On Thu, Dec 20, 2007 at 08:46:41AM -0800, Pradipmaya Maharana wrote:
> Hi,
>
> Pardon my knowledge on Linux, but in your article did you mean that
> the /boot should be on a local disk and /root, swap can be on
> multipath device.
>
> I am trying to install /boot, /root and swap all on one multipath
> device and try to boot from it. It does not boot, no error just blank
> screen. My equirement is to install everything on multipath device; so
> is it possible at all? I mean can I have the boot device (/boot) too
> on a multipath device.
>
> Following is what I tried on RHEL
> - selected "linux mpath"
> - I could see one local disk and 3 multipath devices
> - I chose custom partition type
> - instead of going for LVM, I selected one single multipath device
> and installed everything on it (/boot, / and swap).
> - Tried rebooting, it won't boot
>
> What am I missing here?

I haven't ever tried putting swap on a multipath device, but I believe
it should work. Your steps seem correct. Are you getting any messages
at all on the console when you boot up?

One thing you need to be aware of is that while multipathed root is
pretty simple, for multipathed boot to work, your machine needs to be
able to boot from the device that your are multipathing with no help
from any linux device drivers (since they obviously can't be loaded
until you run the boot loader). I believe some machines need something
to be set in BIOS in order to try and boot off SAN storage.

To narrow down the problem, I would try setting up the same
configuration, but without multipathing the device. If this doesn't
work, then you are probably having problems booting from your storage.
If it does work, then when you set it up with multipathing, you should
at least be making it past GRUB, and looking at the console output
should shed some light on what's going wrong.

Note, if you have a device that needs a prio_callout, multipath will
still fail in the all paths down case, because it can't access the
callout program. The upstream code currently fixes that by using
callout library functions, and the next device-mapper-multipath package
from RHEL will fix it by caching the callouts in a private namespace.

-Ben

> Thanks and Regards,
> Pradipmaya.
>
>
> On 12/19/07, Pradipmaya Maharana <pradipmaya@gmail.com> wrote:
> > Hi Chandra,
> >
> > Thanks. I will givei it a try.
> >
> > Regards,
> > Pradipmaya.
> >
> > On 12/19/07, Chandra Seetharaman <sekharan@us.ibm.com> wrote:
> > > I am working on a multipath usage document. Attached is the installation
> > > section of that document.
> > >
> > > Note that it is written for RHEL5 U1 and SLES10 SP1.
> > >
> > > Good Luck,
> > >
> > > chandra
> > >
> > > On Wed, 2007-12-19 at 13:02 -0800, Pradipmaya Maharana wrote:
> > > > Hi All,
> > > >
> > > > Is there a process/document that talks about how to configure
> > > > root/boot device for multipath?
> > > >
> > > > Thanks and Regards,
> > > > Pradipmaya.
> > > >
> > > > --
> > > > dm-devel mailing list
> > > > dm-devel@redhat.com
> > > > https://www.redhat.com/mailman/listinfo/dm-devel
> > > --
> > >
> > > ----------------------------------------------------------------------
> > > Chandra Seetharaman | Be careful what you choose....
> > > - sekharan@us.ibm.com | .......you may get it.
> > > ----------------------------------------------------------------------
> > >
> > >
> > > --
> > > dm-devel mailing list
> > > dm-devel@redhat.com
> > > https://www.redhat.com/mailman/listinfo/dm-devel
> > >
> > >
> >
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Hey Ben,

Thanks for your inputs. I will give it another try and let you know if
it worked.

Regards,
Pradipmaya.

