Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Jim Roland said: >I expect someone will rebut my comments about the kernel (which is fine, I'm >not a Kernel hacker Okay, I'll take the bait, but I'm not a kernel hacker, either, so someone should feel free to rebut *my* comments as well. >but it is my understanding that the kernel uses your system BIOS for actual >reads/writes at the hardware level, No. There are many reasons this isn't done, but a big one is: BIOS = real mode Kernel = protected mode The kernel makes use of some BIOS *tables* (which are coped to known locations before the Big Switch), but actual BIOS interrupt routines are used only during the early stages of boot. Aside from the RM/PM issue, the BIOS isn't used because it is 16-bit, slow, and generally buggy. See Alan Cox's paper on kernel BIOS usage posted back on 6/22/01 for a nice discussion of what use the kernel has for the BIOS. >When you turn BIOS to the OS does what it can, but >the BIOS in your system *SHOULD* refuse to process the call, instead it's >doing the read/writes, but not the same way as if IDE was turned on. An interesting theory, but off the mark. That said, I don't know what the Right Answer for Martin is, but here are a few ideas: * I notice the boot log shows a CMD646 IDE controller. Make sure the CMD640 bug-fix support is enabled in your kernel (assuming this applies to 64x chips). If you're using a vendor's kernel it almost certainly is already, but if you built your own, make sure. * It is possible that when a drive is assigned in the BIOS, the BIOS will do some configuration of the controller or the drive itself which the kernel is not doing on its own. I don't know what the state of kernel support for that 646 chipset is. * That's a pretty old drive, so I wouldn't rule out hardware problems. Strange that it only fails when not configured in the BIOS, though. Regards, Adam - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Jim Roland said: I expect someone will rebut my comments about the kernel (which is fine, I'm not a Kernel hacker Okay, I'll take the bait, but I'm not a kernel hacker, either, so someone should feel free to rebut *my* comments as well. but it is my understanding that the kernel uses your system BIOS for actual reads/writes at the hardware level, No. There are many reasons this isn't done, but a big one is: BIOS = real mode Kernel = protected mode The kernel makes use of some BIOS *tables* (which are coped to known locations before the Big Switch), but actual BIOS interrupt routines are used only during the early stages of boot. Aside from the RM/PM issue, the BIOS isn't used because it is 16-bit, slow, and generally buggy. See Alan Cox's paper on kernel BIOS usage posted back on 6/22/01 for a nice discussion of what use the kernel has for the BIOS. When you turn BIOS to NONE the OS does what it can, but the BIOS in your system *SHOULD* refuse to process the call, instead it's doing the read/writes, but not the same way as if IDE was turned on. An interesting theory, but off the mark. That said, I don't know what the Right Answer for Martin is, but here are a few ideas: * I notice the boot log shows a CMD646 IDE controller. Make sure the CMD640 bug-fix support is enabled in your kernel (assuming this applies to 64x chips). If you're using a vendor's kernel it almost certainly is already, but if you built your own, make sure. * It is possible that when a drive is assigned in the BIOS, the BIOS will do some configuration of the controller or the drive itself which the kernel is not doing on its own. I don't know what the state of kernel support for that 646 chipset is. * That's a pretty old drive, so I wouldn't rule out hardware problems. Strange that it only fails when not configured in the BIOS, though. Regards, Adam - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
On Sat, 7 Jul 2001, Jim Roland wrote: > but it's possible that the kernel is making a BIOS call, Not really ... Rik -- Executive summary of a recent Microsoft press release: "we are concerned about the GNU General Public License (GPL)" http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
