CHAPTER 12

Managing Storage Pools

9 sections · 14 min read · SimpleVM 10.1

This chapter explains how to work with storage pools — the layer that makes prepared host storage available to SimpleVM for virtual machine disks, installation media, and other VM volumes. A storage pool does not create or manage physical storage; it points SimpleVM at a storage location the host has already prepared, so the management interface can place VM files there. The single most useful idea in this chapter is the boundary between the two layers: the host owns the disks, partitions, filesystems, and mount points; the storage pool is only the VM-facing window onto a prepared location. Keeping that boundary clear is what makes storage changes deliberate and reversible.

Cross-reference: For signing in to the management interface, see Section 6.5, Sign In with Administrative Access. For preparing host disks before they become pools, see Chapter 13, Managing Host Storage. For the VM disks that consume pool capacity, see Chapter 9, Managing VM Disks. For selecting installation media when creating a VM, see Chapter 8, Creating and Managing Virtual Machines. For uploading files with the file browser, see Chapter 19, Host Administration Tools.

This chapter at a glance. The sections below follow how storage reaches your virtual machines:

• Understand pools — what a storage pool is, how it relates to host storage, and which pools a new host already provides (Sections 12.1 and 12.2).
• Work with installation media — how ISO storage is organized and how to place an ISO where SimpleVM can use it (Sections 12.3 and 12.4).
• Add and control pools — create a pool on prepared storage, and activate or deactivate a pool safely (Sections 12.5 and 12.6).
• Stay ahead of capacity — read pool capacity, keep pools from filling up, and apply the production practices that keep storage predictable (Sections 12.7 and 12.8).

12.1 Storage Pool Overview

Overview

A storage pool is the VM-facing storage layer in SimpleVM. It is a managed location — most commonly a directory on a prepared, mounted host volume — where the management interface stores VM disk images, installation media, and other VM volumes. Whenever you create a VM disk, upload an ISO, or take an action that consumes space, SimpleVM is working inside a storage pool.

A storage pool does not replace host storage configuration. The host still owns the disks, partitions, filesystems, mount points, permissions, and capacity planning underneath. The pool is only the window that exposes a prepared location to SimpleVM. In practice the order of work matters: prepare the host storage first, then expose it to SimpleVM as a storage pool. Host-level preparation is covered in Chapter 13, Managing Host Storage.

The Storage pools page and each pool Overview tab report the following:

Verification

• The Storage pools page lists at least the pools your host provides.
• Each pool you intend to use shows State active.
• Expanding a pool shows a Target path that matches the host location you expect.

12.2 Default Storage Pools

Overview

A new SimpleVM host arrives ready for common VM workflows: the Storage pools page already lists two active, directory-based pools — one for VM disk images and one for ISO files. Both are persistent and set to start automatically, so they are available every time the host boots.

Both pools report Persistent yes, Autostart yes, Connection System, and State active. The /data, /data/images, and /data/isos layout is the product standard layout, not only a reference-build choice. Both target paths live on the host separate data volume, mounted at /data, which is why VM data does not compete with operating-system storage.

Before you begin

• You are signed in to the SimpleVM management interface with administrative access. See Section 6.5, Sign In with Administrative Access.

Procedure

1. Open Virtual machines from the left-navigation menu.
2. Select Storage pools. The breadcrumb shows Virtual machines > Storage pools.
3. Confirm that the default and isos pools are listed and show State active.
4. Expand a pool and open its Overview tab to read its Target path, Persistent, Autostart, and Type values.

Verification

• default and isos both appear with State active.
• The Target path values are /data/images and /data/isos.
• Both pools show Persistent yes and Autostart yes.

For the post-installation check that confirms these pools before you build production VMs, see Chapter 5, Post-Installation Configuration (Section 5.7, Verify VM Image and ISO Storage Pools).

12.3 ISO Storage

Overview

ISO storage holds operating-system installation media. When you create a VM and install a guest operating system, SimpleVM needs to reach the ISO file so the VM can boot from it. Keeping ISO files in their own pool — isos, at /data/isos on the reference build — separates installation media from running VM disk images and keeps the VM creation workflow easy to follow.

