Testing ZFS with XCP-ng

nraynaud

@borzel good catch, it's another O_DIRECT issue.

nraynaud

@borzel I am struggling to match the error lines in your log with a source code, can you tell me what version of vhd-tool you have installed please ? (yum info vhd-tool)

borzel

@nraynaud

# yum info vhd-tool
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Installed Packages
Name        : vhd-tool
Arch        : x86_64
Version     : 0.20.0
Release     : 4.2.xcp.el7.centos.extras
Size        : 40 M
Repo        : installed
From repo   : xcp-ng-extras
Summary     : Command-line tools for manipulating and
            : streaming .vhd format files
URL         : https://github.com/xapi-project/vhd-tool
License     : LGPL+linking exception
Description : Simple command-line tools for manipulating an
            : streaming .vhd format file.

nraynaud

Thanks,
I have found a suspected O_DIRECT here, the solution won't come quickly.

SeyedGH

Does this issue also have a role if you run glusterfs on top of zfs?
Or is it just directly on zfs.

Because i would want to runs glusterfs on top of zfs on a spearate server, and use glusterfs driver to connect to it.

Do i also have this issue then?

borzel

@nraynaud I just tested with an up-to-date XCP-ng 7.5 host, same failure

# yum info vhd-tool
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Installed Packages
Name        : vhd-tool
Arch        : x86_64
Version     : 0.20.0
Release     : 4.3.xcp.el7.centos
Size        : 40 M
Repo        : installed
From repo   : xcp-ng-updates
Summary     : Command-line tools for manipulating and streaming .vhd format files
URL         : https://github.com/xapi-project/vhd-tool
License     : LGPL+linking exception
Description : Simple command-line tools for manipulating and streaming .vhd format file.

nraynaud

I am till on the issue, the subject is way deeper than expected.

borzel

@nraynaud take your time, no rush

borzel

Just added the setup part to https://github.com/xcp-ng/xcp/wiki/ZFS-on-XCP-ng-7.5-and-later#setup

stormi

Thanks @borzel

dvdhngs

Hello everybody! Newbie here, just 24h of xcp use, I was trying set Raid 10, but xcp only support Raid 1, so I'm trying now to set raidz, like on the document, I'm using 4 disks (500gb each), but I want to do Raid on this 4 disks (sda,sdb,sdc,sdd), so I can't? Need to be 6 disks? 2 raid 1 with xcp, and 4 raidz for other things?

olivierlambert

Hi,

There is 2 different things:

soft RAID 1 support during install, using mdadm (the standard Linux software RAID mechanism)
ZFS support for storage repositories (where you store your VM disks)

Regarding your use case, it depends. You can choose to install XCP-ng system without RAID and use only one disk, and the rest for ZFS SR. Or RAID1 for XCP-ng system, and the left disks for ZFS.

dvdhngs

@olivierlambert
Just to solve a doubt.... there is no way to install xcp-ng on software RAID 10, right?

borzel

@dvdhngs

install onto (mdadm/ZFS) RAID 10: no

to use (mdadm/ZFS) RAID 10 as SR: yes, of course!