As Peter Wemm wrote:
> Yes, that is much safer, however there are certain bioses that have
> interesting quirks that the MBR has to work around. The problem
> when overlapping mbr and boot1 into the same block is that we no
> longer have the space to do that. boot1.s has got *3* bytes free.
To
On Mon, Dec 10, 2001 at 10:49:28AM -0800, Matthew Dillon wrote:
>
> :For RAID3 that is true. For the other ones...
> :
> :> performance without it - for reading OR writing. It doesn't matter
> :> so much for RAID{1,10}, but it matters a whole lot for something like
> :> RAID-5 wher
On Monday, 10 December 2001 at 9:11:03 +0100, Joerg Wunsch wrote:
> Also, i think that:
>
> uriah /boot/kernel/kernel: da0: invalid primary partition table: Dangerously
>Dedicated (ignored)
> uriah last message repeated 5 times
>
> ...73 of those silly messages are just beyond any form of usefu
Ian Dowse wrote:
> In message <[EMAIL PROTECTED]>, Peter Wemm writ
es
> :
> >The problem is, that you **are** using fdisk tables, you have no choice.
> >DD mode included a *broken* fdisk table that specified an illegal geometry.
> ...
> >This is why it is called dangerous.
>
> BTW, I presume
On 09-Dec-01 Joerg Wunsch wrote:
> As Peter Wemm wrote:
>
>> There shouldn't *be* bootblocks on non-boot disks.
>>
>> dd if=/dev/zero of=/dev/da$n count=1
>>
>> Dont use "disklabel -B -rw da$n auto". Use "disklabel -rw da$n auto".
>
> All my disks have bootblocks and (spare) boot partitions.
:> Well, for reads a non-stripe-crossing op would still work reasonably
:> well. But for writes less then full-stripe operations without
:> spindle sync are going to be terrible due to the read-before-write
:> requirement (to calculate parity). The disk cache is useless in that
> Well, for reads a non-stripe-crossing op would still work reasonably
> well. But for writes less then full-stripe operations without
> spindle sync are going to be terrible due to the read-before-write
> requirement (to calculate parity). The disk cache is useless in that
>
:For RAID3 that is true. For the other ones...
:
:> performance without it - for reading OR writing. It doesn't matter
:> so much for RAID{1,10}, but it matters a whole lot for something like
:> RAID-5 where the difference between a spindle-synced read or write
:> and a non-spi
:> performance without it - for reading OR writing. It doesn't matter
:> so much for RAID{1,10}, but it matters a whole lot for something like
:> RAID-5 where the difference between a spindle-synced read or write
:> and a non-spindle-synched read or write can be upwards of 35%.
On Mon, Dec 10, 2001 at 10:13:20AM -0800, Matthew Dillon wrote:
> :Spindle sync is an anachronism these days; asynchronous behaviour
> :(write-behind in particular) is all the rage. You'd be hard-pressed to
> :find drives that even support it anymore.
>
> Woa! Say what? I think you are t
:Spindle sync is an anachronism these days; asynchronous behaviour
:(write-behind in particular) is all the rage. You'd be hard-pressed to
:find drives that even support it anymore.
Woa! Say what? I think you are totally incorrect here Mike.
Spindle sync is not an anachronism. You c
> Joerg Wunsch wrote:
> > > I guarantee you that there are a number of controllers which have
> > > different ideas of how to do soft sector sparing _at the controller
> > > level_ rather than at the drive level.
> >
> > We have dropped support for ESDI controllers long since. :-)
> >
> > Seriou
Joerg Wunsch wrote:
> > I guarantee you that there are a number of controllers which have
> > different ideas of how to do soft sector sparing _at the controller
> > level_ rather than at the drive level.
>
> We have dropped support for ESDI controllers long since. :-)
>
> Seriously, all the dis
As Terry Lambert wrote:
> Joerg Wunsch wrote:
> > /The/ major advantage of DD mode was that all BIOSes (so far :) at
> > least agree on how to access block 0 and the adjacent blocks, so
> > starting our own system there makes those disks portable.