Use ISO storage for files such as Linux distribution installers, Windows Server installation media, recovery images, or vendor bootable tools. Do not store running VM disk images in the ISO pool unless a specific support workflow tells you to.

Before you begin

• You can sign in to the management interface with administrative access. See Section 6.5, Sign In with Administrative Access.
• The isos pool is active and has enough free space for the media you plan to add. See Section 12.7, Monitoring Storage Pool Capacity.

Verification

• After an ISO is placed in the ISO location, it appears as selectable installation media when you create or edit a VM. See Chapter 8, Creating and Managing Virtual Machines.
• If the ISO does not appear, refresh the page, confirm the file is in the ISO pool target path, and confirm the file has a valid.iso extension and readable permissions.

Troubleshooting

If a newly added ISO does not appear during VM creation, confirm the isos pool is active (Section 12.6), confirm the file is in /data/isos rather than another directory, and refresh the pool storage-volume list. For broader storage problems, see Section 25.5, Storage Issues.

12.4 Uploading Installation Media

Overview

Before you can install a guest from an ISO, the ISO file has to be in the ISO storage location so the VM creation workflow can find it. This section places an ISO into the isos pool. The capture available for this guide confirms the pool Storage volumes tab but not an in-page upload control, so the steps cover both the storage-pool page and the file browser as the transfer path.

Before you begin

• You are signed in with administrative access. See Section 6.5, Sign In with Administrative Access.
• The ISO file has already been downloaded from the operating-system vendor or another trusted source.
• The isos pool is active and has enough free space for the file. See Section 12.7, Monitoring Storage Pool Capacity.
• You know the ISO pool target path. On the reference build it is /data/isos.

Procedure

1. Open Virtual machines, then select Storage pools.
2. Expand the isos pool and open its Storage volumes tab.
3. If the page offers an upload or create-volume control, use it to add the ISO, then wait for the transfer to finish.
4. If the storage-pool page does not offer an upload control, use the file browser instead: upload the ISO to the pool target path (/data/isos on the reference build). See Chapter 19, Host Administration Tools (Section 19.3, Uploading Files and ISOs).
5. Wait for the upload or transfer to complete before selecting the ISO for a VM.

Verification

• The ISO appears in the isos pool Storage volumes list, or in /data/isos through the file browser.
• The isos pool remains active, and its used capacity reflects the added file.
• The ISO is available to select as installation media when you create a VM. See Chapter 8, Creating and Managing Virtual Machines.

Revert this change

If you uploaded the wrong ISO, delete the unused file from the ISO location after confirming that no VM definition or in-progress installation still references it. If a VM already points to the ISO, edit that VM first and remove or replace the ISO reference before deleting the file. See Chapter 8, Creating and Managing Virtual Machines, and Chapter 9, Managing VM Disks for the read-only CD/DVD device on a VM.

12.5 Creating Storage Pools

Overview

Create an additional storage pool when you want SimpleVM to use another prepared storage location — for a new data volume, mounted shared storage, or a separate storage tier for specific workloads. Creating a pool only points SimpleVM at a location that is already prepared and mounted; it does not partition, format, or mount a disk for you.

Before you begin

• You are signed in with administrative access. See Section 6.5, Sign In with Administrative Access.
• The storage location exists on the host and is mounted where you expect it. See Chapter 13, Managing Host Storage.
• The location has enough capacity for the VM disks or ISO files you plan to store there.
• The location is intended for virtualization data and is not part of the operating-system-only volume.
• The target path has the ownership, permissions, and SELinux context a storage pool requires.

Procedure

1. Open Virtual machines, then select Storage pools.
2. Select Create storage pool.
3. Enter a clear pool name that identifies its purpose — for example, vm-data, iso-library, fast-ssd, or archive-storage.
4. Select the pool type. For a local mounted directory, choose a directory-based (dir) pool.
5. Enter the target path for the prepared storage location — for example, /data/vm-data.
6. Enable autostart if the pool should activate automatically when the host restarts.
7. Select the confirmation button shown by the dialog — for example, Create.

Verification

• The new pool appears in the Storage pools list with State active.
• The pool Target path matches the prepared storage location.
• The reported size and used capacity match what you expect for that location.
• If the pool is for VM disks, it is available when you create or add VM storage. See Chapter 9, Managing VM Disks (Section 9.2, Adding VM Disks).

