America, To clarify, crashkernel=480 at 2G or @1G doesn"t work either. Further, for older kernels (2.6.32) it was possible to create crashkernel areas larger than 480M (crashkernel=512M). Starting somewhere around 2.6.36, this stopped working. Are you saying this was an intentional change? tim On Nov 16, 2011 4:47 AM, "Am?rico Wang" <xiyou.wangcong at gmail.com> wrote: > On Wed, Nov 16, 2011 at 6:57 AM, Tim Hartrick <tim at edgecast.com> wrote: > > > > Americo, > > > > I downloaded the source for kexec-tools 1:2.0.2-1ubuntu3 and rebuilt it > > with -DDEBUG and installed. Below are the results using the > > 2.6.38-8-server Ubuntu kernel as base and crashkernel. Note that the > > crashkernel size has been increased to 479M. > > > Thanks for testing! > > > > > While I have the list's attention, I would like to mention another > > problem in this area. The 2.6.38-8-server kernel cannot create a > > crashkernel area greater than 479M in size (e.g. crashkernel=480M). If > > the crashkernel is relocated (e.g. crashkernel=480M at 8G), then the kernel > > will create the area but kexec (1:2.0.1-1ubuntu3) fails while attempting > > to load crashkernel into the reserved area. > > > I am afraid kexec can't load the kernel to memory above 4G. > > > > > This is a fatal problem since the 2.6.38-8-server kernel running as > > crashkernel requires more than 479M of crashkernel area to successfully > > take a dump on our systems. I will be happy to provide additional > > information about this one as well. > > Well, this is not kernel problem, it is a problem of your kdump tool > on Ubuntu, the initrd of the second kernel should do as minimum things > as possible. > > > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > Elf header: p_type = 4, p_offset = 0xdb74000000000000 p_paddr = > 0xdb74000000000000 p_vaddr = 0x0 p_filesz = 0x400 p_memsz = 0x400 > > You have 8 cpus, but it is strange that these PT_NOTE program headers > are all same... > > So, can you show us the output of the following commands on your machine? > > #hexdump -C /sys/kernel/crash_notes > #for i in /sys/devices/system/cpu/cpu*/crash_notes; do hexdump -C $i; done > > Thanks. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.infradead.org/pipermail/kexec/attachments/20111116/8563ab18/attachment.html>
