I've a very annoying behavior with the linux-3.6.x kernels release, and
a monolithic configuration. The USB 2.0 drives are mapped first with
/dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come after.
This is out of order with the BIOS configuration and breaks a program
like lilo. This is also annoying when we use a static partition mapping.
Linux-3.5 works fine. Where this bug come from ? Is this a patch to get
the old, and classical behavior ?
Best Regards,
Wallak.
On 10/25/2012 04:49 PM, Wallak wrote:
> I've a very annoying behavior with the linux-3.6.x kernels release, and
> a monolithic configuration. The USB 2.0 drives are mapped first with
> /dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come after.
> This is out of order with the BIOS configuration and breaks a program
> like lilo. This is also annoying when we use a static partition mapping.
>
> Linux-3.5 works fine. Where this bug come from ? Is this a patch to get
> the old, and classical behavior ?
As you have discovered it's fragile to rely on /dev/sd* names since a
BIOS update, kernel update, or motherboard replacement could conceivably
cause them to change.
Better to use something like partition labels that you control and that
don't change.
Chris
Chris Friesen wrote:
> On 10/25/2012 04:49 PM, Wallak wrote:
>> I've a very annoying behavior with the linux-3.6.x kernels release, and
>> a monolithic configuration. The USB 2.0 drives are mapped first with
>> /dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come after.
>> This is out of order with the BIOS configuration and breaks a program
>> like lilo. This is also annoying when we use a static partition mapping.
>>
>> Linux-3.5 works fine. Where this bug come from ? Is this a patch to get
>> the old, and classical behavior ?
>
> As you have discovered it's fragile to rely on /dev/sd* names since a
> BIOS update, kernel update, or motherboard replacement could
> conceivably cause them to change.
>
> Better to use something like partition labels that you control and
> that don't change.
>
> Chris
>
You are right, when we have a configuration with a lot of drvies and
adapters SATA, old SCSI,.. etc. the order may change. But having the
main SATA hard drive defined, as the BIOS boot device, behind external
and removable USB drives is in my opinion a bug.And may lead to security
issues (drives with the same label, etc...).
Using =LABEL, or =UUID with a bootloader like grub or lilo, save the
the boot device mapped drive partition number , and so booting on an
older kernel like linux 3.5 will fail. If we remove the external USB
drive, the boot process will fail too...
So such a bug have to be fix.
Wallak.
On 10/26/2012 01:43 PM, Wallak wrote:
> Chris Friesen wrote:
>> On 10/25/2012 04:49 PM, Wallak wrote:
>>> I've a very annoying behavior with the linux-3.6.x kernels release, and
>>> a monolithic configuration. The USB 2.0 drives are mapped first with
>>> /dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come after.
>>> This is out of order with the BIOS configuration and breaks a program
>>> like lilo. This is also annoying when we use a static partition mapping.
>>>
>>> Linux-3.5 works fine. Where this bug come from ? Is this a patch to get
>>> the old, and classical behavior ?
>>
>> As you have discovered it's fragile to rely on /dev/sd* names since a
>> BIOS update, kernel update, or motherboard replacement could
>> conceivably cause them to change.
>>
>> Better to use something like partition labels that you control and
>> that don't change.
>>
>> Chris
>>
> You are right, when we have a configuration with a lot of drvies and
> adapters SATA, old SCSI,.. etc. the order may change. But having the
> main SATA hard drive defined, as the BIOS boot device, behind external
> and removable USB drives is in my opinion a bug.And may lead to security
> issues (drives with the same label, etc...).
>
> Using =LABEL, or =UUID with a bootloader like grub or lilo, save the the
> boot device mapped drive partition number , and so booting on an older
> kernel like linux 3.5 will fail. If we remove the external USB drive,
> the boot process will fail too...
>
> So such a bug have to be fix.
If you specify "root=LABEL=<label>" as part of the kernel boot args in
grub does it not check the label at boot time?
Chris
Chris Friesen wrote:
> On 10/26/2012 01:43 PM, Wallak wrote:
>> Chris Friesen wrote:
>>> On 10/25/2012 04:49 PM, Wallak wrote:
>>>> I've a very annoying behavior with the linux-3.6.x kernels release,
>>>> and
>>>> a monolithic configuration. The USB 2.0 drives are mapped first with
>>>> /dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come
>>>> after.
>>>> This is out of order with the BIOS configuration and breaks a program
>>>> like lilo. This is also annoying when we use a static partition
>>>> mapping.