Revert this change

If the pool was created incorrectly and no VM disks or ISO files use it, deactivate it (Section 12.6) and remove the pool definition. Removing a pool definition is not the same as deleting the files inside its target path; confirm which the interface action performs before you proceed. Before removing any pool, verify that no VM disk, snapshot, installation media, or backup workflow depends on it; if anything does, move or detach that storage first.

Optional command-line reference

Most pool tasks belong in the management interface. When the interface is not enough — for advanced troubleshooting or recovery — administrators can inspect and manage pools from the web terminal. See Chapter 19, Host Administration Tools, and the storage commands in Chapter 26, Advanced Administration and Command-Line Reference (Section 26.4, Common Storage Commands).

12.6 Activating and Deactivating Storage Pools

Overview

A pool must be active before SimpleVM can use its volumes. Deactivating a pool makes it unavailable to SimpleVM but does not delete the files inside it — the data stays on disk. Deactivation is useful for maintenance, for troubleshooting, or for temporarily preventing new use of a storage location. Activation simply makes a pool volumes available again.

Before you begin

• You have identified the correct pool and know which VMs or ISO files depend on it.
• No running VM depends on storage that will become unavailable, unless this is a planned maintenance window.

Procedure: deactivate a pool

1. Open Virtual machines, then select Storage pools.
2. Locate the pool and confirm no running VM is actively using its files.
3. Select Deactivate for the pool.
4. Confirm the action if the interface prompts you.

Procedure: activate a pool

1. Open Virtual machines, then select Storage pools.
2. Locate the inactive pool.
3. Select the activate control for the pool.
4. Confirm that State changes to active.

Verification

• After deactivation, the pool shows State inactive and is no longer offered for new VM storage.
• After activation, the pool shows State active and its volumes are available again.
• VMs that depend on the pool can reach their storage once the pool is active.

Revert this change

To reverse a deactivation, activate the pool again. To reverse an activation, deactivate the pool again after confirming no running VM depends on it. If a pool will not activate, confirm the target path exists, the underlying storage is mounted, and permissions allow the host to read the location. See Chapter 13, Managing Host Storage, and Section 25.5, Storage Issues.

12.7 Monitoring Storage Pool Capacity

Overview

Pool capacity directly affects VM reliability. When a pool fills up, VMs that write into it can pause, updates can fail, and — depending on the guest and workload — data can be put at risk. The habit that prevents this is simple: check capacity before any action that consumes space, including creating a VM, expanding a disk, uploading an ISO, or taking a snapshot.

Before you begin

• You are signed in with administrative access. See Section 6.5, Sign In with Administrative Access.

Procedure

1. Open Virtual machines, then select Storage pools.
2. Read the Size value for each pool — used against total, for example 259.42 / 3350.11 GiB.
3. Expand a pool and open Storage volumes to see how individual volumes contribute to the total.
4. Compare the free space with the needs of planned VMs, disk expansions, ISO uploads, and snapshots.
5. If a pool is nearing capacity, hold new space-consuming tasks until you add capacity, remove unused media, or move VM storage to another pool.

Capacity review checklist

• VM disks: confirm room for current use and expected growth.
• Snapshots: confirm headroom before snapshot-heavy maintenance or testing. See Chapter 11, VM Snapshots.
• ISO files: remove installation media you no longer need.
• Backups and exports: avoid writing temporary backup files into a pool that holds active VM disks unless that is the intended design. See Chapter 20, Backup and Recovery.
• For host-level monitoring, see Chapter 23, Monitoring Your SimpleVM Host (Section 23.4, Storage Monitoring).

Verification

• Every pool you depend on has enough free space for its planned workload.
• No pool is unexpectedly near full.
• Pools holding active VM disks have headroom for growth and snapshots.

12.8 Storage Pool Best Practices

Overview

Storage pools are simple to operate, but they sit on top of one of the most important parts of the host. Treat pool design as part of production design, not an afterthought. The practices below keep VM storage predictable and reversible.

Troubleshooting storage pools

Use this table for quick triage. For end-to-end storage diagnosis across the host, see Section 25.5, Storage Issues.