Hi Xunlei,
Thanks for your review.
On 01/04/2016:09:51:50 AM, Xunlei Pang wrote:
On 2016/03/30 at 15:45, Pratyush Anand wrote:
> kdump also passes persistent device mapping as --mount or --device argument
> of dracut. However this persistent id (UUID) is changed if dump target is
> re-formated.
> kdumpctl must have a mechanism to recognise this modification, so that its
> service restart is able to rebuild initramfs.
>
> Testing:
> * When raw target is raid device, dracut argument is passed as --device
> '/dev/mapper/xxxxx', and in this case it does not force rebuild after
> reformatting. vmcore save was also fine.
> * When raw target is an ide device, dracut argument is passed as --device
> '/dev/disk/by-uuid/xxxxx', and in this case it does force rebuild after
> reformatting.
> * Similar test was also performed as ext4, xfs and btrfs file system target.
>
> One of the test case's detailed illustration:
> a) Attach an IDE device, lets say it is /dev/sdb1
> b) Format it as ext4
> # mkfs.ext4 /dev/sdb1
> # blkid /dev/sdb1
> /dev/sdb1: UUID="21c7baff-e35d-49c7-aa08-0fba4513f5bf"
TYPE="ext4"
> c) Mount it into /mnt and create a var/crash directory in it.
> # mount /dev/sdb1 /mnt;mkdir /mnt/var;mkdir /mnt/var/crash
> d) Add following line in /etc/kdump.conf
> ext4 /dev/sdb1
> e) Restart kdumpctl
> # kdumpctl restart
Should we make this more intelligent? i.e. open a daemon, if detecting such
modification(poll or better utilize some kernel notification mechanism), then
restart dump automatically without user's manual intervention.
Yes, this is on agenda and will be done after active watchdog detection patches
are also upstreamed.
~Pratyush