>>>>
>>>> Linux-3.5 works fine. Where this bug come from ? Is this a patch to
>>>> get
>>>> the old, and classical behavior ?
>>>
>>> As you have discovered it's fragile to rely on /dev/sd* names since a
>>> BIOS update, kernel update, or motherboard replacement could
>>> conceivably cause them to change.
>>>
>>> Better to use something like partition labels that you control and
>>> that don't change.
>>>
>>> Chris
>>>
>> You are right, when we have a configuration with a lot of drvies and
>> adapters SATA, old SCSI,.. etc. the order may change. But having the
>> main SATA hard drive defined, as the BIOS boot device, behind external
>> and removable USB drives is in my opinion a bug.And may lead to security
>> issues (drives with the same label, etc...).
>>
>> Using =LABEL, or =UUID with a bootloader like grub or lilo, save the the
>> boot device mapped drive partition number , and so booting on an older
>> kernel like linux 3.5 will fail. If we remove the external USB drive,
>> the boot process will fail too...
>>
>> So such a bug have to be fix.
>
> If you specify "root=LABEL=<label>" as part of the kernel boot args in
> grub does it not check the label at boot time?
Using root=LABEL= or root=UUID= don't work on a plain kernel, this
feature may be handled by an initrd trick. Otherwise for all non root
partitions UUID= work fine.
Nevertheless not fixing this bug yields some other issues: Using lilo
to launch a second OS (other= option) fail, the command try to parse
partitions available on /dev/sda, and miss the real main HDD. Boot drive
must be force with lilo options...
SATA drives have, most of the time, no reason to be behind USB drives.
If we want to get a reliable behavior: /dev/sda must be mapped to the
BIOS boot device. Using the same behavior as linux-3.5 will be fine.
Wallak.
>
> Chris
>
I've found where this issue come from. This behavior was introduced with
the commit: 0cc15d03bcccdf95e2bd82e094e6064e61b54207.The description is
available below. Removing this patch fix the drive order.
Best Regards,
Wallak.
commit 0cc15d03bcccdf95e2bd82e094e6064e61b54207
Author: Andi Kleen <[email protected]>
Date: Mon Jul 2 17:27:04 2012 -0700
floppy: Run floppy initialization asynchronous
floppy_init is quite slow, 3s on my test system to determine
that there is no floppy. Run it asynchronous to the other
init calls to improve boot time.
[[email protected]: fix modular build]
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>
Wallak wrote:
> Chris Friesen wrote:
>> On 10/26/2012 01:43 PM, Wallak wrote:
>>> Chris Friesen wrote:
>>>> On 10/25/2012 04:49 PM, Wallak wrote:
>>>>> I've a very annoying behavior with the linux-3.6.x kernels
>>>>> release, and
>>>>> a monolithic configuration. The USB 2.0 drives are mapped first with
>>>>> /dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come
>>>>> after.
>>>>> This is out of order with the BIOS configuration and breaks a program
>>>>> like lilo. This is also annoying when we use a static partition
>>>>> mapping.
>>>>>
>>>>> Linux-3.5 works fine. Where this bug come from ? Is this a patch
>>>>> to get
>>>>> the old, and classical behavior ?
>>>>
>>>> As you have discovered it's fragile to rely on /dev/sd* names since a
>>>> BIOS update, kernel update, or motherboard replacement could
>>>> conceivably cause them to change.
>>>>
>>>> Better to use something like partition labels that you control and
>>>> that don't change.
>>>>
>>>> Chris
>>>>
>>> You are right, when we have a configuration with a lot of drvies and
>>> adapters SATA, old SCSI,.. etc. the order may change. But having the
>>> main SATA hard drive defined, as the BIOS boot device, behind external
>>> and removable USB drives is in my opinion a bug.And may lead to
>>> security
>>> issues (drives with the same label, etc...).
>>>
>>> Using =LABEL, or =UUID with a bootloader like grub or lilo, save the
>>> the
>>> boot device mapped drive partition number , and so booting on an older
>>> kernel like linux 3.5 will fail. If we remove the external USB drive,
>>> the boot process will fail too...
>>>
>>> So such a bug have to be fix.
>>
>> If you specify "root=LABEL=<label>" as part of the kernel boot args
>> in grub does it not check the label at boot time?
>
> Using root=LABEL= or root=UUID= don't work on a plain kernel, this
> feature may be handled by an initrd trick. Otherwise for all non root
> partitions UUID= work fine.
