Proxmox 4.2 installation bug

[CTCcloud]

This has happened a number of times now. I've used the Proxmox 4.2 ISO to do a fresh server install. After finished I find that /dev/mapper/pve-data has not been formatted nor is in fstab to be mounted. Local storage ends up on the root filesystem which typical is only around 97GB big which doesn't leave room for KVM guests. Is there a work around? Is this a bug? What's the best way to handle this? Use Proxmox 4.1 install ISO instead? Will this be fixed in Proxmox 4.3 install?

Thanks

 

[fabian]

the default "big" storage is now an LVM-Thin pool, which cannot be mounted directly. it is configured as "local-lvm" storage.

 

[CTCcloud]

What do you mean by "cannot be mounted directly"? What then becomes the default workable local storage?

Also, what exactly is "LVM-Thin" storage? What's it useful for?

 

[LnxBil]

What do you mean by "cannot be mounted directly"?

It's not a regular volume, so there is no filesystem, ego it cannot be mounted.

What then becomes the default workable local storage?

Thin-LVM is the default storage, so RAW on LVM, but in a thin provisioned manner.

Also, what exactly is "LVM-Thin" storage? What's it useful for?

It's still LVM, so it is as already described a RAW storage medium. Thin means here that only the actual written blocks are stored and not everything is preallocated as it was before. The "thick" LVM allocates 100 GB space if you want a volume of 100 GB, with thin provisioning, you'll have only a fraction of the allocated space, which will be allocated if the virtual disk is filled. This is more intelligent and allows over-provisioning of a storage system.

For more information, please refer to https://pve.proxmox.com/wiki/LVM2#LVM-Thin

If you think that it's not what you want, you can either

• Revert to the old behavior (=> https://pve.proxmox.com/wiki/Instal....2Fvar.2Flib.2Fvz_.28Proxmox_4.2_and_later.29)
• create /var/lib/vz as a volume and use it as before (=> https://pve.proxmox.com/wiki/LVM2#Create_a_extra_LV_for_.2Fvar.2Flib.2Fvz)

 

[CTCcloud]

Thanks for the explanation. I had already looked up LVM-Thin provisioning before you replied so was at least aware of that. Yes, I know there isn't a filesystem by default ... I guess the biggest problem is that there isn't anything in the Proxmox 4.2 announcement that says LVM-Thin becomes the default VM storage that I could see. We have a large number of Proxmox installations and various clusters. When installing a new server and putting it into an existing cluster this default simply creates more work for administrators. It's only useful to someone installing for the first time. We've been using Proxmox since version 2.x (only reason we didn't use it before was because we were waiting for certain features and greater stability) so our install base makes this sort of change of defaults difficult to deal with. Such a wholesale move away from the default storage should have been pushed to version 5.0, not quietly shoved into a minor release causing headache for current users and their installed bases.

I don't mean to rant here, just irritated. We've always considered Proxmox a great platform and still do but this kind of "monkey wrench" in the works doesn't feal good for IT guys that are in the middle of dealing with actual real life customer emergencies. Enterprise ready means stability, not just in the software's day to day performance but also in it's features so that admins don't get new features that derail their normal administration. New features like this need to be planned in for migration not simply thrown in at the last minute and on a whim.

I saw that LVM Thin provisioning was added in in 4.1 as a "technology preview" and then in 4.2 it simply says LVM-Thin support. Great, nice to have new features and maybe I'll use that for a brand new install somewhere especially now that I know what exactly it accomplishes but it's much better to know that the default was changed loud and clear and why it was changed and why it was added in the middle of a release version instead of new major release.

Anyway...to the Proxmox guys ... the platform is a nice platform. Keep up the good work.

 

[LnxBil]

I agree. We'll see it they change it back in the next release. There were lots of posts complaining about it.