Re: INFO: task hung in sync_blockdev

From: Andrey Ryabinin
Date: Thu Feb 08 2018 - 11:23:31 EST




On 02/08/2018 07:18 PM, Jan Kara wrote:

>> By "full kernel crashdump" you mean kdump thing, or something else?
>
> Yes, the kdump thing (for KVM guest you can grab the memory dump also from
> the host in a simplier way and it should be usable with the crash utility
> AFAIK).
>

In QEMU monitor 'dump-guest-memory' command:

(qemu) help dump-guest-memory
dump-guest-memory [-p] [-d] [-z|-l|-s] filename [begin length] -- dump guest memory into file 'filename'.
-p: do paging to get guest's memory mapping.
-d: return immediately (do not wait for completion).
-z: dump in kdump-compressed format, with zlib compression.
-l: dump in kdump-compressed format, with lzo compression.
-s: dump in kdump-compressed format, with snappy compression.
begin: the starting physical address.
length: the memory size, in bytes