On Sat, Feb 12, 2022 at 9:21 AM Glen Jarvis <glen(a)glenjarvis.com> wrote:
> I would like to know why "vdsm-tool config-lvm-filter" makes
> you pull your hair out.
>
> It was designed to help people configure their system
> correctly without pulling their hair out trying to
> understand how lvm filter works, and avoid the many
> wrong ways it can be used.
Honestly, it is just from a lack of understanding of what is happening
when it does break (as it is for us when doing a hypervisor install on a
fresh box). Normally, I can just dig through the stack and figure out what
is happening. There are enough areas where I don't have some foundations
that I'm not able to do so here (yet).
For example, I don't quite understand iSCSI, Multipath, etc enough to know
what is breaking, and why.
I'm accustomed to being able to dig deeper at each level until I can
generally see what is breaking.
This confusion will go away as I get a bit more experience and have a
"map" of what is going on on this level.
FWIW, I started reading the Libvirt book previously mentioned and it's
pretty straight forward. It looks like I just need to get through this
enough to get a good foothold so that I can figure out how to either fix
things when they break or point out properly why something is breaking (so
I can get the appropriate help).
>
> Do you have some specific areas you would like to improve?
>
Actually, yes :) In:
1. Learn libvirt more (in progress)
2. Review source for vdsm-tool to have a better sense what is going on
3. Setup an iSCSI system so that I can make luns, build a system,
play
with storage pools this way
You may find vdsm/contrib/target tool useful:
https://github.com/oVirt/vdsm/blob/master/contrib/target
This tool makes it simple to create or delete a new iSCSI target for
development purposes.
The best way to add iSCSI server for development, is to create a new VM -
virt-manager is the easier way to do this, and install targetcli and copy
vdsm/contrib/target to the vm.
Then to create a new target you can run:
# ./target create mytarget
Creating target
target_name: mytarget
target_iqn: iqn.2003-01.org.alpine.mytarget
target_dir: /target/mytarget
lun_count: 10
lun_size: 100 GiB
cache: False
exists: False
Create target? [N/y]:
You may find the tool source interesting, explaining why we configure
the target in a certain way.
Nir