- Original Message - From: "M.H.VanLeeuwen" <[EMAIL PROTECTED]> To: "Jim Roland" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Saturday, July 07, 2001 8:47 AM Subject: Re: Does kernel require IDE enabled in BIOS to access HD, FS errors? > Jim, > > Thanks for the info, comments interleaved below > [snip] > > But, that's kind of the point I'm driving at if the OS can't correctly access the > IDE interface it shouldn't do it at all. Right. It's possible that your BIOS may be letting the kernel write. While I don't write the kernel, it's probably best for Linus to answer this one, but it's possible that the kernel is making a BIOS call, and the BIOS does not refuse to write data (which it should just say "no IDE drives are on the system right now") with the IDE setting to in your BIOS. OTOH, the kernel may be making calls of it's own or as you say, there may be a broken driver. I seem to remember there was a "bug workaround" option in the kernel for the CMD640 chipset. > > Are you getting IDE corruption with the BIOS set to for your IDE > > drive? > > None whatsoever. Then AFAIK, it's definitely a BIOS issue. There might be (if not there already) a kernel option to check to see what the BIOS setting is for number of IDE drives (of course set to would mean 0 drives), and refuse to write it. This workaround (if any) would be required for buggy BIOSes (I'm sure yours isn't the only one ). - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Jim, Thanks for the info, comments interleaved below Thanks Martin Jim Roland wrote: > > Activating an IDE drive in an older BIOS (newer ones have a SCSI option in > the "A/C/CDROM" options) will always force an IDE drive boot with older > BIOSes. Older BIOSes are written to stop looking for a boot device once it > has found one, and it's own IDE is where it says "Ok, I have boot > capability", otherwise no IDE drive, means it passes boot control to other > system BIOSes (like your SCSI or NIC cards). This is by default with older > systems. This behavior is acceptable, as I can as you suggest move the kernel to the IDE and tell it the root device is /dev/md0. Actually that is what I did to a floppy to get access to the system while the BIOS was set to detect the IDE drives. Since I only boot whenever Linus puts out a new kernel that isn't so much of a concern. > > I expect someone will rebut my comments about the kernel (which is fine, I'm > not a Kernel hacker--PROPERLY USED TERM HERE (not the media's term) ), > but it is my understanding that the kernel uses your system BIOS for actual > reads/writes at the hardware level, this way it does not have to account for > EVERY possible BIOS out there. (Other OSes use BIOS system calls for this > purpose as well) When you turn BIOS to the OS does what it can, but > the BIOS in your system *SHOULD* refuse to process the call, instead it's > doing the read/writes, but not the same way as if IDE was turned on. But, that's kind of the point I'm driving at if the OS can't correctly access the IDE interface it shouldn't do it at all. My guess is that the CMD64X driver is broken since the system can write data to the HD but with random corruption. Ditto for reading data. Likewise, why would I see an increase in write performance when "dd if=/dev/zero of=/dev/null" is running simultaneously on another console. > Are you getting IDE corruption with the BIOS set to for your IDE > drive? None whatsoever. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Activating an IDE drive in an older BIOS (newer ones have a SCSI option in
the "A/C/CDROM" options) will always force an IDE drive boot with older
BIOSes. Older BIOSes are written to stop looking for a boot device once it
has found one, and it's own IDE is where it says "Ok, I have boot
capability", otherwise no IDE drive, means it passes boot control to other
system BIOSes (like your SCSI or NIC cards). This is by default with older
systems.
I expect someone will rebut my comments about the kernel (which is fine, I'm
not a Kernel hacker--PROPERLY USED TERM HERE (not the media's term) ),
but it is my understanding that the kernel uses your system BIOS for actual
reads/writes at the hardware level, this way it does not have to account for
EVERY possible BIOS out there. (Other OSes use BIOS system calls for this
purpose as well) When you turn BIOS to the OS does what it can, but
the BIOS in your system *SHOULD* refuse to process the call, instead it's
doing the read/writes, but not the same way as if IDE was turned on.
My suggestion is that you install the OS onto the IDE drive, let it boot,
and use it for a boot only drive. Mount user data from your SCSI drive onto
the IDE's mount points. Otherwise, since your reason for doing this is that
you're out of space, add another SCSI drive.
Are you getting IDE corruption with the BIOS set to for your IDE
drive?
Regards,
Jim Roland, RHCE
- Original Message -
From: "M.H.VanLeeuwen" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, July 07, 2001 12:25 AM
Subject: Does kernel require IDE enabled in BIOS to access HD, FS errors?
