Re: [linux-lvm] kernel panic on lvcreate

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

Hello, 

After some time I revisited this issue on a freshly installed Centos 5.4 box, latest kernel (2.6.18-164.6.1.el5 ) and the panic is still reproducible. Any time I create a snapshot of the root filesystem, kernel panics. The LVM HOWTO says to post bug reports to this list. Is this the proper place?

Thanks, 
Chris

From earlier post:
OOPS message:

BUG: scheduling while atomic: java/0x00000001/2959                               [<c061637f>] <3>BUG: scheduling while atomic: java/0x00000001/2867              [<c061637f>] schedule+0x43/0xa55                                                [<c042c40d>] lock_timer_base+0x15/0x2f
 [<c042c46b>] try_to_del_timer_sync+0x44/0x4a
 [<c0437dd2>] futex_wake+0x3c/0xa5
 [<c0434d5f>] prepare_to_wait+0x24/0x46
 [<c0461ea7>] do_wp_page+0x1b3/0x5bb
 [<c0438b01>] do_futex+0x239/0xb5e
 [<c0434c13>] autoremove_wake_function+0x0/0x2d
 [<c0463876>] __handle_mm_fault+0x9a9/0xa15
 [<c041e727>] default_wake_function+0x0/0xc
 [<c046548d>] unmap_region+0xe1/0xf0
 [<c061954f>] do_page_fault+0x233/0x4e1
 [<c061931c>] do_page_fault+0x0/0x4e1
 [<c0405a89>] error_code+0x39/0x40
 =======================
schedule+0x43/0xa55
 [<c042c40d>] <0>------------[ cut here ]------------
kernel BUG at arch/i386/mm/highmem.c:43!
invalid opcode: 0000 [#1]
SMP
last sysfs file: /devices/pci0000:00/0000:00:00.0/irq
Modules linked in: autofs4 hidp rfcomm l2cap bluetooth lockd sunrpc ip6t_REJECTdCPU:    3 ip6table_filter ip6_tables x_tables ipv6 xfrm_nalgo cry
EIP:    0060:[<c041cb08>]    Not tainted VLI
EFLAGS: 00010206   (2.6.18-164.2.1.el5 #1)
EIP is at kmap_atomic+0x5c/0x7f
eax: c0012d6c   ebx: fff5b000   ecx: c1fb8760   edx: 00000180
esi: f7be8580   edi: f7fa7000   ebp: 00000004   esp: f5c54f0c
ds: 007b   es: 007b   ss: 0068                                                  Process mpath_wait (pid: 3273, ti=f5c54000 task=f5c50000 task.ti=f5c54000)ne    Stack: c073a4e0 c0462f7f f7b0eb30 f7b40780 f5c54f3c 0029c3f0 f63b5ef0 f7be8580
       f7b40780 f7fa7000 00008802 c0472d75 f7b0eb30 f7c299c0 00001000 00001000
       00001000 00000101 00000001 00000000 00000000 f5c5007b 0000007b ffffffff
Call Trace:
 [<c0462f7f>] __handle_mm_fault+0xb2/0xa15
 [<c0472d75>] do_filp_open+0x2b/0x31
 [<c061954f>] do_page_fault+0x233/0x4e1
 [<c061931c>] do_page_fault+0x0/0x4e1
 [<c0405a89>] error_code+0x39/0x40
 =======================
Code: 00 89 e0 25 00 f0 ff ff 6b 50 10 1b 8d 14 13 bb 00 f0 ff ff 8d 42 44 c1 e EIP: [<c041cb08>] kmap_atomic+0x5c/0x7f SS:ESP 0068:f5c54f0c
 <0>Kernel panic - not syncing: Fatal exception

 0c 29 c3 a1 54 12 79 c0 c1 e2 02 29 d0 83 38 00 74 08 <0f> 0b 2b


----- "Milan Broz" <mbroz@redhat.com> wrote:

> On 11/03/2009 04:07 PM, Christopher Hawkins wrote:
> > When I create a root snapshot on a fairly typical Centos 5.3
> server:
> ...
> > I get a kernel panic.
> 
> Please try to first update kernel to version from 5.4.
> (There were some fixes for snapshot like
> https://bugzilla.redhat.com/show_bug.cgi?id=496100)
> 
> If it still fails, please post the OOps trace from kernel (syslog).
> 
> Milan
> --
> mbroz@redhat.com
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Milan Broz]

On 12/09/2009 04:00 PM, Christopher Hawkins wrote:
> 
> After some time I revisited this issue on a freshly installed Centos 5.4 box, latest kernel (2.6.18-164.6.1.el5 )
> and the panic is still reproducible. Any time I create a snapshot of the root filesystem, kernel panics.

