Hello Michael, On Wed, 11 Apr 2012 10:04:03 +0200 Michael Holzheu <holzheu at linux.vnet.ibm.com> wrote: > > bitmap file is main cause of memory consuming if 2nd kernel uses initramfs > > only. There are other parts where the size of allocated memory varies based > > on 1-st kernel memory size, but they don't have big influence. > > Thanks for the explanation. > > I ask because I want to exactly calculate the required size for the > crashkernel parameter. On s390 the kdump kernel memory consumption is > fix and not dependent on the 1st kernel memory size. So based on your > explanation I, will use: > > crashkernel=<base size> + <variable size> > > where > > <variable size> = <pages of 1st kernel> * (2 + x) / 8 > > where "x" is the variable makedumpfile memory allocation that is on top > of the bitmap allocation. What would be a good value for "x"? I'm sorry that I don't have the exact number, but even the second biggest memory allocation would require under 1/100 of the bitmap size, so, I think 0.01 is usually enough for "x". Thanks Atsushi Kumagai