> Hi,
>
> I have a SMP P166 system that has been running for years with an AIC7xxx
SCSI card as
> opposed to the native IDE interface. The BIOS has the IDE 0,1,2,3 set to
.
> Running out of disk space I installed one of the original IDE drives. The
kernel
> booted and ID'd the drive correctly. Kernel version 2.4.5/6 behave the
same.
>
> Uniform Multi-Platform E-IDE driver Revision: 6.31
> ide: Assuming 33MHz system bus speed for PIO modes; override with
idebus=xx
> CMD646: IDE controller on PCI bus 00 dev 10
> CMD646: chipset revision 1
> CMD646: not 100% native mode: will probe irqs later
> CMD646: chipset revision 0x01, MultiWord DMA Limited, IRQ workaround
enabled
> CMD646: simplex device: DMA disabled
> ide0: CMD646 Bus-Master DMA disabled (BIOS)
> CMD646: simplex device: DMA disabled
> ide1: CMD646 Bus-Master DMA disabled (BIOS)
> hdb: CD-ROM CDU76E, ATAPI CD/DVD-ROM drive
> ide: Assuming 33MHz system bus speed for PIO modes; override with
idebus=xx
> hdc: WDC AC2850F, ATA DISK drive
> ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
> ide1 at 0x170-0x177,0x376 on irq 15
> hdc: 1667232 sectors (854 MB) w/64KiB Cache, CHS=1654/16/63
> hdb: packet command error: status=0x51 { DriveReady SeekComplete Error }
> hdb: packet command error: error=0x44
> hdb: ATAPI 4X CD-ROM drive, 256kB Cache
> Uniform CD-ROM driver Revision: 3.12
> Partition check:
> hdc: [PTBL] [827/32/63] hdc1
>
> However I can't boot from the SCSI drives if the IDE HD is enabled due to
deficiencies
> in the BIOS... boot "A: then C:" or "C: then A:" are the only choices, if
neither are
> present the system boots from the SCSI card, otherwise it fails to boot.
>
> PROBLEM: cannot reliably R/W to the HD unless the BIOS is set to
recognize.
> I consistently see MD5SUM errors and FS corruption and other strange FS
symptoms
> when the BIOS is set to for the drive and _never_ see any errors
with the
> setting set to . There are no messages emitted by the kernel that
there
> were any system errors encountered leading one to believe that all is
well, when
> it isn't.
>
> What is interesting, is that the I/O writes increase from once every 14
seconds to
> once every 2-3 seconds and the FS corruption diminishes but don't
disappear
> if a background "dd if=/dev/zero of=/dev/null" is running.
>
> Is this expected kernel behavior?
>
> VMSTAT follow... when copying files from SCSI drives to IDE drive.
>
> More info available if needed...
>
> Thanks,
> Martin
>
> The waiting processes are kupdated and bdflush. (I have Alt-SysRq- trace
of them)
>
> VMSTAT 1 for the case w/ BIOS set to looks like (w/o dd running):
>
>procs memoryswap io system
cpu
> r b w swpd free buff cache si sobibo incs us
sy id
> 0 0 0 0 83180 1056 39800 0 0 261 3 8343 5
8 87
> 0 0 0 0 83176 1056 39800 0 0 0 0 11920 3
2 95
> 0 0 0 0 83176 1056 39800 0 0 0 0 11620 2
2 96
> 0 1 0 0 83012 1096 39812 0 0 329 0 196 183 3
8 89
> 0 1 0 0 81268 1128 41444 0 0 1021 0 309 275 3
17 80
> 0 1 0 0 74464 1200 47716 0 0 313127 292 264 6
25 69
> 2 0 0 0 67772 1276 53632 0 0 2962 0 397 245 12
25 63
> 2 0 0 0 64016 1324 56900 0
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Activating an IDE drive in an older BIOS (newer ones have a SCSI option in
the A/C/CDROM options) will always force an IDE drive boot with older
BIOSes. Older BIOSes are written to stop looking for a boot device once it
has found one, and it's own IDE is where it says Ok, I have boot
capability, otherwise no IDE drive, means it passes boot control to other
system BIOSes (like your SCSI or NIC cards). This is by default with older
systems.
