >
> > OpenBSD 4.9 December 22, 2010
>
> OpenBSD 4.9
>
> Also, bioctl would not let me create a RAID 5 set:
> # bioctl -iv softraid0
> # bioctl -c 5 -l /dev/sd1a,/dev/sd2a,/dev/sd3a,/dev/sd4a softraid0
> bioctl: BIOCCREATERAID: Invalid argument
> # bioctl -iv softraid0
> # dmesg|tail
> sd11 at scsibus6 targ 0 lun 0: <OPENBSD, SR RAID 0, 004> SCSI2 0/direct
> fixed
> sd11: 3815436MB, 512 bytes/sec, 7814014721 sec total
> sd11 detached
> scsibus6 detached
> sd10 detached
> scsibus5 detached
> sd9 detached
> scsibus4 detached
> softraid0: not part of the same volume
> softraid0: can't attach metadata type 0
You previously had a RAID 0 volume on some or all of these partitions, hence
the "not part of the same volume" and "can't attach metadata type 0" messages
(softraid is refusing to make members of a RAID 0 volume into a RAID 5
volume). Either wipe the first 1MB or so of each partition (dd if=/dev/zero
of=/dev/rsd1a bs=1m count=1, etc) or use 'bioctl -C force ... '.
--
b Reason is not automatic. Those who deny it cannot be conquered by it.
Do not count on them. Leave them alone.b -- Ayn Rand