I guess it is already reported here https://bugzilla.redhat.com/show_bug.cgi?id=539328
so please watch this bugzilla.

Milan
--
mbroz@redhat.com

Re: [linux-lvm] kernel panic on lvcreate

[Stuart D. Gathman]

On Wed, 9 Dec 2009, Milan Broz wrote:

> > and the panic is still reproducible. Any time I create a snapshot of the root filesystem, kernel panics.
> 
> I guess it is already reported here https://bugzilla.redhat.com/show_bug.cgi?id=539328
> so please watch this bugzilla.

Ah, they are getting it while Oracle is updating.  That supports the updates
during supposedly atomic snapshot theory.

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

Re: [linux-lvm] kernel panic on lvcreate

[Stuart D. Gathman]

On Wed, 9 Dec 2009, Christopher Hawkins wrote:

> After some time I revisited this issue on a freshly installed Centos 5.4 box,
> latest kernel (2.6.18-164.6.1.el5 ) and the panic is still reproducible. Any
> time I create a snapshot of the root filesystem, kernel panics. The LVM HOWTO
> says to post bug reports to this list. Is this the proper place?

Bummer.  I would post the bug on Centos bugzilla also.  Please post the
bug number here if you do it (cause I'll get to it eventually).

Thanks for testing this.  I have the same problem, and have a new client
to install by next year - so not much time to work on it.

Now that we know it is not yet fixed, we can form theories as to what
is going wrong.  My guess is that the problem is caused by the fact that
lvm is updating files in /etc/lvm on the root filesystem while taking
the snapshot.  These updates are done by user space programs, so I would
further speculate that *any* snapshot would crash if an update happened exactly
when creating the snapshot - i.e. the atomic nature of snapshot creation has
been broken.  The lvm user space probably does fsync() on files
in /etc/lvm, which might be involved in triggering the crash.

We could test the first theory by moving /etc/lvm to another volume (I
sometimes put it on /boot - a non LVM filesystem - for easier disaster
recovery.) Naturally, I wouldn't go moving /etc/lvm on a production server.

Testing the second hypothesis is less certain, and would basically involve
trying snapshots of LVs undergoing heavy updating.

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

It is reported here:

https://bugzilla.redhat.com/show_bug.cgi?id=539328

That is definitely the one. And it sounds like they have a potential fix... I have already emailed the developers there asking if I can help test their patch, so hopefully soon I can post back and report status. 

Christopher Hawkins

----- "Stuart D. Gathman" <stuart@bmsi.com> wrote:

> On Wed, 9 Dec 2009, Christopher Hawkins wrote:
> 
> > After some time I revisited this issue on a freshly installed Centos
> 5.4 box,
> > latest kernel (2.6.18-164.6.1.el5 ) and the panic is still
> reproducible. Any
> > time I create a snapshot of the root filesystem, kernel panics. The
> LVM HOWTO
> > says to post bug reports to this list. Is this the proper place?
> 
> Bummer.  I would post the bug on Centos bugzilla also.  Please post
> the
> bug number here if you do it (cause I'll get to it eventually).
> 
> Thanks for testing this.  I have the same problem, and have a new
> client
> to install by next year - so not much time to work on it.
> 
> Now that we know it is not yet fixed, we can form theories as to what
> is going wrong.  My guess is that the problem is caused by the fact
> that
> lvm is updating files in /etc/lvm on the root filesystem while taking
> the snapshot.  These updates are done by user space programs, so I
> would
> further speculate that *any* snapshot would crash if an update
> happened exactly
> when creating the snapshot - i.e. the atomic nature of snapshot
> creation has
> been broken.  The lvm user space probably does fsync() on files
> in /etc/lvm, which might be involved in triggering the crash.
> 
> We could test the first theory by moving /etc/lvm to another volume
> (I
> sometimes put it on /boot - a non LVM filesystem - for easier
> disaster
> recovery.) Naturally, I wouldn't go moving /etc/lvm on a production
> server.
> 
> Testing the second hypothesis is less certain, and would basically
> involve
> trying snapshots of LVs undergoing heavy updating.
> 
> -- 
> 	      Stuart D. Gathman <stuart@bmsi.com>
>     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703
> 591-6154
> "Confutatis maledictis, flammis acribus addictis" - background song
> for
> a Microsoft sponsored "Where do you want to go from here?"
> commercial.
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

