Thin provision is a mechanism that you can allocate a lvm volume which has
a large virtual size for file systems but actually in a small physical
size. The physical size can be autoextended in use if thin pool reached a
threshold specified in /etc/lvm/lvm.conf.
There are 3 works should be handled when enable lvm2 thinp for kdump:
1) Check if the dump target device or directory is thinp device.
2) Monitor the thin pool and autoextend its size when it reached the threshold
during kdump.
3) If thin pool size-autoextend fails, the user space program will not know due to
buffered IO. So the lvm2 thinp dump target should be mounted with sync flag, making
user space program know immediately if write fails.
According to my testing, the memory consumption procedure for lvm2 thinp is the thin pool
size-autoextend phase. For fedora and rhel9, the default crashkernel value is enough. But
for rhel8, the default crashkernel value 1G-4G:160M is not enough, so it should
be handled particularly.
Please review.
Tao Liu (4):
Add lvm2 thin provision dump target checker
Add lvm2-monitor.service for kdump when lvm2 thinp enabled
lvm.conf should be check modified if lvm2 thinp enabled
Mount the lvm2 thinp target with sync option
dracut-lvm2-monitor.service | 15 +++++++++++++++
dracut-module-setup.sh | 16 ++++++++++++++++
kdump-lib-initramfs.sh | 25 +++++++++++++++++++++++++
kdumpctl | 1 +
kexec-tools.spec | 2 ++
mkdumprd | 5 +++++
6 files changed, 64 insertions(+)
create mode 100644 dracut-lvm2-monitor.service
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2.33.1