On 12/21/07, Benjamin Marzinski <bmarzins@redhat.com> wrote:
> On Thu, Dec 20, 2007 at 08:46:41AM -0800, Pradipmaya Maharana wrote:
> > Hi,
> >
> > Pardon my knowledge on Linux, but in your article did you mean that
> > the /boot should be on a local disk and /root, swap can be on
> > multipath device.
> >
> > I am trying to install /boot, /root and swap all on one multipath
> > device and try to boot from it. It does not boot, no error just blank
> > screen. My equirement is to install everything on multipath device; so
> > is it possible at all? I mean can I have the boot device (/boot) too
> > on a multipath device.
> >
> > Following is what I tried on RHEL
> > - selected "linux mpath"
> > - I could see one local disk and 3 multipath devices
> > - I chose custom partition type
> > - instead of going for LVM, I selected one single multipath device
> > and installed everything on it (/boot, / and swap).
> > - Tried rebooting, it won't boot
> >
> > What am I missing here?
>
> I haven't ever tried putting swap on a multipath device, but I believe
> it should work. Your steps seem correct. Are you getting any messages
> at all on the console when you boot up?
>
> One thing you need to be aware of is that while multipathed root is
> pretty simple, for multipathed boot to work, your machine needs to be
> able to boot from the device that your are multipathing with no help
> from any linux device drivers (since they obviously can't be loaded
> until you run the boot loader). I believe some machines need something
> to be set in BIOS in order to try and boot off SAN storage.
>
> To narrow down the problem, I would try setting up the same
> configuration, but without multipathing the device. If this doesn't
> work, then you are probably having problems booting from your storage.
> If it does work, then when you set it up with multipathing, you should
> at least be making it past GRUB, and looking at the console output
> should shed some light on what's going wrong.
>
> Note, if you have a device that needs a prio_callout, multipath will
> still fail in the all paths down case, because it can't access the
> callout program. The upstream code currently fixes that by using
> callout library functions, and the next device-mapper-multipath package
> from RHEL will fix it by caching the callouts in a private namespace.
>
> -Ben
>
> > Thanks and Regards,
> > Pradipmaya.
> >
> >
> > On 12/19/07, Pradipmaya Maharana <pradipmaya@gmail.com> wrote:
> > > Hi Chandra,
> > >
> > > Thanks. I will givei it a try.
> > >
> > > Regards,
> > > Pradipmaya.
> > >
> > > On 12/19/07, Chandra Seetharaman <sekharan@us.ibm.com> wrote:
> > > > I am working on a multipath usage document. Attached is the installation
> > > > section of that document.
> > > >
> > > > Note that it is written for RHEL5 U1 and SLES10 SP1.
> > > >
> > > > Good Luck,
> > > >
> > > > chandra
> > > >
> > > > On Wed, 2007-12-19 at 13:02 -0800, Pradipmaya Maharana wrote:
> > > > > Hi All,
> > > > >
> > > > > Is there a process/document that talks about how to configure
> > > > > root/boot device for multipath?
> > > > >
> > > > > Thanks and Regards,
> > > > > Pradipmaya.
> > > > >
> > > > > --
> > > > > dm-devel mailing list
> > > > > dm-devel@redhat.com
> > > > > https://www.redhat.com/mailman/listinfo/dm-devel
> > > > --
> > > >
> > > > ----------------------------------------------------------------------
> > > > Chandra Seetharaman | Be careful what you choose....
> > > > - sekharan@us.ibm.com | .......you may get it.
> > > > ----------------------------------------------------------------------
> > > >
> > > >
> > > > --
> > > > dm-devel mailing list
> > > > dm-devel@redhat.com
> > > > https://www.redhat.com/mailman/listinfo/dm-devel
> > > >
> > > >
> > >
> >
> > --
> > dm-devel mailing list
> > dm-devel@redhat.com
> > https://www.redhat.com/mailman/listinfo/dm-devel
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Chandra Seetharaman wrote:
> I am working on a multipath usage document. Attached is the installation
> section of that document.
>
> Note that it is written for RHEL5 U1 and SLES10 SP1.
>
> Good Luck,
>
> chandra
>
> On Wed, 2007-12-19 at 13:02 -0800, Pradipmaya Maharana wrote:
>> Hi All,
>>
>> Is there a process/document that talks about how to configure
>> root/boot device for multipath?
>>
>> Thanks and Regards,
>> Pradipmaya.
>>
>> --
>> dm-devel mailing list
>> dm-devel@redhat.com
>> https://www.redhat.com/mailman/listinfo/dm-devel
>>
>> ------------------------------------------------------------------------
>>
>> 4.1. Installation instructions for SLES10
>>
>> Note: This is tested on SLES10 SP1. If you have any other version, your
>> mileage may vary.
>>
>> 1. Install the OS in a device that has multiple paths. Make sure the
>> root device's "Mount by" option is set to "Device by-id" (this option is
>> available under "expert partitioner" as "fstab options").
>> 2. Complete the installation. Let the system boot up in multiuser mode.
>> Make sure the root device, swap device are all referenced by their by-id
>> device node entries instead of /dev/sd* type names. If they are not, fix
>> them first.
>> 3. Once booted, update /etc/multipath.conf If you have to make changes
>> to /etc/multipath.conf, make the changes.
>> Note: the option "user_friendly_names" is not supported by initrd.
>> So, if you have user_friendly_names in your /etc/multipath.conf file,
>> comment it for now, you can uncomment it later.
>> 4. Enable multipathing by running the following commands
>> * chkconfig boot.multipath on
>>
>> * chkconfig multipathd on
>> 5. Add multipath module to initrd
>>
>> Edit the file /etc/sysconfig/kernel and add "dm-multipath" to
>> INITRD_MODULES". Note: If your storage devices needs a hardware handler,
>> add the corresponding module to INITRD_MODULES, in addition to
>> "dm-multipath". For example add "dm-rdac" and "dm-multipath" to support
>> IBM's DS4K storage devices
>> 6. Run mkinitrd
>> Note: You can uncomment the user friendly name if you have commented it above.
>> 7. Reboot
>>
>> The system will come up with the root disk on a multipathed device.
>>
>> Note: You can switch off multipathing to the root device by adding
>> multipath=off to the kernel command line.
>>
ACK. This is the correct way.

