Before updating your OS, deploying a new release, or making any significant configuration change on a VPS, the first thing you should do is create a Snapshot. But how exactly is a snapshot different from a backup — and when should you use one versus the other? This article explains it clearly.
What is a Snapshot?
A Snapshot is a point-in-time image of your entire VPS disk — including the OS, software, configuration files, and all data at the moment it was taken. Think of it as a "saved state" you can instantly roll back to if something goes wrong.
Snapshots work at the block storage level using a Copy-on-Write (CoW) mechanism: only the changed blocks are recorded, which makes creation very fast and initially storage-efficient compared to a full copy.
What is a Backup?
A Backup is a copy of your data transferred to a separate storage location — off-site or remote — that is independent of your production server. Backups are typically scheduled (nightly, weekly) and retain multiple historical versions, giving you a long-term safety net.
Snapshot vs Backup: Side-by-Side Comparison
| Feature | Snapshot | Backup |
|---|---|---|
| Primary Purpose | Emergency rollback, short-term | Long-term data protection |
| Storage Location | Same storage as the VPS | Off-site / Remote storage |
| Creation Speed | Very fast (seconds to minutes) | Slower (depends on data size) |
| Restore Speed | Fast | Slower — data must be transferred |
| Survives Hardware Failure | No (same physical storage) | Yes (separate storage) |
| Retention Period | Short (delete after use) | Long (months of history) |
| Cost | Sometimes included by provider | May incur additional charges |
Snapshot vs Backup: An In-Depth Comparison
Many people assume a snapshot and a backup are the same thing, but they operate at different levels and solve different problems. The table below compares the five dimensions you should understand before designing a data-protection strategy: speed, storage, point-in-time recovery, disaster recovery, and retention.
| Dimension | Snapshot | Backup |
|---|---|---|
| Speed (create / restore) | Very fast — created in seconds to minutes, restored instantly on the same storage | Slower — data must be read, written, and transferred across the network |
| Storage usage | Efficient at first (Copy-on-Write stores only changed blocks) | Uses full space proportional to data size (especially full backups) |
| Point-in-time recovery | Possible, but usually only a few short-lived restore points | Retains many historical versions across days, weeks, or months |
| Disaster recovery | No protection — lives on the same storage as the VPS; lost if the hardware or DC fails | Protected — stored off-site on separate storage or in a different region |
| Retention | Short — should be deleted after use to avoid consuming storage | Long — kept per policy, e.g. 30–90 days or longer |
In short, snapshots excel at speed and ad-hoc rollback, while backups excel at durability and long-term disaster recovery. They are not competitors — they complement each other.
When to Use a Snapshot (Before Updating / Migrating)
The best time to create a snapshot is right before a risky change. Because snapshots are fast to create and instant to restore, they make an excellent "save point" before doing something that could break your system. Moments where you should always take a snapshot:
- Before an OS or kernel update — updates that touch the boot loader or drivers can leave a server unable to boot; a snapshot lets you roll back in a minute
- Before migrating, moving servers, or upgrading a plan — capture the current state first, so you can return to a known-good baseline if the migration goes wrong
- Before deploying a major release that involves database schema changes or large dependency upgrades
- Before editing config that could lock you out — SSH, firewall rules, or network interfaces
A simple rule of thumb: if what you are about to do "would be hard to undo or slow to recover from," take a snapshot first. It costs a few seconds but can save you hours in an emergency.
Why a Snapshot Is Not a Backup
This is the most dangerous misconception: people take a snapshot and assume they are "safe and don't need a backup." That is plainly wrong, for three main reasons:
- It lives on the same storage as your VPS — most snapshots are stored on the same storage pool as the VPS disk. If that storage fails, the RAID array dies, or the data centre has an incident, the snapshot is lost along with the original data — leaving nothing to recover from.
- It is not designed for long-term retention — snapshots kept for a long time consume increasingly more storage (they accumulate divergent blocks) and can hurt disk performance, so they should remain temporary.
