On a server with multiple clients or websites, it’s wise to set resource limits. This prevents one busy site from hogging all the CPU or memory, which would slow down other sites. In Plesk, you manage this through resource packages and limits per subscription, ensuring each client gets a fair and predictable share of server capacity.
Why set resource limits
Without limits, a single website with a traffic spike or a poorly optimized script can use so much CPU and memory that other websites on the same server respond more slowly or even become temporarily unreachable. This is called “noisy neighbor” behavior. By setting limits per client or subscription, you guarantee stability for all users on the server and avoid having to intervene manually every time there’s overload.
Resource limits are also useful for offering different service levels. For example, you could combine a cheaper package with lower limits with a premium package that gets more CPU and memory allocated.
Which resources can you limit
When creating or editing a subscription in Plesk, you can restrict several resources:
- CPU: the maximum percentage of processor capacity a client is allowed to use.
- Memory (RAM): the amount of working memory available to that client’s processes.
- Disk space: the total storage for websites, email, and databases.
- Traffic (bandwidth): the maximum data traffic per month.
- Number of websites, databases, and mailboxes: so clients stay within their package limits.
- Concurrent processes: for example, the number of PHP processes or connections.
Not every limit is relevant for every client. For a simple brochure website, disk space and traffic are often more important than CPU, while a webshop benefits more from sufficient memory and processes.
Setting limits in Plesk
Plesk offers a clear interface for setting limits, both for individual subscriptions and for service plans applied to multiple clients.
Open service plans
In Plesk, go to Service Plans and create a new plan or edit an existing one.
Set resource limits
On the Resources tab, enter the maximum values for disk space, traffic, number of domains, databases, and mailboxes.
Configure CPU and memory limits
Using the resource control settings (on servers with this module), set the maximum CPU percentage and memory usage per subscription, so processes are automatically restricted.
Link the plan to clients
Assign the service plan to new or existing subscriptions, so the limits are automatically applied.
Test the limits
After setup, check whether a test website keeps working within the set boundaries and whether exceeding them is handled gracefully, for example with a warning instead of a crash.
Monitoring and adjusting limits
Setting limits is not a one-time action. Websites grow, visitor numbers change, and clients expand their services. Therefore, regularly check the resource usage per subscription in Plesk, for example via the statistics page per client.
If a client consistently hits their limit, that’s often a sign they should upgrade to a higher package rather than simply raising the limit. This keeps the service level logically tied to the purchased package and keeps the server stable for everyone. If you’re considering switching to a provider that manages this for you, read more about switching to Tandata or check out the options for web hosting with fixed prices and NVMe storage.
Frequently Asked Questions
What happens if a client exceeds their limit?
Depending on the setting, the process gets lower priority, traffic is slowed down, or the client receives a notification. The server generally remains stable for other users.
Can I deviate from the default plan for individual clients?
Yes, you can create a custom subscription or manually adjust the resource limits per client in Plesk after assigning a plan.
Does a limit also apply to email?
Yes, you can restrict the number of mailboxes and the storage per mailbox. For reliable business email with a good configuration, check out business email.
Do resource limits affect website loading speed?
Only if the limit is actually reached. Under normal usage, a client won’t notice the set boundaries at all.
Where can I find more explanation about server management?
Check out the knowledge base for more articles on server management and Plesk configuration.
Conclusion
By setting resource limits per client in Plesk, you prevent one website from overloading the entire server and ensure a stable, predictable environment for all users. Start with service plans, set realistic limits, and monitor usage regularly to adjust where needed.