Re: [ovirt-devel] physical disk management for gluster in vdsm

From: "Saggi Mizrahi" <smizrahi(a)redhat.com&gt; To: "Balamurugan Arumugam" <barumuga(a)redhat.com&gt; Cc: devel(a)ovirt.org Sent: Wednesday, September 24, 2014 1:34:46 PM Subject: Re: [ovirt-devel] physical disk management for gluster in vdsm ----- Original Message ----- > From: "Balamurugan Arumugam" <barumuga(a)redhat.com&gt; > To: devel(a)ovirt.org > Sent: Tuesday, September 23, 2014 2:46:59 PM > Subject: [ovirt-devel] physical disk management for gluster in vdsm > > > Hi All, > > Currently gluster management in ovirt is not complete if disks in hosts are > not formatted/mounted. It expects those actions done prior in the host > added to ovirt. We have a requirement to manage physical disks by > > 1. identify and populate physical disks. > 2. identify and manage hardware raids. > 3. create thick and thin logical volumes in unused physical disks. > 4. format and mount logical volumes. > 5. fstab management for new logical volumes. > > To have this feature, I would like to start a discussion here to explore > possible options suitable for vdsm/engine. > > We have done a small PoC with OpenLMI[1] by having verbs in vdsm to achieve > this. Also we explored ovirt-engine directly calling > tog-pegasus/cim-server > to get cim object to avoid two level of hopes ("ovirt-engine calls vdsm <-> > vdsm calls openlmi locally <-> openlmi does the job" than "ovirt-engine > calls vdsm <-> openlmi does the job") which also works. > > I would like to get your feedback about the PoC and suggestions/ideas how > physical disk management can be. I would prefer not depending on something like openlmi. It replicates or goes against ovirt topology. There is no reason for VDSM to call open something that calls something that goes back to the host and runs fdisk.

I would suggest implementing our own wrappers over the regular linux tools or something local like blivet[1] (used by anaconda).

In general I would like to avoid depending on other daemons as much as possible. We are already having a lot of trouble managing libvirtd and superVDSM.