[coreboot] 2 Terabyte Limit of BIOS/MBR
martin at marcher.name
Sat Jan 12 20:20:13 CET 2008
On Thursday 10 January 2008 22:55 Carl-Daniel Hailfinger wrote:
> On 10.01.2008 21:59, Martin Marcher wrote:
>> hope to be in the right place to ask this, if not just point me to where
>> you think it's apropriate
>> my Hardware is:
>> Tyan Transport GT20 (B2865)
>> an Areca 1210 raid controller is attached to it and I just was hit by the
>> 2TB limit which a BIOS can handle.
> Is the RAID array exactly 2 TB? Then the BIOS will see its size as 0.
nope it's 3TB total. Running debian/etch
we have seperate /boot / partitions and most of the space is used by some
xen domUs. / is inside an LVM (guess that doesn't matter a lot since debian
itself is ready for the large block device support)
> Why should we replicate such a bug? If you use Linux as bootloader
> inside LinuxBIOS and if the Linux kernel has support for devices >2 TB
> enabled (all recent kernels do), you can boot from disks up to 65535 TB
> (maybe even 131071 TB) if the adapter creates a virtual SATA device (the
> limits are what you would expect from LBA48 addressing). Depending on
> the device driver (you said the RAID adapter claims to be SCSI), the
> limit may be even higher.
the problem is I don't get to boot linux. Tried to boot from a cd with only
grub on it but after some reading I concluded that grub relies on the disks
reported from the bios. All grub finds is (cd) and fd0-9 - not a single hd
> Three "solutions":
> 1. Use LinuxBIOS and Linux as Bootloader (LAB)
> 2. Use the vendor BIOS and boot from a smaller disk
I do that right now, but I consider it a not optimal solution
> 3. Use the vendor BIOS, but make sure the RAID is either smaller than 2
> TB or a few GB bigger than 2 TB (in that case the detected size would
> probably be real size minus 2 TB). To be honest, this tip may or may not
> work, depending on how broken the BIOS is.
well it's not working since the disk is "stuck" at >2TB (750GB are used the
rest is free, but the raid controller doesn't have an option to shrink it
>> 3) Last, not least I couldn't the Tyan GT20 in the supported hardware
>> list, is that true or just missing.
> True. It should be supportable, though, if we have one board to
> experiment with. The Tyan Tomcat K8E S2865 is the board inside according
> to the manual.
>> If it's missing I'll bug Tyan about this once a month or so, in case you
>> don't have the specs available to send it to you (if you want me to do
> How much time are you willing to invest to port LinuxBIOS to the board?
If it was only me: as much as needed
We are a small company with 2 physical server but given I could find a setup
where I can install and uninstall linuxbios securely (in case it won't
work) I guess I could talk my boss into allowing me to regularly taking the
server down and test the bios - reading up on this in the wiki now
You are not free to read this message,
by doing so, you have violated my licence
and are required to urinate publicly. Thank you.
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