There is a working patch for this issue in kernel-2.6.18-178.el5. If anyone needs it sooner, they do have a test kernel available for download. 

Christopher Hawkins

----- "Christopher Hawkins" <chawkins@bplinux.com> wrote:

> It is reported here:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=539328
> 
> That is definitely the one. And it sounds like they have a potential
> fix... I have already emailed the developers there asking if I can
> help test their patch, so hopefully soon I can post back and report
> status. 
> 
> Christopher Hawkins
> 
> ----- "Stuart D. Gathman" <stuart@bmsi.com> wrote:
> 
> > On Wed, 9 Dec 2009, Christopher Hawkins wrote:
> > 
> > > After some time I revisited this issue on a freshly installed
> Centos
> > 5.4 box,
> > > latest kernel (2.6.18-164.6.1.el5 ) and the panic is still
> > reproducible. Any
> > > time I create a snapshot of the root filesystem, kernel panics.
> The
> > LVM HOWTO
> > > says to post bug reports to this list. Is this the proper place?
> > 
> > Bummer.  I would post the bug on Centos bugzilla also.  Please post
> > the
> > bug number here if you do it (cause I'll get to it eventually).
> > 
> > Thanks for testing this.  I have the same problem, and have a new
> > client
> > to install by next year - so not much time to work on it.
> > 
> > Now that we know it is not yet fixed, we can form theories as to
> what
> > is going wrong.  My guess is that the problem is caused by the fact
> > that
> > lvm is updating files in /etc/lvm on the root filesystem while
> taking
> > the snapshot.  These updates are done by user space programs, so I
> > would
> > further speculate that *any* snapshot would crash if an update
> > happened exactly
> > when creating the snapshot - i.e. the atomic nature of snapshot
> > creation has
> > been broken.  The lvm user space probably does fsync() on files
> > in /etc/lvm, which might be involved in triggering the crash.
> > 
> > We could test the first theory by moving /etc/lvm to another volume
> > (I
> > sometimes put it on /boot - a non LVM filesystem - for easier
> > disaster
> > recovery.) Naturally, I wouldn't go moving /etc/lvm on a production
> > server.
> > 
> > Testing the second hypothesis is less certain, and would basically
> > involve
> > trying snapshots of LVs undergoing heavy updating.
> > 
> > -- 
> > 	      Stuart D. Gathman <stuart@bmsi.com>
> >     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703
> > 591-6154
> > "Confutatis maledictis, flammis acribus addictis" - background song
> > for
> > a Microsoft sponsored "Where do you want to go from here?"
> > commercial.
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

I have not, but I can within a few hours. Will post the results.

Christopher Hawkins

----- "Stuart D. Gathman" <stuart@bmsi.com> wrote:

> On Wed, 4 Nov 2009, Stuart D. Gathman wrote:
> 

> Anyone tested the new 164.6.1 kernel release to see if this crasher is
> fixed?
> The changelog doesn't mention anything that sounds like it. 
> (Regressions
> are usually fixed quickly.)
> 
> Has this been reported?  If 164.6.1 still has the problem, I can work
> on a bug report.
> 
> -- 
> 	      Stuart D. Gathman <stuart@bmsi.com>
>     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703
> 591-6154
> "Confutatis maledictis, flammis acribus addictis" - background song
> for
> a Microsoft sponsored "Where do you want to go from here?"
> commercial.
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

Updated to 2.6.18-164.6.1.el5, same crash. Stuart, can you post a link to your bug report if you do one? And if not, please let me know and I will work on one. 

