Every new Proxmox user meets two storages named local and local-lvm and wonders why there are two and which one holds what. The answer is simple once somebody says it plainly: one is a folder for files, the other is a pool for virtual disks. Here is the map, plus the thin-provisioning warning that comes with it.
Upload an ISO and it lands in one place; create a VM and its disk lives in another; run a backup and you must choose a third decision. Proxmox's storage model is genuinely logical — but nobody explains it during the install. This page is the explanation: what local and local-lvm each are, what belongs in them, and the one trap built into the design.
A default Proxmox install splits your disk into two storage areas with two different jobs, and the names confuse everyone on day one. local is an ordinary folder on the system disk. It holds the files you can see and copy: ISO images, container templates, and backup files. local-lvm is an LVM-thin storage pool, and it holds the thing you cannot simply copy: the virtual disks of your VMs and containers. When you create a VM and Proxmox asks where its disk goes, local-lvm is the default answer — and the right one.
LVM-thin gives VM disks three abilities a plain folder cannot match as neatly: snapshots (freeze a VM's disk in a moment and roll back to it), thin provisioning (a 100 GB virtual disk only consumes the space actually written — a fresh install might use 8 GB), and clean, fast cloning. The thin part carries one honest warning: you may promise more disk than you physically have, because five 100 GB disks fit 'on paper' into a 300 GB pool. The day all five actually fill up, the pool is full and VMs start failing with disk errors. Thin provisioning is a loan — keep an eye on the pool's real usage in the summary screen and it will never ambush you.
If you later add a second SSD or hard disk, you register it as additional storage and can move VM disks onto it live-ish from the VM's Hardware tab (Disk Action → Move Storage). The two default areas stay as they are; your new space simply joins the map.
Under the installer's disk Options you can change how much of the disk the Proxmox system itself reserves (the hdsize and related settings). Beginners sometimes shrink the system area to give VMs 'more room' without understanding that local and local-lvm are carved from this layout — starve the system side and you will be the person whose ISO uploads and backups fail with a full disk while half the drive sits unused in the other pool. The default split is well judged. Unless you can explain exactly why you are changing it, leave it alone and add a second disk later when you genuinely need space.
See the full Proxmox installation and first VM creation, live and step by step.
▶️ Watch Full VideoTechnically possible with file-based disk images, but you give up the clean snapshot and thin-pool behaviour local-lvm was built for, and you mix guests into the system area. The default exists for good reasons — keep VM disks on local-lvm.
Almost always backups or too many ISO images piling up in local. The two areas cannot borrow from each other. Delete unneeded ISOs, prune old backups, or add a second disk and move the backup target there.
In the web interface, select the node, open Disks to initialise the new drive, then go to Datacenter → Storage → Add and create a Directory or LVM storage on it. Afterwards you can move VM disks onto it from each VM's Hardware tab.