- It does not protect against slow-to-detect logical errors — if data is corrupted silently (ransomware, an accidental deletion) and you only notice days later, short-lived snapshots are likely already gone, whereas a backup with a long history can still recover it.
⚠️ Remember: a snapshot is an "emergency Undo button" that lives inside the same house. If the house burns down, the Undo button burns with it — a backup is the copy you keep outside the house.
Best Practice: Snapshot + Offsite Backup Together
The correct approach is not to pick one — it is to use both, each for its strengths:
- Use snapshots as short-term save points before changes (updates, deploys, migrations) — fast to create, fast to roll back, then delete once you are confident the new state is stable
- Use offsite backups as your long-term safety net — schedule daily or weekly backups that send data to storage separate from the VPS, such as S3-compatible object storage or a remote server in a different region
- Test your restores periodically — a backup you cannot restore is no backup at all; perform a real recovery at least once a quarter
The 3-2-1 rule to follow: keep 3 copies of important data, on 2 different media or systems, with at least 1 copy off-site. A snapshot counts as only part of the "2 media" — you still need an offsite backup to complete the set.
When Should You Take a Snapshot?
- Before an OS update — e.g.,
apt upgradeor a kernel update that could prevent the system from booting - Before deploying a major release — especially when database schema migrations are involved
- Before changing critical config — Nginx, MySQL, firewall rules
- Before installing new software — which might conflict with existing packages
- Before migrating or upgrading — moving to a new server or a higher plan
⚠️ A snapshot is not a permanent backup: If the underlying storage fails or the data centre has a critical incident, any snapshots on that same storage are also lost. You need both snapshots (for quick rollback) and backups (for long-term safety).
How to Create a Snapshot (Provider Level)
Snapshots are taken from your VPS provider's control panel, not from inside the server itself. The general process:
- Log in to your VPS provider's dashboard
- Navigate to the VPS you want to snapshot
- Click on Snapshots or Images
- Click Take Snapshot or Create Snapshot
- Give it a descriptive name — e.g.,
before-laravel-v2-deploy - Wait for the process to complete (a few minutes to half an hour depending on disk size)
How to Restore from a Snapshot
- Power off the VPS (some providers support live restore)
- Go to Snapshots → select the snapshot you want
- Click Restore or Rebuild from Snapshot
- Confirm — the system will overwrite the current disk with the snapshot state
Important: Restoring from a snapshot overwrites everything on the current disk. Any data added or changed after the snapshot was taken will be lost. Always double-check before confirming a restore.
File-Level Backup with rsync
For incremental backups that are simple and cost-effective, use rsync to send data to a remote server or an S3-compatible object storage service (e.g., Wasabi, Backblaze B2). This complements snapshots by storing changes off-site on a schedule you control.
A mature backup strategy uses snapshots for instant rollback and scheduled remote backups for historical recovery — never one without the other.
The 3-2-1 Rule: Keep 3 copies of important data, on 2 different media types, with 1 copy stored off-site. A snapshot fulfils only part of this — it is not a complete backup strategy on its own.
Frequently Asked Questions (FAQ)
Can a snapshot replace a backup?
No. Most snapshots live on the same storage as your VPS, so if that storage or the data centre fails, the snapshot is lost with it. Use snapshots for short-term rollback and always keep a separate offsite backup for long-term recovery.
Will restoring from a snapshot delete my current data?
Yes. Restoring overwrites the entire disk back to its state when the snapshot was taken. Any data added or changed afterward is lost, so always check and back up critical files before you restore.
How long should I keep a snapshot?
Snapshots are temporary. Keep one only while you are still unsure the new state is stable; once everything is confirmed working, delete it. Long-lived snapshots consume increasing storage and can degrade disk performance.
Does AsiaGB VPS include snapshot support?
Yes. AsiaGB VPS supports creating snapshots from the control panel, with full root access and high-speed SSD storage, starting from 500 THB/month — ideal for WordPress, e-commerce, Node.js, and business apps.
VPS with Snapshot and Backup Features Built In
AsiaGB VPS includes snapshot support via the control panel, full root access, and high-speed SSD storage — everything you need to stay protected.
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