On Jan 23, 2008 2:19 PM, John Baldwin [EMAIL PROTECTED] wrote:
On Sunday 20 January 2008 01:53:30 pm David Wood wrote:
Hi there,
In message [EMAIL PROTECTED], Erik
Trulsson [EMAIL PROTECTED] writes
On Sun, Jan 20, 2008 at 04:48:56PM +, David Wood wrote:
In message [EMAIL PROTECTED]
,
Aldas Nabazas [EMAIL PROTECTED] writes
We bought a new Dell PowerEdge 2950III with Perc 6/i and have the
disk
geometry problem using 6.3 final or 7.0 RC1. Seems that we are not
alone at
least one guy has similar problem reported earlier:
http://unix.derkeiler.com/Mailing-Lists/FreeBSD/questions/2008-01/msg0
0506.html
I do not know if the mfi(4) driver has any problems with large disks,
but it
is however well known that fdisk(8) and bsdlabel(8) (the tools normally
used
to partition disks) have problems with volumes larger than 2TB.
If you want to use volumes larger than 2TB then gpt(8) is the
recommended
way to partition the disks. It is however doubtful if the BIOS in your
system will allow you to boot from a gpt(8) parttioned volume which is
best solved with having a separate - smaller - boot volume where the OS
itself is installed.
Erik's reminder is timely for those with 2TB volumes.
You must use gpt and not fdisk on any disk, be it a single drive (in the
future, at least!) or a virtual disk on a RAID setup that are bigger
than 2TB. It may be wise to use gpt on any virtual disk that you might
grow to 2TB or larger in the future, so long as you're not needing to
boot from that virtual disk.
fdisk will not work properly with 2TB and larger volumes - the MBR /
partition table setup can't cope with these large volumes.
You can't boot from a GPT volume - that's a limitation of the BIOS
architecture. There is some thought about using EFI on x64 hardware in
the future (EFI is used on ia64 hardware; GPT is part of EFI), but we're
not there yet. This isn't just about adding GPT support to the BIOS -
the whole BIOS setup is wedded to MBR.
If you need to boot from a 2TB array, create two virtual disks - one
smaller than 2TB to boot from (and use MBR on that), then the residue
can be GPT.
Actually, using gptboot in HEAD you can now boot from GPT on large volumes
(I've booted from a 2 TB volume on a PERC5 using mfi(4) with it). I
will see about getting that merged back to 6.x and 7.x in CVS. We use
it for large volumes on 6.x and all volumes on 7.x at work.
When I said there was nothing relevant waiting for MFC, I was aware of
the change that Tom mentioned, but that seems to be about Dell PERC 6
being identified as such rather than a MegaRAID. It doesn't seem that it
will change the behaviour of the driver in any way.
In our testing at work the 2950 rev 3's worked fine with mfi(4).
--
John Baldwin
Hi John,
Nice to hear that.
Regards,
Aldas
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