Thanks!

Christopher Hawkins

----- "Christopher Hawkins" <chawkins@bplinux.com> wrote:

> I have not, but I can within a few hours. Will post the results.
> 
> Christopher Hawkins
> 
> ----- "Stuart D. Gathman" <stuart@bmsi.com> wrote:
> 
> > On Wed, 4 Nov 2009, Stuart D. Gathman wrote:
> > 
> 
> > Anyone tested the new 164.6.1 kernel release to see if this crasher
> is
> > fixed?
> > The changelog doesn't mention anything that sounds like it. 
> > (Regressions
> > are usually fixed quickly.)
> > 
> > Has this been reported?  If 164.6.1 still has the problem, I can
> work
> > on a bug report.
> > 
> > -- 
> > 	      Stuart D. Gathman <stuart@bmsi.com>
> >     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703
> > 591-6154
> > "Confutatis maledictis, flammis acribus addictis" - background song
> > for
> > a Microsoft sponsored "Where do you want to go from here?"
> > commercial.
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

Actually it looks like the reverse might be true. I tried this on a box with older kernel 2.6.18-92.1.22.el5 and there is no panic. I upgraded that box to kernel 2.6.18-164.2.1.el5, reboot, and now the panic is reproducible. Trying to get an oops, will post again soon. 

Christopher Hawkins

----- "Milan Broz" <mbroz@redhat.com> wrote:

> On 11/03/2009 04:07 PM, Christopher Hawkins wrote:
> > When I create a root snapshot on a fairly typical Centos 5.3
> server:
> ...
> > I get a kernel panic.
> 
> Please try to first update kernel to version from 5.4.
> (There were some fixes for snapshot like
> https://bugzilla.redhat.com/show_bug.cgi?id=496100)
> 
> If it still fails, please post the OOps trace from kernel (syslog).
> 
> Milan
> --
> mbroz@redhat.com
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

The EIP at kmap_atomic has been in every one of these that I have seen. Let me know if there's anything else I can do...

OOPS message:

BUG: scheduling while atomic: java/0x00000001/2959                               [<c061637f>] <3>BUG: scheduling while atomic: java/0x00000001/2867              [<c061637f>] schedule+0x43/0xa55                                                [<c042c40d>] lock_timer_base+0x15/0x2f
 [<c042c46b>] try_to_del_timer_sync+0x44/0x4a
 [<c0437dd2>] futex_wake+0x3c/0xa5
 [<c0434d5f>] prepare_to_wait+0x24/0x46
 [<c0461ea7>] do_wp_page+0x1b3/0x5bb
 [<c0438b01>] do_futex+0x239/0xb5e
 [<c0434c13>] autoremove_wake_function+0x0/0x2d
 [<c0463876>] __handle_mm_fault+0x9a9/0xa15
 [<c041e727>] default_wake_function+0x0/0xc
 [<c046548d>] unmap_region+0xe1/0xf0
 [<c061954f>] do_page_fault+0x233/0x4e1
 [<c061931c>] do_page_fault+0x0/0x4e1
 [<c0405a89>] error_code+0x39/0x40
 =======================
schedule+0x43/0xa55
 [<c042c40d>] <0>------------[ cut here ]------------
kernel BUG at arch/i386/mm/highmem.c:43!
invalid opcode: 0000 [#1]
SMP
last sysfs file: /devices/pci0000:00/0000:00:00.0/irq
Modules linked in: autofs4 hidp rfcomm l2cap bluetooth lockd sunrpc ip6t_REJECTdCPU:    3 ip6table_filter ip6_tables x_tables ipv6 xfrm_nalgo cry
EIP:    0060:[<c041cb08>]    Not tainted VLI
EFLAGS: 00010206   (2.6.18-164.2.1.el5 #1)
EIP is at kmap_atomic+0x5c/0x7f
eax: c0012d6c   ebx: fff5b000   ecx: c1fb8760   edx: 00000180
esi: f7be8580   edi: f7fa7000   ebp: 00000004   esp: f5c54f0c
ds: 007b   es: 007b   ss: 0068                                                  Process mpath_wait (pid: 3273, ti=f5c54000 task=f5c50000 task.ti=f5c54000)ne    Stack: c073a4e0 c0462f7f f7b0eb30 f7b40780 f5c54f3c 0029c3f0 f63b5ef0 f7be8580
       f7b40780 f7fa7000 00008802 c0472d75 f7b0eb30 f7c299c0 00001000 00001000
       00001000 00000101 00000001 00000000 00000000 f5c5007b 0000007b ffffffff
Call Trace:
 [<c0462f7f>] __handle_mm_fault+0xb2/0xa15
 [<c0472d75>] do_filp_open+0x2b/0x31
 [<c061954f>] do_page_fault+0x233/0x4e1
 [<c061931c>] do_page_fault+0x0/0x4e1
 [<c0405a89>] error_code+0x39/0x40
 =======================
Code: 00 89 e0 25 00 f0 ff ff 6b 50 10 1b 8d 14 13 bb 00 f0 ff ff 8d 42 44 c1 e EIP: [<c041cb08>] kmap_atomic+0x5c/0x7f SS:ESP 0068:f5c54f0c
 <0>Kernel panic - not syncing: Fatal exception

