On 27/06/2019 1:06 am, Denice Deatrich wrote:
On Wed, 26 Jun 2019, Bill Maidment wrote:
Hi friends
I have run into a problem in SL7.6 copying a large KVM guest lvm
snapshot
file using cp --sparse=always
I get flooded with the following message:
XFS: cp(12985) possible memory allocation deadlock size 131088 in
kmem_realloc (mode:0x250)
The copy ends eventually, but it takes much longer than I expected.
Has anyone else come across this? Googling doesn't throw much light on
this.
Did you come across this article in your searches:
https://urldefense.proofpoint.com/v2/url?u=https-3A__blog.codecentric.de_en_2017_04_xfs-2Dpossible-2Dmemory-2Dallocation-2Ddeadlock-2Dkmem-5Falloc_&d=DwICAg&c=gRgGjJ3BkIsb5y6s49QqsA&r=gd8BzeSQcySVxr0gDWSEbN-P-pgDXkdyCtaMqdCgPPdW1cyL5RIpaIYrCn8C5x2A&m=4GjGRmmnQ9-vd6f8scya52mViTCGS_ZqoGYkx8Kolag&s=eD7uFM_WBarNpN9bJqTk3mUuyJRlCWrpHAFr_t2CoAo&e=
However their deadlock is in kmem_alloc instead, and there is no
mention of LVM. It's a nice analysis - it might shed some light on
the problem.
cheers, etc.
Hi Denice
Thank you very much. This explains a lot. This guest server has never
been reorganised in recent years. A defrag is definitely in order.
--
Cheers
Bill
