> On Fri, Jun 1, 2012, at 03:27 PM, Nick Holland wrote:
> > Otto gave you a good answer here, but I had already provided lots of 
> > detail, so I'm sending anyway. :)
> > 
> > On 06/01/2012 01:04 PM, Scott McEachern wrote:
> > > Hello everyone,
> > >
> > > I'm hoping that I'm missing something simple (like usual) and maybe
> > > someone could straighten me out.
> > >
> > > I'm trying to add a pair of 3TB drives to my workstation, which I plan
> > > on turning into a ~3TB RAID 1 array, and seem to be having difficulty
> > > realizing the full size of the drives.
> > >
> > > The hardware is about a year old, and less than two years old according
> > > to the BIOS date:
> > >
> > > bios0: vendor American Megatrends Inc. version "2103" date 06/18/2010
> > > bios0: ASUSTeK Computer INC. M4A785TD-V EVO
> > >
> > > (Correction, I've since updated the BIOS to the latest version, just in
> > > case, and it reads like so:
> > >
> > > bios0: vendor American Megatrends Inc. version "2105" date 07/23/2010
> > >
> > > and it makes no difference.)
> > >
> > > (The full dmesg is below, but for now I'll just post the relevant bits.)
> > >
> > > The BIOS happily reports the two drives as present and of 3.0TB
> > > capacity. OpenBSD seems to recognize this as well:
> > >
> > > sd0 at scsibus0 targ 0 lun 0: <ATA, WDC WD5000AAKS-0, 05.0> SCSI3
> > > 0/direct fixed naa.50014ee001cbd923
> > > sd0: 476940MB, 512 bytes/sector, 976773168 sectors
> > > sd1 at scsibus0 targ 1 lun 0: <ATA, ST3000DM001-9YN1, CC4B> SCSI3
> > > 0/direct fixed naa.5000c5004a6e56f1
> > > sd1: 2861588MB, 512 bytes/sector, 5860533168 sectors
> > > sd2 at scsibus0 targ 2 lun 0: <ATA, ST3000DM001-9YN1, CC4B> SCSI3
> > > 0/direct fixed naa.5000c5004a5baa2e
> > > sd2: 2861588MB, 512 bytes/sector, 5860533168 sectors
> > 
> > Life is good.
> > 
> > ...
> > 
> > > I just wanted to get on with my day and not have any fuss, so I issued
> > > an "fdisk -iy sd1" command on the way to disklabel'ing things. I suspect
> > > that's my error, because fdisk says this: (I've added some commas to
> > > make for easier reading.)
> > >
> > > # fdisk sd1
> > > Disk: sd1 geometry: 364801/255/63 [1,565,565,872 Sectors]
> > > Offset: 0 Signature: 0xAA55
> > > Starting Ending LBA Info:
> > > #: id C H S - C H S [ start: size ]
> > > -------------------------------------------------------------------------------
> > >
> > > 0: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
> > > 1: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
> > > 2: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused
> > > *3: A6 0 1 2 - 97451 165 59 [ 64: 1,565,560,705 ] OpenBSD
> > >
> > > Uhm, that doesn't seem right
> > 
> > well. it's annoying, but "rightish". :)
> > fdisk edits MBRs, MBR has a limit of 2TB on its structures.
> > So...it looks like fdisk basically did a 3TB modulo 2TB.  I really 
> > should save myself looking like a fool and check my math, but if I'm 
> > wrong, it will teach you not to take what I say as gospel :)
> > 
> > Some OSs want you to switch to a new way of handling big disks, but I do 
> > think OpenBSD will do what you want "natively".
> > 
> > ..
> > > A drive with half the capacity seems to have double the numbers, but not
> > > for geometry. I suspect that fdisk is lying to me, but I could be wrong.
> > 
> > you are right.
> > 
> > > Let's see what disklabel(8) has to say. On the 1.5TB drive, it looks
> > > mostly like this (I've snipped some irrelevant partition data and added
> > > commas to make big numbers easier to read):
> > ..
> > > total sectors: 2,930,277,168
> > > boundstart: 64
> > > boundend: 2930272065
> > > drivedata: 0
> > >
> > > 16 partitions: (snipped)
> > > # size offset fstype [fsize bsize cpg]
> > > c: 2,930,277,168 0 unused
> > >
> > > On the new 3TB drive, it looks like this:
> > >
> > > # disklabel sd1
> > ..
> > > total sectors: 5,860,533,168
> > > boundstart: 64
> > > boundend: 1565560769
> > > drivedata: 0
> > >
> > > 16 partitions:
> > > # size offset fstype [fsize bsize cpg]
> > > c: 5,860,533,168 0 unused
> > >
> > > Wait a minute here... disklabel seems to have correct data (ignoring the
> > > duid). I'll bet I'm failing at grade four math, but that looks roughly
> > > like a 3TB drive.
> > 
> > yes, it's a 3TB disk, but at the moment, disklabel is restricting you to 
> > just the fdisk-marked part of the drive...which is as it should be.  You 
> > generally don't want your OpenBSD partitions living outside the OpenBSD 
> > MBR (fdisk) partition.
> >    EXCEPT when the MBR isn't providing useful info.  Like now.
> > 
> > ...
> > > At this point I'm wondering WTF is going on. Is this an OpenBSD-specific
> > > problem? A BIOS issue? So I unplug all drives except one of the 3TB's,
> > > install FreeBSD and tell it to use the whole drive. I get the exact same
> > > results from their disklabel. Must be the hardware, right?
> > 
> > What you want to do is use the 'b' option of disklabel to redefine the 
> > OpenBSD boundaries of the disk.  I do believe it will let you specify 
> > the whole disk, and you can then do what you want.
> > 
> > A few words of warning...
> > 
> > * This really messes up your ability to multiboot, as non-OpenBSD OSs 
> > will think anything beyond the fdisk/MBR partition might be available. 
> > But then, most other OSs choke pretty badly at this point anyway.  may 
> > not be that big a problem.
> > * Lots of BIOSes that see >128G disks still won't let you boot from 
> > partitions higher than 128G.
> > * I haven't actually TRIED this.  I was planning on buying a 3TB disk to 
> > experiment on and update FAQ14...but just before I did, there was this 
> > little flood issue, and being a cheapskate, I didn't want to sink a lot 
> > of money into a drive I didn't really need quite yet (or more 
> > accurately, I need TWO of...)
> > * Rebuilding the mirror will be a beast.
> > * you don't want to fsck a 3TB file system, 'specially if it is 
> > rebuilding the mirror at the same time, though with 12G RAM, you might 
> > be able to do it.
> > 
> > Nick.
> > 
> 
> Looks like Nick and OBSD could use a Donation.
> Anyone here in the community willing to step up
> and donate a couple 3TB drives?
> I would if I could so I understand if some people can't,
> but I'm sure there are a few people out there.
> 

I have two older Western Digital WD30EZRSDTL drives I can part with.

Jason,
ber...@bergie.net

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