- 1. RAM – Memory allocated to web applications
- 2. CPU – Processing power (percentage or core allocated)
- 3. EP – Entry Processes (simultaneous entry processes)
- 4. I/O – Disk read/write speed
- 5. IOPS – Number of I/O operations per second
- 6. NPROC – Number of simultaneous processes
- 7. Inodes – Total number of files and directories
- 8. Emails per hour – anti-spam limits
- Conclusion
When choosing a web hosting plan, especially in a shared hosting environment, it’s essential to understand that beyond space and traffic, there are technical limits imposed on each account to ensure overall server stability. These limits are managed by CloudLinux, a technology that isolates each account in its own environment, similar to a mini-container (LVE – Lightweight Virtual Environment).
These limitations affect your site’s performance, stability, and scalability. Here are the details:
1. RAM – Memory allocated to web applications
- What it is: RAM enables running scripts, executing PHP code, SQL queries, etc.
- When exceeded: PHP processes may be abruptly terminated, and the site may return errors like 500 Internal Server Error.
- Example: WordPress with WooCommerce requires at least 2 GB RAM for decent performance.
2. CPU – Processing power (percentage or core allocated)
- What it is: Limits how much of the server’s processor capacity your account can use.
- Exceeding the limit: leads to site slowdown, timeouts, and temporary suspension of processes.
- Note: 100% CPU means 1 processor core. Standard packages offer between 100% and 500% (1-5 cores).
3. EP – Entry Processes (simultaneous entry processes)
- What it is: Number of simultaneous requests to PHP files (not total visitors).
- Example: If a script takes 2 seconds to execute and you have 20 EP, your site can process only 20 simultaneous requests.
- Exceeding: results in blocking new requests and slow loading or errors.
4. I/O – Disk read/write speed
- What it is: Measures how fast files can be read or written in the hosting space.
- Exceeding: causes delays in loading the site or control panel.
- Common values: between 1 MB/s and 5 MB/s on shared packages. SSD server helps but you are still limited by CloudLinux settings.
5. IOPS – Number of I/O operations per second
- What it is: Unlike I/O (measured in MB/s), IOPS counts how many operations (read/write) can be performed per second, regardless of file size.
- Exceeding the limit: delays script execution or database interactions.
- Example: A site accessing many small files may reach IOPS limits faster than I/O (MB/s) limits.
6. NPROC – Number of simultaneous processes
- What it is: Determines how many processes can run simultaneously in your account (including PHP processes, cron jobs, SSH commands).
- Exceeding: blocks execution of new processes, which can lead to errors or application failure.
- Note: Essential for sites running many cron jobs, automated plugins, or asynchronous tasks.
7. Inodes – Total number of files and directories
- What it is: An inode represents a file or directory. The limit applies to their total number, regardless of size.
- Exceeding: completely stops file uploads and creation of new directories. Automatic backups may fail.
- Example: 250,000 inodes = 250,000 files/directories (e.g., a cache folder can create tens of thousands of files).
8. Emails per hour – anti-spam limits
- What it is: Maximum number of emails you can send per hour.
- Common values: between 50 and 300 emails/hour per account.
- Exceeding: leads to temporary blocking of message sending.
- Solutions: For large volumes, use dedicated services like mailMachine.ro, Mailchimp, MailerLite, etc.
Conclusion
CloudLinux allows advanced control over resources allocated to each hosting account, offering stability and protection against resource abuse. But for site owners, it is essential to understand the imposed limits and monitor usage to avoid unexpected blockages or errors.
If your site frequently reaches these limits, it’s a sign you’ve grown and need a higher package – such as a VPS or even a dedicated server.