Thanks for writing this up.

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Hi All,

Yes, I tried the steps and it worked for me.
Thanks for your help.

Regards,
Pradipmaya.


On Jan 6, 2008 11:38 PM, Hannes Reinecke <hare@suse.de> wrote:
> Chandra Seetharaman wrote:
> > I am working on a multipath usage document. Attached is the installation
> > section of that document.
> >
> > Note that it is written for RHEL5 U1 and SLES10 SP1.
> >
> > Good Luck,
> >
> > chandra
> >
> > On Wed, 2007-12-19 at 13:02 -0800, Pradipmaya Maharana wrote:
> >> Hi All,
> >>
> >> Is there a process/document that talks about how to configure
> >> root/boot device for multipath?
> >>
> >> Thanks and Regards,
> >> Pradipmaya.
> >>
> >> --
> >> dm-devel mailing list
> >> dm-devel@redhat.com
> >> https://www.redhat.com/mailman/listinfo/dm-devel
> >>
> >> ------------------------------------------------------------------------
> >>
> >> 4.1. Installation instructions for SLES10
> >>
> >> Note: This is tested on SLES10 SP1. If you have any other version, your
> >> mileage may vary.
> >>
> >> 1. Install the OS in a device that has multiple paths. Make sure the
> >> root device's "Mount by" option is set to "Device by-id" (this option is
> >> available under "expert partitioner" as "fstab options").
> >> 2. Complete the installation. Let the system boot up in multiuser mode.
> >> Make sure the root device, swap device are all referenced by their by-id
> >> device node entries instead of /dev/sd* type names. If they are not, fix
> >> them first.
> >> 3. Once booted, update /etc/multipath.conf If you have to make changes
> >> to /etc/multipath.conf, make the changes.
> >> Note: the option "user_friendly_names" is not supported by initrd.
> >> So, if you have user_friendly_names in your /etc/multipath.conf file,
> >> comment it for now, you can uncomment it later.
> >> 4. Enable multipathing by running the following commands
> >> * chkconfig boot.multipath on
> >>
> >> * chkconfig multipathd on
> >> 5. Add multipath module to initrd
> >>
> >> Edit the file /etc/sysconfig/kernel and add "dm-multipath" to
> >> INITRD_MODULES". Note: If your storage devices needs a hardware handler,
> >> add the corresponding module to INITRD_MODULES, in addition to
> >> "dm-multipath". For example add "dm-rdac" and "dm-multipath" to support
> >> IBM's DS4K storage devices
> >> 6. Run mkinitrd
> >> Note: You can uncomment the user friendly name if you have commented it above.
> >> 7. Reboot
> >>
> >> The system will come up with the root disk on a multipathed device.
> >>
> >> Note: You can switch off multipathing to the root device by adding
> >> multipath=off to the kernel command line.
> >>
> ACK. This is the correct way.
>
> Thanks for writing this up.
>
> Cheers,
>
> Hannes
> --
> Dr. Hannes Reinecke zSeries & Storage
> hare@suse.de +49 911 74053 688
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
> GF: Markus Rex, HRB 16746 (AG Nürnberg)
>
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

RHEL Steps worked perfectly for me but i have a question for SLES installation.

Question. While installing SLES on multipath devices, the second step says:

" 2. Complete the installation. Let the system boot up in multiuser mode.
Make sure the root device, swap device are all referenced by their by-id
device node entries instead of /dev/sd* type names. If they are not, fix
them first."

How do you check that root device and swap device are referenced by their by-id?
And if it is not referenced by the by-id, how do I fix it? Re-install?

Thanks and Regards,
Pradipmaya.


On Dec 19, 2007 1:18 PM, Chandra Seetharaman <sekharan@us.ibm.com> wrote:
> I am working on a multipath usage document. Attached is the installation
> section of that document.
>
> Note that it is written for RHEL5 U1 and SLES10 SP1.
>
> Good Luck,
>
> chandra
>
>
> On Wed, 2007-12-19 at 13:02 -0800, Pradipmaya Maharana wrote:
> > Hi All,
> >
> > Is there a process/document that talks about how to configure
> > root/boot device for multipath?
> >
> > Thanks and Regards,
> > Pradipmaya.
> >
> > --
> > dm-devel mailing list
> > dm-devel@redhat.com
> > https://www.redhat.com/mailman/listinfo/dm-devel
> --
>
> ----------------------------------------------------------------------
> Chandra Seetharaman | Be careful what you choose....
> - sekharan@us.ibm.com | .......you may get it.
> ----------------------------------------------------------------------
>
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Pradipmaya Maharana [pradipmaya@gmail.com] wrote:
> RHEL Steps worked perfectly for me but i have a question for SLES installation.
>
> Question. While installing SLES on multipath devices, the second step says:
>
> " 2. Complete the installation. Let the system boot up in multiuser mode.
> Make sure the root device, swap device are all referenced by their by-id
> device node entries instead of /dev/sd* type names. If they are not, fix
> them first."
>
> How do you check that root device and swap device are referenced by their by-id?
> And if it is not referenced by the by-id, how do I fix it? Re-install?

Look at your grub.conf and see what is there for root and also look at
/etc/fstab and make sure everything there is also ID based.

Malahal.

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

I followed the instruction for SLES, that is, while installing,
selected the option for mounting the device by "device id" but after
reboot mount, fstab shows device names, like /dev/sda2, etc.
What am I missing.

Regards,
Pradipmaya.


On Jan 7, 2008 12:28 PM, <malahal@us.ibm.com> wrote:
> Pradipmaya Maharana [pradipmaya@gmail.com] wrote:
> > RHEL Steps worked perfectly for me but i have a question for SLES installation.
> >
> > Question. While installing SLES on multipath devices, the second step says:
> >
> > " 2. Complete the installation. Let the system boot up in multiuser mode.
> > Make sure the root device, swap device are all referenced by their by-id
> > device node entries instead of /dev/sd* type names. If they are not, fix
> > them first."
> >
> > How do you check that root device and swap device are referenced by their by-id?
> > And if it is not referenced by the by-id, how do I fix it? Re-install?
>
> Look at your grub.conf and see what is there for root and also look at
> /etc/fstab and make sure everything there is also ID based.
>
> Malahal.
>
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Pradipmaya Maharana [pradipmaya@gmail.com] wrote:
> I followed the instruction for SLES, that is, while installing,
> selected the option for mounting the device by "device id" but after
> reboot mount, fstab shows device names, like /dev/sda2, etc.
> What am I missing.

That is odd. You will have to select "device id" for each file system
including swap. I only used 'expert partition' on SLES10 SP1 installs
and it put everything with ID names.

-Malahal.

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

I did exactly what you said for SLES 10.1,
- Create custom partition
- Created partitions for /boot, / and swap of 100MB, 5GB and 1024MB
respectively on /dev/sda. So /dev/sda1 is for "/boot", /dev/sda2 for
"/" and /dev/sda3 for "swap"
- Under fstab option, selected Mount by device-id for each of the partition
- Reboot is fine
- But as I said earlier, mount, fstab, everything shows devcie names, not id

Any way to mount it by device-id?
Is there a way that it can be chaned after installation? Or re-install
is the only way.

Regards,
Pradipmaya.


On Jan 7, 2008 12:46 PM, <malahal@us.ibm.com> wrote:
> Pradipmaya Maharana [pradipmaya@gmail.com] wrote:
> > I followed the instruction for SLES, that is, while installing,
> > selected the option for mounting the device by "device id" but after
> > reboot mount, fstab shows device names, like /dev/sda2, etc.
> > What am I missing.
>
> That is odd. You will have to select "device id" for each file system
> including swap. I only used 'expert partition' on SLES10 SP1 installs
> and it put everything with ID names.
>
> -Malahal.
>
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel

Pradipmaya Maharana [pradipmaya@gmail.com] wrote:
> I did exactly what you said for SLES 10.1,
> - Create custom partition
> - Created partitions for /boot, / and swap of 100MB, 5GB and 1024MB
> respectively on /dev/sda. So /dev/sda1 is for "/boot", /dev/sda2 for
> "/" and /dev/sda3 for "swap"
> - Under fstab option, selected Mount by device-id for each of the partition
> - Reboot is fine
> - But as I said earlier, mount, fstab, everything shows devcie names, not id
>
> Any way to mount it by device-id?
> Is there a way that it can be chaned after installation? Or re-install
> is the only way.

I would just replace sd* names by their equivalent by-id names in fstab
and grub.conf. Do 'ls -l /dev/disk/by-id/*' to get the by-id names
corresponding to your named partitions'

No need to re-install.


-Malahal.

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel