Re: debian-installer: Guided partitioning breaks PERC2 Raid controllers
On Wed, 14 Sep 2011, trouble daemon wrote:
> On Wed, Sep 14, 2011 at 8:44 AM, Henrique de Moraes Holschuh
> <hmh@debian.org> wrote:
> > On Mon, 12 Sep 2011, trouble daemon wrote:
> >> So it would seem that the installers guided partitions are creating
> >> broken partition tables that seem to mess with certain RAID
> >
> > No, it is creating perfectly fine LBA partition tables that are aligned to
> > 1MiB boundaries.
>
> Then why was fdisk -l showing me that the boot volume the installer
> created as being not aligned properly, and that went away after I
> manually created it on tty2 with fdisk and popped back to tty1 and
> continued to the partition step and used the existing partition
> layout?
Because you used old fdisk (or new fdisk in dos mode), and it is paying
attention to CHS information.
> > Contact Dell and demand a PERC2 firmware update: it is their crap firmware
> > which is doing something it shouldn't.
>
> Well true, I agree that the firmware is old and has problems in that
> it could more gracefully handle such a situation, but if the table was
> being aligned the same way it does when I manually fdisk it, I don't
> think this would be a problem. In fact, I don't think this was ever a
> problem in the last 10 years I have had it running debian until
> recently.
The world has changed, and left CHS crap behind, as well as the hacks
from hell these older RAID cards did to try to recover performance from
the absurd misalignent issues they had trying to match RAID stripe size
to CHS boundaries.
Nowadays, we have to align to either 4KiB (spinning rust), erase-block
size (crappy SSDs) or RAID stripe size (any RAID). 1MiB works right for
everything but very large RAID stripe sizes.
> > It might be useful to have a "legacy dos-compatible MBR" option on the
> > expert mode, indeed.
>
> Ah, interesting option. Ya, something like that would definetly be
> nice. So if I understand this right then, it's because when I fdisk,
> it uses a dos compatible MBR? Then what in the world is partman (right
> name for sub app?) using? Seemed like it was standard MBR last I
> looked at fdisk -l, and only differed in that only sda1 was out of
> alignement.
>
> Anyways, I appreciate the reply and some of the insight. Look forward
> to hearing back from you. Thanks!
Please file a normal bug, explaining that PERC2 and some other arrays
require DOS-compatible MBRs and asking for an expert mode option to get
that. The package name to report the bug against is "debian-installer".
You can use reportbug to file that bug.
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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