On 2016/04/01 at 11:51, Pratyush Anand wrote:
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.
Glad to hear that. Very cool~
Regards,
Xunlei
~Pratyush