[SOLVED] Proxmox confused about SAN Storage Capacity

[Technolust]

We built proxmox on Cisco UCS Blades and NetApp Storage. When you attach SAN LUN over Fibre Channel Proxmox will see the LUN and it's capacity. However, when you try to build a VM or container Proxmox shows 0 available storage to build onto. The issue is, Proxmox adds a global filter to the /etc/lvm/lvm.conf file and when you create a LUN and attach it to Proxmox it then creates a preferred_names filter under a different block.

The fix is to edit the /etc/lvm/lvm.conf file under the devices { } section at the end.

This is the original:

devices {
 global_filter=["r|/dev/zd.*|","r|/dev/rbd.*|"]
}
devices {
 preferred_names = [ "^/dev/mapper/", "^/dev/sd" ]
 filter = [ "a|/dev/mapper/.*|", "r|/dev/sd.*|" ]
}

This is what it needs to look like:

devices {
    # added by pve-manager to avoid scanning ZFS zvols and Ceph rbds
    global_filter = [ "r|/dev/zd.*|", "r|/dev/rbd.*|" ]

    preferred_names = [ "^/dev/mapper/", "^/dev/sd" ]
    filter = [ "a|/dev/mapper/.*|", "r|/dev/sd.*|" ]
}

Just thought I would post this for anyone looking for help and to maybe see if proxmox devs can fix this in an update.

 

[bbgeek17]

Hi @Technolust , welcome to the forum.

Thank you for sharing this interesting observation. However, the default PVE installation does not come with lvm.conf containing two "devices{}" stanzas.
Something happened to your file, most likely human intervention.

LVM does not merge duplicate config entries - the last one wins. So the behavior you saw is expected for a misconfigured system.

Cheers

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[Technolust]

Hi @Technolust , welcome to the forum.

Thank you for sharing this interesting observation. However, the default PVE installation does not come with lvm.conf containing two "devices{}" stanzas.
Something happened to your file, most likely human intervention.

LVM does not merge duplicate config entries - the last one wins. So the behavior you saw is expected for a misconfigured system.

Cheers

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

Thank bbgeek17, interesting if it doesn’t have two stanzas/entries by default. We initially didn’t change the file until ChatGPT noted to change it. The only thing I could think of is we built the 10TB LVM and then removed it after it didn’t let us build a VM the first time. Then after rebuilding the storage and recreating the LVM again ChatGPT said to make the change and once we did it let us build a VM on the 10TB LUN.

Wish I could figure out what created it but I couldn’t and just thought I would at least post the fix just in the happenstance someone else has the issue.

Cheers!

 

[bbgeek17]

Then after rebuilding the storage and recreating the LVM again ChatGPT said to make the change and once we did it let us build a VM on the 10TB LUN.

Most likely the erroneous entry was made at this time. It worked partially based on the last entered configuration until you needed the first part as well.

Given that you found a solution to your issue, you should mark this thread as Solved by editing the first post and selecting the appropriate prefix from the subject dropdown. This will help in keeping the forum tidy.

Cheers

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox