[gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Mark Knecht]

Hi,
   I don't think this is likely to be a Gentoo issue but I figured I'd
ask here first before going elsewhere. (LKML, linux-raid, elsewhere)
Additionally it's not a critical problem at all but rather something
I'd like to try and understand and then report if appropriate.

   On my main i7-980x machine I've been wanting to move root away from
an old 3-disk 50GB RAID1 that I built first built the machine with to
a newer 150GB RAID6. Toward this end the machine has two complete
Gentoo builds on it:

c2stable ~ # cat /proc/mdstat
<SNIP>

md3 : active raid6 sdc3[1] sdd3[2] sdb3[0] sde3[3] sdf3[5]
      157305168 blocks super 1.2 level 6, 16k chunk, algorithm 2 [5/5] [UUUUU]

md126 : active raid1 sdd5[2] sdc5[1] sdb5[0]
      52436032 blocks [3/3] [UUU]

unused devices: <none>
c2stable ~ #

md126 is the older RAID1, md3 is the newer RAID6. The are both built
on parts of the 5 hard drives in the box.

The two builds are intended to be identical. Same packages installed,
same kernel with the only exception being the RAID6 uses an initramfs
built into it. A diff of the two kernel configs shows only that
difference:

c2stable ~ # diff /usr/src/linux/.config /mnt/newRAID6/usr/src/linux/.config
137c137,139
< CONFIG_INITRAMFS_SOURCE=""
---
> CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs.config"
> CONFIG_INITRAMFS_ROOT_UID=0
> CONFIG_INITRAMFS_ROOT_GID=0
142a145,146
> CONFIG_INITRAMFS_COMPRESSION_NONE=y
> # CONFIG_INITRAMFS_COMPRESSION_GZIP is not set
c2stable ~ #

   In my grub.conf file I have three methods of booting the machine.
There are two methods of booting the RAID1 config, using the device
name and using the label. For the RAID6 I have only the label method:

(NOTE: Snipped out backup kernels just to clarify)

c2stable ~ # cat /boot/grub/grub.conf
default 0
timeout 15
splashimage=(hd0,0)/boot/grub/splash.xpm.gz

title RAID1 3.6.11-gentoo
root (hd0,0)
kernel (hd0,0)/boot/bzImage-3.6.11-gentoo root=/dev/md126

title RAID1 3.6.11-gentoo using LABEL
root (hd0,0)
kernel (hd0,0)/boot/bzImage-3.6.11-gentoo root=LABEL=RAID1root

title RAID6 3.6.11-gentoo using LABEL
root (hd0,0)
kernel (hd0,0)/boot/bzImage-RAID6-3.6.11-gentoo root=LABEL=RAID6root

c2stable ~ #

c2stable ~ # e2label /dev/md126
RAID1root
c2stable ~ # e2label /dev/md3
RAID6root
c2stable ~ #


The results are:

1) RAID1 using md126 boots fine
2) RAID1 using label of RAID1root fails
3) RAID6 using label of RAID6root boots fine

   The failure is a kernel crash before the machine gets very far so
the only capture I might be able to try is with a camera and then post
that on line, but the screen is 80x25 and it's just a kernel crash so
there's very little data on the screen when the machine dies.

   I've been Googling around for a couple of days but haven't found
anything very interesting. I figured I'd ask here first just to see
what ideas come up.

Thanks,
Mark

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[J. Roeleveld]

Mark Knecht <markknecht@gmail.com> wrote:

>Hi,
>   I don't think this is likely to be a Gentoo issue but I figured I'd
>ask here first before going elsewhere. (LKML, linux-raid, elsewhere)
>Additionally it's not a critical problem at all but rather something
>I'd like to try and understand and then report if appropriate.
>
>   On my main i7-980x machine I've been wanting to move root away from
>an old 3-disk 50GB RAID1 that I built first built the machine with to
>a newer 150GB RAID6. Toward this end the machine has two complete
>Gentoo builds on it:
>
>c2stable ~ # cat /proc/mdstat
><SNIP>
>
>md3 : active raid6 sdc3[1] sdd3[2] sdb3[0] sde3[3] sdf3[5]
>157305168 blocks super 1.2 level 6, 16k chunk, algorithm 2 [5/5]
>[UUUUU]
>
>md126 : active raid1 sdd5[2] sdc5[1] sdb5[0]
>      52436032 blocks [3/3] [UUU]
>
>unused devices: <none>
>c2stable ~ #
>
>md126 is the older RAID1, md3 is the newer RAID6. The are both built
>on parts of the 5 hard drives in the box.
>
>The two builds are intended to be identical. Same packages installed,
>same kernel with the only exception being the RAID6 uses an initramfs
>built into it. A diff of the two kernel configs shows only that
>difference:
>
>c2stable ~ # diff /usr/src/linux/.config
>/mnt/newRAID6/usr/src/linux/.config
>137c137,139
>< CONFIG_INITRAMFS_SOURCE=""
>---
>> CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs.config"
>> CONFIG_INITRAMFS_ROOT_UID=0
>> CONFIG_INITRAMFS_ROOT_GID=0
>142a145,146
>> CONFIG_INITRAMFS_COMPRESSION_NONE=y
>> # CONFIG_INITRAMFS_COMPRESSION_GZIP is not set
>c2stable ~ #
>
>   In my grub.conf file I have three methods of booting the machine.
>There are two methods of booting the RAID1 config, using the device
>name and using the label. For the RAID6 I have only the label method:
>
>(NOTE: Snipped out backup kernels just to clarify)
>
>c2stable ~ # cat /boot/grub/grub.conf
>default 0
>timeout 15
>splashimage=(hd0,0)/boot/grub/splash.xpm.gz
>
>title RAID1 3.6.11-gentoo
>root (hd0,0)
>kernel (hd0,0)/boot/bzImage-3.6.11-gentoo root=/dev/md126
>
>title RAID1 3.6.11-gentoo using LABEL
>root (hd0,0)
>kernel (hd0,0)/boot/bzImage-3.6.11-gentoo root=LABEL=RAID1root
>
>title RAID6 3.6.11-gentoo using LABEL
>root (hd0,0)
>kernel (hd0,0)/boot/bzImage-RAID6-3.6.11-gentoo root=LABEL=RAID6root
>
>c2stable ~ #
>
>c2stable ~ # e2label /dev/md126
>RAID1root
>c2stable ~ # e2label /dev/md3
>RAID6root
>c2stable ~ #
>
>
>The results are:
>
>1) RAID1 using md126 boots fine
>2) RAID1 using label of RAID1root fails
>3) RAID6 using label of RAID6root boots fine
>
>   The failure is a kernel crash before the machine gets very far so
>the only capture I might be able to try is with a camera and then post
>that on line, but the screen is 80x25 and it's just a kernel crash so
>there's very little data on the screen when the machine dies.
>
>   I've been Googling around for a couple of days but haven't found
>anything very interesting. I figured I'd ask here first just to see
>what ideas come up.
>
>Thanks,
>Mark

Mark.

I seem to remember that to be able to use LABEL for the root= line requires an init* as you need userspace utilities to read the labels.

You could try the UUIDs instead. But I am not sure if that might work.

HTH

Joost

PS. All the best for 2013!
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Mark Knecht]

On Mon, Dec 31, 2012 at 12:53 PM, J. Roeleveld <joost@antarean.org> wrote:
> Mark Knecht <markknecht@gmail.com> wrote:
<SNIP>
>
> Mark.
>
> I seem to remember that to be able to use LABEL for the root= line requires an init* as you need userspace utilities to read the labels.
>
> You could try the UUIDs instead. But I am not sure if that might work.
>
> HTH
>
> Joost
>
> PS. All the best for 2013!
> --
> Sent from my Android phone with K-9 Mail. Please excuse my brevity.
>

I don't know if you're right but it makes sense. If I need e2label to
read labels from the CLI then I probably need all the same stuff in
the initramfs which this one doesn't have.

The problem I have with that idea is that all I put in the RAID6 which
does have an initramfs is e2fsck, not e2label or anything else.
However maybe e2fsck has that capability and that's why it's working?

Good catch!

Thanks, and best wishes for the new year and a safe New Year's eve to all.

Cheers,
Mark

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[J. Roeleveld]

Mark Knecht <markknecht@gmail.com> wrote:

>On Mon, Dec 31, 2012 at 12:53 PM, J. Roeleveld <joost@antarean.org>
>wrote:
>> Mark Knecht <markknecht@gmail.com> wrote:
><SNIP>
>>
>> Mark.
>>
>> I seem to remember that to be able to use LABEL for the root= line
>requires an init* as you need userspace utilities to read the labels.
>>
>> You could try the UUIDs instead. But I am not sure if that might
>work.
>>
>> HTH
>>
>> Joost
>>
>> PS. All the best for 2013!
>> --
>> Sent from my Android phone with K-9 Mail. Please excuse my brevity.
>>
>
>I don't know if you're right but it makes sense. If I need e2label to
>read labels from the CLI then I probably need all the same stuff in
>the initramfs which this one doesn't have.
>
>The problem I have with that idea is that all I put in the RAID6 which
>does have an initramfs is e2fsck, not e2label or anything else.
>However maybe e2fsck has that capability and that's why it's working?
>
>Good catch!
>
>Thanks, and best wishes for the new year and a safe New Year's eve to
>all.
>
>Cheers,
>Mark

Mark.

I think there was a thread about this earlier this year when people started noticing sda/hda changes.
As I don't have access to my desktop at the moment. I can't check.

Good luck with it.

--
Joost
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Bruce Hill]

On Mon, Dec 31, 2012 at 02:09:35PM -0800, Mark Knecht wrote:
> 
> I don't know if you're right but it makes sense. If I need e2label to
> read labels from the CLI then I probably need all the same stuff in
> the initramfs which this one doesn't have.
> 
> The problem I have with that idea is that all I put in the RAID6 which
> does have an initramfs is e2fsck, not e2label or anything else.
> However maybe e2fsck has that capability and that's why it's working?
> 
> Good catch!
> 
> Thanks, and best wishes for the new year and a safe New Year's eve to all.
> 
> Cheers,
> Mark

I've deleted your OP (sorry), but also, the kernel autodetects RAID using
metadata 0.90 superblocks, but not 1.2 superblock (seems your output had some
of each?).
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Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Mark Knecht]

On Mon, Dec 31, 2012 at 2:28 PM, Bruce Hill
<daddy@happypenguincomputers.com> wrote:
> On Mon, Dec 31, 2012 at 02:09:35PM -0800, Mark Knecht wrote:
>>
>> I don't know if you're right but it makes sense. If I need e2label to
>> read labels from the CLI then I probably need all the same stuff in
>> the initramfs which this one doesn't have.
>>
>> The problem I have with that idea is that all I put in the RAID6 which
>> does have an initramfs is e2fsck, not e2label or anything else.
>> However maybe e2fsck has that capability and that's why it's working?
>>
>> Good catch!
>>
>> Thanks, and best wishes for the new year and a safe New Year's eve to all.
>>
>> Cheers,
>> Mark
>
> I've deleted your OP (sorry), but also, the kernel autodetects RAID using
> metadata 0.90 superblocks, but not 1.2 superblock (seems your output had some
> of each?).
> --

Hi Bruce,
   Yes, in the first and older Gentoo build I'm letting the kernel
autodetect RAID1 to find /. That's the install that does NOT work
mounting by label.

   In the second install I use an initramfs, / is on a RAID6 and is
not autodetected. Rather I assemble the RAID6 within the initramfs
using mdadm --assemble ####. The initramfs has both e2fsck & mdadm so
it's able to assemble the RAID. It's also able to mount by label
without any problems.

   Joost is suggesting that there might have been a thread earlier
this year that said you must use an initramfs to mount by label, but I
cannot find any grub documentation that supports that, and so far have
not discovered the thread he's remembering.

HTH, and thanks!
Mark

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[J. Roeleveld]

Mark Knecht <markknecht@gmail.com> wrote:

>On Mon, Dec 31, 2012 at 2:28 PM, Bruce Hill
><daddy@happypenguincomputers.com> wrote:
>> On Mon, Dec 31, 2012 at 02:09:35PM -0800, Mark Knecht wrote:
>>>
>>> I don't know if you're right but it makes sense. If I need e2label
>to
>>> read labels from the CLI then I probably need all the same stuff in
>>> the initramfs which this one doesn't have.
>>>
>>> The problem I have with that idea is that all I put in the RAID6
>which
>>> does have an initramfs is e2fsck, not e2label or anything else.
>>> However maybe e2fsck has that capability and that's why it's
>working?
>>>
>>> Good catch!
>>>
>>> Thanks, and best wishes for the new year and a safe New Year's eve
>to all.
>>>
>>> Cheers,
>>> Mark
>>
>> I've deleted your OP (sorry), but also, the kernel autodetects RAID
>using
>> metadata 0.90 superblocks, but not 1.2 superblock (seems your output
>had some
>> of each?).
>> --
>
>Hi Bruce,
>   Yes, in the first and older Gentoo build I'm letting the kernel
>autodetect RAID1 to find /. That's the install that does NOT work
>mounting by label.
>
>   In the second install I use an initramfs, / is on a RAID6 and is
>not autodetected. Rather I assemble the RAID6 within the initramfs
>using mdadm --assemble ####. The initramfs has both e2fsck & mdadm so
>it's able to assemble the RAID. It's also able to mount by label
>without any problems.
>
>   Joost is suggesting that there might have been a thread earlier
>this year that said you must use an initramfs to mount by label, but I
>cannot find any grub documentation that supports that, and so far have
>not discovered the thread he's remembering.
>
>HTH, and thanks!
>Mark

Found it.

Topic: [gentoo-user] Gentoo Installation, Kernel Panic

Was around 20th of July.


-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Mark Knecht]

On Mon, Dec 31, 2012 at 2:59 PM, J. Roeleveld <joost@antarean.org> wrote:
> Gentoo Installation, Kernel Panic

OK, thanks. Yes, in the last post of that thread Nilesh states

"Since I use grub2-mkconfig to generate the configuration, it's there
with UUID, but it works with LABEL as well, I have tried it.
Also, *don't* build your kernel *without* initramfs, because the
kernel by default doesn't support mounting by LABELs or UUIDs (I think
so, I've had failures w/o initrd)."

While I don't know Nilesh's background, I have no reason to really
doubt what he says here I seem to find a lot of posts on the web where
people mount using UUID and they aren't clear as to whether they have
an initramfs or not.

I'll consider this solved for now with one caveat that it's unclear
when you build the initramfs what tools have to be placed within it to
make the following true.

1) No initramfs - mount by device name only

2) With initramfs - mount by device name, label or UUID.

Thanks VERY MUCH for taking the time to find this. I'm removing the
offending option from my grub.config file.

Cheers,
Mark

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Dustin C. Hatch]

On 12/31/2012 17:10, Mark Knecht wrote:
> On Mon, Dec 31, 2012 at 2:59 PM, J. Roeleveld <joost@antarean.org> wrote:
>> Gentoo Installation, Kernel Panic
>
> OK, thanks. Yes, in the last post of that thread Nilesh states
>
> "Since I use grub2-mkconfig to generate the configuration, it's there
> with UUID, but it works with LABEL as well, I have tried it.
> Also, *don't* build your kernel *without* initramfs, because the
> kernel by default doesn't support mounting by LABELs or UUIDs (I think
> so, I've had failures w/o initrd)."
>
> While I don't know Nilesh's background, I have no reason to really
> doubt what he says here I seem to find a lot of posts on the web where
> people mount using UUID and they aren't clear as to whether they have
> an initramfs or not.
>
> I'll consider this solved for now with one caveat that it's unclear
> when you build the initramfs what tools have to be placed within it to
> make the following true.
>
> 1) No initramfs - mount by device name only
>
> 2) With initramfs - mount by device name, label or UUID.
>
> Thanks VERY MUCH for taking the time to find this. I'm removing the
> offending option from my grub.config file.
>
> Cheers,
> Mark
>

The other wiki has a page[1] about building an initramfs that includes a 
section on writing a linuxrc script to support exactly that. I have 
since switched to Genkernel, but I used to have a hand-built initramfs 
containing very little besides that script block.

[1] http://en.gentoo-wiki.com/wiki/Initramfs#UUID.2FLABEL_Root_Mounting

-- 
♫Dustin

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[Mark Knecht]

On Tue, Jan 1, 2013 at 7:23 AM, Dustin C. Hatch <admiralnemo@gmail.com> wrote:


> The other wiki has a page[1] about building an initramfs that includes a
> section on writing a linuxrc script to support exactly that. I have since
> switched to Genkernel, but I used to have a hand-built initramfs containing
> very little besides that script block.
>
> [1] http://en.gentoo-wiki.com/wiki/Initramfs#UUID.2FLABEL_Root_Mounting
>
> --
> ♫Dustin
>

Thanks Dustin,
   I saw that entry but read it a bit differently. I took it to mean
that if you want BOTH label and UUID as methods then you have to parse
what's on the device to determine whether what's there is a label or a
UUID.

   In any case, I'd have to have an initramfs to use it so I believe
that's consistent with the outcome from yesterday's conversation.

   Thanks for providing the link.

Cheers,
Mark

Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root

[covici]

Mark Knecht <markknecht@gmail.com> wrote:

> On Mon, Dec 31, 2012 at 2:28 PM, Bruce Hill
> <daddy@happypenguincomputers.com> wrote:
> > On Mon, Dec 31, 2012 at 02:09:35PM -0800, Mark Knecht wrote:
> >>
> >> I don't know if you're right but it makes sense. If I need e2label to
> >> read labels from the CLI then I probably need all the same stuff in
> >> the initramfs which this one doesn't have.
> >>
> >> The problem I have with that idea is that all I put in the RAID6 which
> >> does have an initramfs is e2fsck, not e2label or anything else.
> >> However maybe e2fsck has that capability and that's why it's working?
> >>
> >> Good catch!
> >>
> >> Thanks, and best wishes for the new year and a safe New Year's eve to all.
> >>
> >> Cheers,
> >> Mark
> >
> > I've deleted your OP (sorry), but also, the kernel autodetects RAID using
> > metadata 0.90 superblocks, but not 1.2 superblock (seems your output had some
> > of each?).
> > --
> 
> Hi Bruce,
>    Yes, in the first and older Gentoo build I'm letting the kernel
> autodetect RAID1 to find /. That's the install that does NOT work
> mounting by label.
> 
>    In the second install I use an initramfs, / is on a RAID6 and is
> not autodetected. Rather I assemble the RAID6 within the initramfs
> using mdadm --assemble ####. The initramfs has both e2fsck & mdadm so
> it's able to assemble the RAID. It's also able to mount by label
> without any problems.
> 
>    Joost is suggesting that there might have been a thread earlier
> this year that said you must use an initramfs to mount by label, but I
> cannot find any grub documentation that supports that, and so far have
> not discovered the thread he's remembering.

I know you need at least proc to get the label, so maybe the init ramfs
will have /proc.

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici@ccs.covici.com