> Nevertheless not fixing this bug yields some other issues: Using lilo
> to launch a second OS (other= option) fail, the command try to parse
> partitions available on /dev/sda, and miss the real main HDD. Boot
> drive must be force with lilo options...
> SATA drives have, most of the time, no reason to be behind USB drives.
> If we want to get a reliable behavior: /dev/sda must be mapped to the
> BIOS boot device. Using the same behavior as linux-3.5 will be fine.
>
> Wallak.
>
>>
>> Chris
>>
>
On Sun, Oct 28, 2012 at 04:17:00AM +0100, Wallak wrote:
> I've found where this issue come from. This behavior was introduced
> with the commit: 0cc15d03bcccdf95e2bd82e094e6064e61b54207.The
> description is available below. Removing this patch fix the drive
> order.
Hmm the patch should only affect the floppy. I don't see how it could
affect anything else. Maybe it's just generic timing change
that disrupts your boot sequence (if that's the case something else
could have caused it too)
Maybe Arjan has an idea.
-Andi
>
>
> Best Regards,
> Wallak.
>
>
> commit 0cc15d03bcccdf95e2bd82e094e6064e61b54207
> Author: Andi Kleen <[email protected]>
> Date: Mon Jul 2 17:27:04 2012 -0700
>
> floppy: Run floppy initialization asynchronous
>
> floppy_init is quite slow, 3s on my test system to determine
> that there is no floppy. Run it asynchronous to the other
> init calls to improve boot time.
>
> [[email protected]: fix modular build]
>
> Signed-off-by: Andi Kleen <[email protected]>
> Signed-off-by: Jiri Kosina <[email protected]>
>
>
>
>
> Wallak wrote:
> >Chris Friesen wrote:
> >>On 10/26/2012 01:43 PM, Wallak wrote:
> >>>Chris Friesen wrote:
> >>>>On 10/25/2012 04:49 PM, Wallak wrote:
> >>>>>I've a very annoying behavior with the linux-3.6.x kernels
> >>>>>release, and
> >>>>>a monolithic configuration. The USB 2.0 drives are mapped first with
> >>>>>/dev/sda, /dev/sdb... devices, and than the SATA AHCI
> >>>>>drives come after.
> >>>>>This is out of order with the BIOS configuration and breaks a program
> >>>>>like lilo. This is also annoying when we use a static
> >>>>>partition mapping.
> >>>>>
> >>>>>Linux-3.5 works fine. Where this bug come from ? Is this a
> >>>>>patch to get
> >>>>>the old, and classical behavior ?
> >>>>
> >>>>As you have discovered it's fragile to rely on /dev/sd* names since a
> >>>>BIOS update, kernel update, or motherboard replacement could
> >>>>conceivably cause them to change.
> >>>>
> >>>>Better to use something like partition labels that you control and
> >>>>that don't change.
> >>>>
> >>>>Chris
> >>>>
> >>>You are right, when we have a configuration with a lot of drvies and
> >>>adapters SATA, old SCSI,.. etc. the order may change. But having the
> >>>main SATA hard drive defined, as the BIOS boot device, behind external
> >>>and removable USB drives is in my opinion a bug.And may lead
> >>>to security
> >>>issues (drives with the same label, etc...).
> >>>
> >>>Using =LABEL, or =UUID with a bootloader like grub or lilo,
> >>>save the the
> >>>boot device mapped drive partition number , and so booting on an older
> >>>kernel like linux 3.5 will fail. If we remove the external USB drive,
> >>>the boot process will fail too...
> >>>
> >>>So such a bug have to be fix.
> >>
> >>If you specify "root=LABEL=<label>" as part of the kernel boot
> >>args in grub does it not check the label at boot time?
> >
> >Using root=LABEL= or root=UUID= don't work on a plain kernel, this
> >feature may be handled by an initrd trick. Otherwise for all non
> >root partitions UUID= work fine.
> >Nevertheless not fixing this bug yields some other issues: Using
> >lilo to launch a second OS (other= option) fail, the command try
> >to parse partitions available on /dev/sda, and miss the real main
> >HDD. Boot drive must be force with lilo options...
> >SATA drives have, most of the time, no reason to be behind USB
> >drives. If we want to get a reliable behavior: /dev/sda must be
> >mapped to the BIOS boot device. Using the same behavior as
> >linux-3.5 will be fine.
> >
> >Wallak.
> >
> >>
> >>Chris
> >>
> >
>
--
[email protected] -- Speaking for myself only