> I guarantee you that there are a number of con
On Mon, Dec 10, 2001 at 11:04:38AM +0100, Joerg Wunsch wrote:
> As Peter Wemm wrote:
>
> > Can you please clarify for me what specifically you do not like.. Is it:
> > - the cost of 32K of disk space on an average disk these days?
> > (and if so, is reducing that to one sector instead of 62 suf
In message <[EMAIL PROTECTED]>, Peter Wemm writes
:
>The problem is, that you **are** using fdisk tables, you have no choice.
>DD mode included a *broken* fdisk table that specified an illegal geometry.
...
>This is why it is called dangerous.
BTW, I presume you are aware of the way sysinstall cr
As Peter Wemm wrote:
> Can you please clarify for me what specifically you do not like.. Is it:
> - the cost of 32K of disk space on an average disk these days?
> (and if so, is reducing that to one sector instead of 62 sufficient?)
The idea of a "geometry" that does not even remotely resemble
Ah, the thread which would not die... 8^).
Joerg Wunsch wrote:
> /The/ major advantage of DD mode was that all BIOSes (so far :) at
> least agree on how to access block 0 and the adjacent blocks, so
> starting our own system there makes those disks portable.
I guarantee you that there are a numb
As Peter Wemm wrote:
> No, it isn't ignored, BIOS'es "know" that fdisk partitions end on
> cylinder boundaries, and therefore can intuit what the expected
> geometry is for the disk in question.
And you call that a "design"? I call it a poor hack, nothing else.
The restriction to whatever the
Joerg Wunsch wrote:
> Mike Smith <[EMAIL PROTECTED]> wrote:
>
> > - The MBR partition table is not "obsolete", it's a part of the PC
> >architecture specification.
>
> Its design is antique. Or rather: it's missing a design. See other
> mail for the reasons. For FreeBSD, it's obsolete s
On Sun, Dec 09, 2001 at 11:00:19PM +0100, Joerg Wunsch wrote:
> Mike Smith <[EMAIL PROTECTED]> wrote:
> > - The MBR partition table is not "obsolete", it's a part of the PC
> >architecture specification.
>
> Its design is antique. Or rather: it's missing a design. See other
> mail for the
> Joerg Wunsch wrote:
> > Mike Smith <[EMAIL PROTECTED]> wrote:
> > > - The MBR partition table is not "obsolete", it's a part of the PC
> > >architecture specification.
> >
> > Its design is antique. Or rather: it's missing a design. See other
> > mail for the reasons. For FreeBSD, it's o
Joerg Wunsch wrote:
> Mike Smith <[EMAIL PROTECTED]> wrote:
>
> > - The MBR partition table is not "obsolete", it's a part of the PC
> >architecture specification.
>
> Its design is antique. Or rather: it's missing a design. See other
> mail for the reasons. For FreeBSD, it's obsolete s
:This illegal geometry causes divide by zero errors in a handful of scsi
:bioses from Adaptec.
:
:This illegal geometry causes divide by zero errors in a handful of scsi
:bioses from NCR/Symbios.
:
:This is why it is called dangerous.
:
:Cheers,
:-Peter
:--
:Peter Wemm - [EMAIL PROTECTED]; [EMAIL
Joerg Wunsch wrote:
> As Peter Wemm wrote:
>
> > There shouldn't *be* bootblocks on non-boot disks.
> >
> > dd if=/dev/zero of=/dev/da$n count=1
> >
> > Dont use "disklabel -B -rw da$n auto". Use "disklabel -rw da$n auto".
>
> All my disks have bootblocks and (spare) boot partitions. All the
Mike Smith <[EMAIL PROTECTED]> wrote:
> - The MBR partition table is not "obsolete", it's a part of the PC
>architecture specification.
