Re: [Crash-utility] Reasons why kdump isn't activated
----- "Laurence A. Oberman" <online(a)photonlinux.com> wrote:
Hi Dave
I use crash all the time on SLES dumps. I still have problems with the
SLAB stuff, even with 5.0.
"crash: unable to initialize kmem slab cache subsystem"
Is there a fix for this or am I missing something in creating the
debug vmlinux kernel
crash 5.0.0
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WARNING: could not find MAGIC_START!
please wait... (gathering kmem slab cache data)\
crash: seek error: kernel virtual address: 1082fffea00 type: "kmem_cache
buffer" ---->
crash: unable to initialize kmem slab cache subsystem
SYSTEM MAP: map.0
DEBUG KERNEL: vmlinux (2.6.5-7.244-smp)
DUMPFILE: dump.0
CPUS: 4
DATE: Sat Feb 6 12:43:37 2010
UPTIME: 213503982289 days, 20:38:24
LOAD AVERAGE: 260.75, 259.77, 258.95
TASKS: 1167
NODENAME: linuscs73
RELEASE: 2.6.5-7.252-smp
VERSION: #2 SMP Mon Jun 22 13:11:57 PDT 2009
MACHINE: x86_64 (2666 Mhz)
MEMORY: 32.7 GB
PANIC: "manual"
PID: 8741
COMMAND: "lkcd_config"
TASK: 107ed5d6b40 [THREAD_INFO: 1024f3ac000]
CPU: 2
STATE: TASK_RUNNING (PANIC)
Thanks
Laurence
The "seek error" indicates that the kmem slab page associated with
virtual address 1082fffea00, which is unity-mapped to physical
address 82fffea00, could not be found in the dump.0 file.
If we presume that it is a "correct" address, physical address
82fffea00 is *very* close to the end of physical memory on that
system, which shows "32.7 GB". If you enter:
crash> kmem -p | tail
and wait a while because of the size of the dump, it will eventually
dump the end of the system's mem_map array of physical pages, where
the second column in the list contains the physical address.
I only have one SLES9 (2.6.5-7.315-smp) dumpfile example, which is
a 16GB dumpfile, and the output looks like this:
crash> kmem -p | tail
10407efdd98 407ff5000 0 0 0 d000080
10407efddd0 407ff6000 0 0 0 d000080
10407efde08 407ff7000 0 0 0 d000080
10407efde40 407ff8000 0 0 0 d000080
10407efde78 407ff9000 0 0 0 d000080
10407efdeb0 407ffa000 0 0 0 d000080
10407efdee8 407ffb000 0 0 0 d000080
10407efdf20 407ffc000 0 0 0 d000080
10407efdf58 407ffd000 0 0 0 d000080
10407efdf90 407ffe000 0 0 0 d000080
crash>
where 407ffe000 is the last page of physical memory on the system.
If you do the same thing, how does the last physical page compare
to 82fffea00?
Dave
output looks like this