Re: Issue with fstrim and Nova hw_disk_discard=unmap

[Fulvio Galeazzi <fulvio.galeazzi@xxxxxxx>]

Hallo!

> Discards appear like they are being sent to the device.  How big of a
> temporary file did you create and then delete? Did you sync the file
> to disk before deleting it? What version of qemu-kvm are you running?

I made several test with commands like (issuing sync after each operation):

dd if=/dev/zero of=/tmp/fileTest bs=1M count=200 oflag=direct

What I see is that if I repeat the command with count<=200 the size does 
not increase.

Let's try now with count>200:

NAME                                        PROVISIONED  USED
volume-80838a69-e544-47eb-b981-a4786be89736      15360M 2284M

dd if=/dev/zero of=/tmp/fileTest bs=1M count=750 oflag=direct
dd if=/dev/zero of=/tmp/fileTest2 bs=1M count=750 oflag=direct
sync

NAME                                        PROVISIONED  USED
volume-80838a69-e544-47eb-b981-a4786be89736      15360M 2528M

rm /tmp/fileTest*
sync
sudo fstrim -v /
/: 14.1 GiB (15145271296 bytes) trimmed

NAME                                        PROVISIONED  USED
volume-80838a69-e544-47eb-b981-a4786be89736      15360M 2528M



As for qemu-kvm, the guest OS is CentOS7, with:

[centos@testcentos-deco3 tmp]$ rpm -qa | grep qemu
qemu-guest-agent-2.8.0-2.el7.x86_64

while the host is Ubuntu 16 with:

root@pa1-r2-s10:/home/ubuntu# dpkg -l | grep qemu
ii  qemu-block-extra:amd64               1:2.8+dfsg-3ubuntu2.9~cloud1 
           amd64        extra block backend modules for qemu-system and 
qemu-utils
ii  qemu-kvm                             1:2.8+dfsg-3ubuntu2.9~cloud1 
           amd64        QEMU Full virtualization
ii  qemu-system-common                   1:2.8+dfsg-3ubuntu2.9~cloud1 
           amd64        QEMU full system emulation binaries (common files)
ii  qemu-system-x86                      1:2.8+dfsg-3ubuntu2.9~cloud1 
           amd64        QEMU full system emulation binaries (x86)
ii  qemu-utils                           1:2.8+dfsg-3ubuntu2.9~cloud1 
           amd64        QEMU utilities


  Thanks!

			Fulvio

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature

_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com