I expect someone will rebut my comments about the kernel (which is fine, I'm
not a Kernel hacker--PROPERLY USED TERM HERE (not the media's term) grin),
but it is my understanding that the kernel uses your system BIOS for actual
reads/writes at the hardware level, this way it does not have to account for
EVERY possible BIOS out there. (Other OSes use BIOS system calls for this
purpose as well) When you turn BIOS to NONE the OS does what it can, but
the BIOS in your system *SHOULD* refuse to process the call, instead it's
doing the read/writes, but not the same way as if IDE was turned on.
My suggestion is that you install the OS onto the IDE drive, let it boot,
and use it for a boot only drive. Mount user data from your SCSI drive onto
the IDE's mount points. Otherwise, since your reason for doing this is that
you're out of space, add another SCSI drive.
Are you getting IDE corruption with the BIOS set to AUTO for your IDE
drive?
Regards,
Jim Roland, RHCE
- Original Message -
From: M.H.VanLeeuwen [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Saturday, July 07, 2001 12:25 AM
Subject: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Hi,
I have a SMP P166 system that has been running for years with an AIC7xxx
SCSI card as
opposed to the native IDE interface. The BIOS has the IDE 0,1,2,3 set to
NONE.
Running out of disk space I installed one of the original IDE drives. The
kernel
booted and ID'd the drive correctly. Kernel version 2.4.5/6 behave the
same.
Uniform Multi-Platform E-IDE driver Revision: 6.31
ide: Assuming 33MHz system bus speed for PIO modes; override with
idebus=xx
CMD646: IDE controller on PCI bus 00 dev 10
CMD646: chipset revision 1
CMD646: not 100% native mode: will probe irqs later
CMD646: chipset revision 0x01, MultiWord DMA Limited, IRQ workaround
enabled
CMD646: simplex device: DMA disabled
ide0: CMD646 Bus-Master DMA disabled (BIOS)
CMD646: simplex device: DMA disabled
ide1: CMD646 Bus-Master DMA disabled (BIOS)
hdb: CD-ROM CDU76E, ATAPI CD/DVD-ROM drive
ide: Assuming 33MHz system bus speed for PIO modes; override with
idebus=xx
hdc: WDC AC2850F, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hdc: 1667232 sectors (854 MB) w/64KiB Cache, CHS=1654/16/63
hdb: packet command error: status=0x51 { DriveReady SeekComplete Error }
hdb: packet command error: error=0x44
hdb: ATAPI 4X CD-ROM drive, 256kB Cache
Uniform CD-ROM driver Revision: 3.12
Partition check:
hdc: [PTBL] [827/32/63] hdc1
However I can't boot from the SCSI drives if the IDE HD is enabled due to
deficiencies
in the BIOS... boot A: then C: or C: then A: are the only choices, if
neither are
present the system boots from the SCSI card, otherwise it fails to boot.
PROBLEM: cannot reliably R/W to the HD unless the BIOS is set to auto
recognize.
I consistently see MD5SUM errors and FS corruption and other strange FS
symptoms
when the BIOS is set to NONE for the drive and _never_ see any errors
with the
setting set to AUTO. There are no messages emitted by the kernel that
there
were any system errors encountered leading one to believe that all is
well, when
it isn't.
What is interesting, is that the I/O writes increase from once every 14
seconds to
once every 2-3 seconds and the FS corruption diminishes but don't
disappear
if a background dd if=/dev/zero of=/dev/null is running.
Is this expected kernel behavior?
VMSTAT follow... when copying files from SCSI drives to IDE drive.
More info available if needed...