 0c 29 c3 a1 54 12 79 c0 c1 e2 02 29 d0 83 38 00 74 08 <0f> 0b 2b


----- "Christopher Hawkins" <chawkins@bplinux.com> wrote:

> Actually it looks like the reverse might be true. I tried this on a
> box with older kernel 2.6.18-92.1.22.el5 and there is no panic. I
> upgraded that box to kernel 2.6.18-164.2.1.el5, reboot, and now the
> panic is reproducible. Trying to get an oops, will post again soon. 
> 
> Christopher Hawkins
> 
> ----- "Milan Broz" <mbroz@redhat.com> wrote:
> 
> > On 11/03/2009 04:07 PM, Christopher Hawkins wrote:
> > > When I create a root snapshot on a fairly typical Centos 5.3
> > server:
> > ...
> > > I get a kernel panic.
> > 
> > Please try to first update kernel to version from 5.4.
> > (There were some fixes for snapshot like
> > https://bugzilla.redhat.com/show_bug.cgi?id=496100)
> > 
> > If it still fails, please post the OOps trace from kernel (syslog).
> > 
> > Milan
> > --
> > mbroz@redhat.com
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] kernel panic on lvcreate

[Stuart D. Gathman]

On Tue, 3 Nov 2009, Christopher Hawkins wrote:

> Actually it looks like the reverse might be true. I tried this on a box with
> older kernel 2.6.18-92.1.22.el5 and there is no panic. I upgraded that box to
> kernel 2.6.18-164.2.1.el5, reboot, and now the panic is reproducible. Trying
> to get an oops, will post again soon. 

I believe I am getting the same thing.  An lvcreate -s ... on the root
filesystem of dom0 causes a kernel panic.  This happened at 5:30am via cron.
This has been working for years, and seems to have started when we rebooted to
load kernel-xen-2.6.18-164.el5.  After the crash, the BIOS was unable to
respond to the soft power button, and the system required a hard poweroff.
Unfortunately, the person on site this morning didn't get anything from the
console.  Just like the OP, the snapshot is created after the reboot, BUT not
attached to the origin.  The snapsnot causing the crash was c5_SNAP below:

