LVM Oops
Hello!
Oops happened after several days of normal operation diring snapshot.
Linux backup-db2 2.4.27 #1 SMP Fri Oct 22 05:22:55 EST 2004 i686 unknown unknown GNU/Linux
Filesystem - reiserfs.
Logical Volume Manager 1.0.8
Heinz Mauelshagen, Sistina Software 17/11/2003 (IOP 10)
Unable to handle kernel NULL pointer dereference at virtual address 00000004 c02adbea *pde = 126d9001 Oops: 0002 CPU: 0 EIP: 0010:[<c02adbea>] Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00010202
eax: f8c3b4b0 ebx: fb20bde8 ecx: f89edc38 edx: 00000000
esi: 33dbdf00 edi: 00000001 ebp: 00000803 esp: c5bc3dac
ds: 0018 es: 0018 ss: 0018
Process kupdated (pid: 9, stackpage=c5bc3000)
Stack: 00000038 00000803 00000000 eae59400 f4ff7800 f4ff7970 00002000 c02aa5fa
c5bc3e00 c5bc3df8 33dbc580 f4ff7800 f73a9000 00000400 f77db240
eae59570
f73a9000 33dbc580 0002cdd0 33dbdf38 33dbdf38 08030803 00003a06
f2046d00
Call Trace: [<c02aa5fa>] [<c02aa727>] [<c022a4be>] [<c022a59e>] [<c02b8d08>]
[<c013ebdc>] [<c013ece5>] [<c0142b48>] [<c0142e41>] [<c01072b6>]
[<c0142d50>]
[<c0105000>] [<c01057ae>] [<c0142d50>]
Code: 89 42 04 8b 03 89 48 04 89 01 89 59 04 89 0b 89 ca 90 8d 74Quoted 1 line
Quoted 1 line
EIP;
c02adbea<lvm_snapshot_remap_block+aa/100> <=====
Trace; c02aa5fa <lvm_map+36a/480>
Trace; c02aa727 <lvm_make_request_fn+17/30>
Trace; c022a4be <generic_make_request+be/140>
Trace; c022a59e <submit_bh+5e/130>
Trace; c02b8d08 <netif_receive_skb+188/1c0>
Trace; c013ebdc <write_locked_buffers+2c/40>
Trace; c013ece5 <write_some_buffers+f5/140>
Trace; c0142b48 <sync_old_buffers+78/b0>
Trace; c0142e41 <kupdate+f1/1c0>
Trace; c01072b6 <ret_from_fork+6/20>
Trace; c0142d50 <kupdate+0/1c0>
Trace; c0105000 <_stext+0/0>
Trace; c01057ae <arch_kernel_thread+2e/40>
Trace; c0142d50 <kupdate+0/1c0>
Code; c02adbea <lvm_snapshot_remap_block+aa/100>
00000000 <_EIP>:
Code; c02adbea <lvm_snapshot_remap_block+aa/100> <=====
0: 89 42 04 mov %eax,0x4(%edx) <=====
Code; c02adbed <lvm_snapshot_remap_block+ad/100>
3: 8b 03 mov (%ebx),%eax
Code; c02adbef <lvm_snapshot_remap_block+af/100>
5: 89 48 04 mov %ecx,0x4(%eax)
Code; c02adbf2 <lvm_snapshot_remap_block+b2/100>
8: 89 01 mov %eax,(%ecx)
Code; c02adbf4 <lvm_snapshot_remap_block+b4/100>
a: 89 59 04 mov %ebx,0x4(%ecx)
Code; c02adbf7 <lvm_snapshot_remap_block+b7/100>
d: 89 0b mov %ecx,(%ebx)
Code; c02adbf9 <lvm_snapshot_remap_block+b9/100>
f: 89 ca mov %ecx,%edx
Code; c02adbfb <lvm_snapshot_remap_block+bb/100>
11: 90 nop
Code; c02adbfc <lvm_snapshot_remap_block+bc/100>
12: 8d 74 00 00 lea 0x0(%eax,%eax,1),%esi
1 error issued. Results may not be reliable.
Signature · 3 lines
Senior Systems Administrator, NiuTech LLC. AIM: infiniteparticle Cellular: (561) 843-1552
Quoted 1 line · In article <[email protected]> you wrote:
Oops happened after several days of normal operation diring snapshot.
Was the snapshot volumne full? I once had oopses in that situation (with XFS).
Greetings
Bernd
Quoted 2 lines · Bernd Eckenfels
Was the snapshot volumne full? I once had oopses in that situation (with XFS).
Which version of XFS and when? The XFS block allocator uses more stack in low-memory conditions and would over-flow 4K stacks previously but Nathan made some changes which should make it better.
--cw
Quoted 3 lines · Chris Wedgwood
Which version of XFS and when? The XFS block allocator uses more stack in low-memory conditions and would over-flow 4K stacks previously but Nathan made some changes which should make it better.
It was some 2.4 version, but the stacktrace was not related to XFS I think. It was just that reproducible one got panic or oops (not sure) if the snapshot volumne was full. Hevent tried that with 2.6 yet, will do.
Greetings
Bernd
Signature · 4 lines
(OO) -- Bernd_Eckenfels@Mörscher_Strasse_8.76185Karlsruhe.de --
( .. ) ecki@{inka.de,linux.de,debian.org} http://www.eckes.org/
o--o 1024D/E383CD7E eckes@IRCNet v:+497211603874 f:+497211606754
(O____O) When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl!Quoted 3 lines · In article <[email protected]> you wrote:
It was some 2.4 version, but the stacktrace was not related to XFS I think. It was just that reproducible one got panic or oops (not sure) if the snapshot volumne was full. Hevent tried that with 2.6 yet, will do.
Ok, I just retested with 2.6.8.1 and lvm2 on 2 sd disks, I no longer get oops when the snapshot fills up. (However I cant control a policy what should happen on snapshot fillup. Currently it looks like dm-snap is always invalidating the snapshot LV. Other option would be to block IO (on the original drive) or return ENOSPC. I can think of situations where this is desired.
My inital problems howwever have been with lvm1 meta data volumnes and 2.4, cant test those anymore.
Greetings
Bernd