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
