Kairui Song <kasong(a)redhat.com> writes:
What I'm trying to do is reduce the initramfs size used for
kdump.
Kdump loads a crash kernel and kdump initramfs image in a prereseved
memory region, which get booted when current kernel crashed and
perform crash dump. The prereserved memory is limited, so initramfs
shouldn't go too big.
Kdump in Fedora use Dracut to create bootable initramfs, just hook the
final step to do kdump things instead of switch root. And to reduce
the size only the binaries and drivers required to boot and perform
kdump on current machine is installed. So long it have been working
very well.
But problem is Dracut works by reusing binaries and libraries from the
currently running system, and many userspace binaries and libraries is
keep growing and using more space. So the initramfs is also growing.
/root/image/bin/bash
4.8M .
/root/image/bin/sh
4.8M .
So it's not a direct comparison, but:
$ du -sh /bin/bash /bin/dash
1.2M /bin/bash
132K /bin/dash
This suggests to me that 1-3 MB could be reduced by using dash as the
shell. (dash's library dependencies are also smaller since it drops
requirements on libtinfo (200K) and libdl (36K); whether this matters I
don't know.)
Thanks,
--Robbie