# lvs
  LV       VG      Attr   LSize   Origin Snap%  Move Log Copy%  Convert
  backup   backvg6 -wi-ao 232.88G                                      
  BWI      rootvg  -wi-a-  20.00G                                      
  C4       rootvg  -wi-ao  30.00G                                      
  C4_SWAP  rootvg  -wi-ao 512.00M                                      
  CentOS5  rootvg  -wi-a-   9.75G                                      
  DFL      rootvg  -wi-a-  10.00G                                      
  DFL_SWAP rootvg  -wi-a- 512.00M                                      
  GEN      rootvg  -wi-a-  10.00G                                      
  GENSWAP  rootvg  -wi-a- 512.00M                                      
  SPAN     rootvg  -wi-a-  30.00G                                      
  SPD      rootvg  -wi-ao  20.00G                                      
  SPD_SWAP rootvg  -wi-ao 512.00M                                      
  USEXP    rootvg  -wi-a-  10.00G                                      
  c5       rootvg  -wi-ao  40.00G                                      
  c5_SNAP  rootvg  -wi-a-   2.00G                                      
  c5_swap  rootvg  -wi-ao   2.00G      
# rpm -q kernel-xen lvm2
kernel-xen-2.6.18-164.el5
lvm2-2.02.46-8.el5
# diff backup/rootvg archive/rootvg_01566.vg
6c6
< description = "Created *after* executing '/usr/sbin/lvcreate -s -L 2G -n c5_SNAP /dev/rootvg/c5'"
---
> description = "Created *before* executing '/usr/sbin/lvcreate -s -L 2G -n c5_SNAP /dev/rootvg/c5'"
13c13
<       seqno = 2340
---
>       seqno = 2339
345,363d344
< 
<               c5_SNAP {
<                       id = "vdbcj3-1E3H-5ywU-QSJ8-M3W6-dLbj-FDr035"
<                       status = ["READ", "WRITE", "VISIBLE"]
<                       flags = []
<                       segment_count = 1
< 
<                       segment1 {
<                               start_extent = 0
<                               extent_count = 64       # 2 Gigabytes
< 
<                               type = "striped"
<                               stripe_count = 1        # linear
< 
<                               stripes = [
<                                       "pv3", 1920
<                               ]
<                       }
<               }

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

Re: [linux-lvm] kernel panic on lvcreate

[Stuart D. Gathman]

On Wed, 4 Nov 2009, Stuart D. Gathman wrote:

> On Tue, 3 Nov 2009, Christopher Hawkins wrote:
> 
> > Actually it looks like the reverse might be true. I tried this on a box with
> > older kernel 2.6.18-92.1.22.el5 and there is no panic. I upgraded that box to
> > kernel 2.6.18-164.2.1.el5, reboot, and now the panic is reproducible. Trying
> > to get an oops, will post again soon. 
> 
> I believe I am getting the same thing.  An lvcreate -s ... on the root
> filesystem of dom0 causes a kernel panic.  This happened at 5:30am via cron.

Anyone tested the new 164.6.1 kernel release to see if this crasher is fixed?
The changelog doesn't mention anything that sounds like it.  (Regressions
are usually fixed quickly.)

Has this been reported?  If 164.6.1 still has the problem, I can work
on a bug report.

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

[linux-lvm] kernel panic on lvcreate

[Christopher Hawkins]

Hoping there's a quick answer to this issue and that I'm doing something wrong. Have verified this on 2 machines now, trying a third shortly. When I create a root snapshot on a fairly typical Centos 5.3 server:
lvcreate -s --size=500M --name=LogVol00_snapshot /dev/VolGroup00/LogVol00

then remove it:
lvremove /dev/VolGroup00/LogVol00_snapshot

then create another one later:
lvcreate -s --size=500M --name=LogVol00_snapshot /dev/VolGroup00/LogVol00

I get a kernel panic. The server reboots ok, no issues with corrupt volumes. And the snapshot does exist after the reboot, so it looks like it is getting created ok before the panic stops the machine. Interestingly, lvcreate can create a regular LV without a panic and also a snapshot of another volume, but not another snapshot of the root volume. 

BUT, if I rmeove the snapshot, reboot, and THEN create another root snapshot, it completes without errors. Any ideas on how to flush out lvm2 and manually do whatever is happening on reboot so I can create and remove snapshots without power cycling?

Thanks List!!
  
Christopher Hawkins

Re: [linux-lvm] kernel panic on lvcreate

[Milan Broz]

On 11/03/2009 04:07 PM, Christopher Hawkins wrote:
> When I create a root snapshot on a fairly typical Centos 5.3 server:
...
> I get a kernel panic.

Please try to first update kernel to version from 5.4.
(There were some fixes for snapshot like
https://bugzilla.redhat.com/show_bug.cgi?id=496100)

If it still fails, please post the OOps trace from kernel (syslog).

Milan
--
mbroz@redhat.com