Its design is antique. Or rather: it's missing a design. See other
mail for the reasons. For FreeBSD, it's obsolete since we don't need
to rely on fdis
> (The other day a coworker of mine wanted to use DD for some IBM DTLA
> disks, because he'd heard that the disks performed better that way -
> something to do with scatter-gather not working right unless you used
> DD. I'm highly skeptical about this since I have my own measurements
> from IBM DT
> As Peter Wemm wrote:
>
> > There shouldn't *be* bootblocks on non-boot disks.
> >
> > dd if=/dev/zero of=/dev/da$n count=1
> >
> > Dont use "disklabel -B -rw da$n auto". Use "disklabel -rw da$n auto".
>
> All my disks have bootblocks and (spare) boot partitions. All the
> bootblocks are DD
As [EMAIL PROTECTED] wrote:
> There are very good reasons NOT to use DD mode if you use certain
> types of Adaptec SCSI controllers - they simply won't boot from DD.
Never seen. All my SCSI controllers so far booted from my disks
(obviously :).
I figure from Peter's comment in that piece of co
As Daniel O'Connor wrote:
> I don't understand the need some people have for using something
> that is labelled as DANGEROUS.
Historically, it hasn't been labelled that, it only later became
common terminology for it -- in the typical half-joking manner.
> No, it won't hurt your cats but you ma
On 09-Dec-2001 [EMAIL PROTECTED] wrote:
> (The other day a coworker of mine wanted to use DD for some IBM DTLA
> disks, because he'd heard that the disks performed better that way -
> something to do with scatter-gather not working right unless you used
> DD. I'm highly skeptical about this s
> All my disks have bootblocks and (spare) boot partitions. All the
> bootblocks are DD mode. I don't see any point in using obsolete fdisk
> tables. (There's IMHO only one purpose obsolete fdisk tables are good
> for, co-operation with other operating systems in the same machine.
> None of my
As Peter Wemm wrote:
> There shouldn't *be* bootblocks on non-boot disks.
>
> dd if=/dev/zero of=/dev/da$n count=1
>
> Dont use "disklabel -B -rw da$n auto". Use "disklabel -rw da$n auto".
All my disks have bootblocks and (spare) boot partitions. All the
bootblocks are DD mode. I don't see
On Sat, Dec 08, 2001 at 05:09:11PM -0800, Peter Wemm wrote:
> Joerg Wunsch wrote:
> > Bernd Walter <[EMAIL PROTECTED]> wrote:
> >
> > > 32 times for each disk on booting with most of 30 disks.
> > > Possibly it's triggered by vinums drive scanning.
> >
> > Yep, same here (and it is triggered by
Joerg Wunsch wrote:
> Bernd Walter <[EMAIL PROTECTED]> wrote:
>
> > 32 times for each disk on booting with most of 30 disks.
> > Possibly it's triggered by vinums drive scanning.
>
> Yep, same here (and it is triggered by vinum).
>
> > What can I do about these messages?
>
> Remove it. It sho
:boot block itself). The comments tell a bit more about it. But
:adding pointless messages that flush the boot log and possibly hide
:important boot messages can't be goo.
:
:--
:cheers, J"org .-.-. --... ...-- -.. . DL8DTL
Yes, Goo in the computer is wery, wery bad!
Bernd Walter <[EMAIL PROTECTED]> wrote:
> 32 times for each disk on booting with most of 30 disks.
> Possibly it's triggered by vinums drive scanning.
Yep, same here (and it is triggered by vinum).
> What can I do about these messages?
Remove it. It should not have been there in the first pla
On Wed, Nov 21, 2001 at 12:31:45AM -0800, Peter Wemm wrote:
> peter 2001/11/21 00:31:45 PST
>
> Modified files:
> sys/kern subr_diskmbr.c
> Log:
> Recognize the "fixed" geometry in boot1 so that DD disks are not
> interpreted as real fdisk tables (and fail).
>
>
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