Thanks,
Martin
The waiting processes are kupdated and bdflush. (I have Alt-SysRq- trace
of them)
VMSTAT 1 for the case w/ BIOS set to NONE looks like (w/o dd running):
procs memoryswap io system
cpu
r b w swpd free buff cache si sobibo incs us
sy id
0 0 0 0 83180 1056 39800 0 0 261 3 8343 5
8 87
0 0 0 0 83176 1056 39800 0 0 0 0 11920 3
2 95
0 0 0 0 83176 1056 39800 0 0 0 0 11620 2
2 96
0 1 0 0 83012 1096 39812 0 0 329 0 196 183 3
8 89
0 1 0 0 81268 1128 41444 0 0 1021 0 309 275 3
17 80
0 1 0 0 74464 1200 47716 0 0 313127 292 264 6
25 69
2 0 0 0 67772 1276 53632 0 0 2962 0 397 245 12
25 63
2 0 0 0 64016 1324 56900 0 0 1602 0 414 155 48
27 26
1 1 0
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
Jim, Thanks for the info, comments interleaved below Thanks Martin Jim Roland wrote: Activating an IDE drive in an older BIOS (newer ones have a SCSI option in the A/C/CDROM options) will always force an IDE drive boot with older BIOSes. Older BIOSes are written to stop looking for a boot device once it has found one, and it's own IDE is where it says Ok, I have boot capability, otherwise no IDE drive, means it passes boot control to other system BIOSes (like your SCSI or NIC cards). This is by default with older systems. This behavior is acceptable, as I can as you suggest move the kernel to the IDE and tell it the root device is /dev/md0. Actually that is what I did to a floppy to get access to the system while the BIOS was set to auto detect the IDE drives. Since I only boot whenever Linus puts out a new kernel that isn't so much of a concern. I expect someone will rebut my comments about the kernel (which is fine, I'm not a Kernel hacker--PROPERLY USED TERM HERE (not the media's term) grin), but it is my understanding that the kernel uses your system BIOS for actual reads/writes at the hardware level, this way it does not have to account for EVERY possible BIOS out there. (Other OSes use BIOS system calls for this purpose as well) When you turn BIOS to NONE the OS does what it can, but the BIOS in your system *SHOULD* refuse to process the call, instead it's doing the read/writes, but not the same way as if IDE was turned on. But, that's kind of the point I'm driving at if the OS can't correctly access the IDE interface it shouldn't do it at all. My guess is that the CMD64X driver is broken since the system can write data to the HD but with random corruption. Ditto for reading data. Likewise, why would I see an increase in write performance when dd if=/dev/zero of=/dev/null is running simultaneously on another console. Are you getting IDE corruption with the BIOS set to AUTO for your IDE drive? None whatsoever. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
- Original Message - From: M.H.VanLeeuwen [EMAIL PROTECTED] To: Jim Roland [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Saturday, July 07, 2001 8:47 AM Subject: Re: Does kernel require IDE enabled in BIOS to access HD, FS errors? Jim, Thanks for the info, comments interleaved below [snip] But, that's kind of the point I'm driving at if the OS can't correctly access the IDE interface it shouldn't do it at all. Right. It's possible that your BIOS may be letting the kernel write. While I don't write the kernel, it's probably best for Linus to answer this one, but it's possible that the kernel is making a BIOS call, and the BIOS does not refuse to write data (which it should just say no IDE drives are on the system right now) with the IDE setting to NONE in your BIOS. OTOH, the kernel may be making calls of it's own or as you say, there may be a broken driver. I seem to remember there was a bug workaround option in the kernel for the CMD640 chipset. Are you getting IDE corruption with the BIOS set to AUTO for your IDE drive? None whatsoever. Then AFAIK, it's definitely a BIOS issue. There might be (if not there already) a kernel option to check to see what the BIOS setting is for number of IDE drives (of course set to NONE would mean 0 drives), and refuse to write it. This workaround (if any) would be required for buggy BIOSes (I'm sure yours isn't the only one grin). - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Does kernel require IDE enabled in BIOS to access HD, FS errors?
On Sat, 7 Jul 2001, Jim Roland wrote: but it's possible that the kernel is making a BIOS call, Not really ... Rik -- Executive summary of a recent Microsoft press release: we are concerned about the GNU General Public License (GPL) http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com/ - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
