Disk management

A disk controller is a hardware device that manages the operation of hard drives and solid-state drives in a server. It facilitates communication between the server's central processing unit (CPU) and the drives, controls data reading and writing, and is responsible for RAID (Redundant Array of Independent Disks) management functions.

Why are there different numbers of disks and possible RAID levels?

Entry-level servers, such as the Dell PowerEdge R210, typically come with fewer disks and support less memory, which is sufficient for small business solutions. On the other hand, models like the Dell PowerEdge R730xd support a larger number of disks and greater memory capacity, offering extensive scalability for large corporate tasks.

We offer server models that support building RAID arrays at various levels. The most commonly used are RAID 0 and RAID 1:

• RAID 0: significantly boosts performance by writing data in parallel across multiple disks but does not provide data protection. Requires a minimum of 2 disks
• RAID 1: ensures data mirroring, significantly enhancing reliability but losing half of the available capacity. Requires a minimum of 2 disks

How to configure RAID

The Customer Portal provides the ability to configure server disks using RAID technology both when ordering a dedicated server and after provisioning one. This functionality becomes available when:

• The server chassis and the selected operating system support RAID technologies
• More than one disk of the same size is selected in the server slots

To configure RAID, complete the following steps:

1. Select the server where RAID needs to be configured.
2. On the server configuration page:
   • Scroll to the Operating system section if the server is being ordered
   • Scroll to the Disk upgrade section and click Upgrade if the server is already ordered
3. Select the operating system if the server does not have one.
4. In the RAID section:
   • Automatic settings: select the RAID level for creating an array with automatic settings and proceed to step 8
   • Advanced settings: leave Advanced settings (More HDDs, custom partitioning & more) selected and scroll to the slots section
5. In the slots section, assign at least two free slots with drives of the same size and mark the checkbox next to each disk.
6. Click Build RAID.
7. In the pop-up window, select the RAID level. The Make bootable option means that the operating system will be installed and boot from this RAID array.
8. Click Save.
9. Configure partitions if required. More details can be found here.
10. Complete the server configuration by clicking Order upgrade or Save.
11. Confirm the action in the pop-up window by clicking I'm sure, reinstall OS.
12. Enter your account password in the pop-up window and click Continue.

How to mount a disk drive

1. In the left-hand menu, navigate to Dedicated Servers → Manage.
2. Choose the server and click Details.
3. Next to the Disk upgrade item, click Upgrade.
4. To choose a disk for mounting, find an available slot on the page and click Replace drive, or choose the default disk provided by the Customer Portal.
5. Click Mount drive. A Disk Mount Overview section will appear, allowing you to manage the disk partitions.
6. Choose a preferred date and time slot for the upgrade.
7. To apply the mounting, click Order upgrade.

Disk partitions

Linux/Unix-based systems

These settings show the disk space allocation on the main boot disk, including the allocation for boot files, virtual memory, and the main file system.

A mount point (target) is a location in the file system where a file system or storage device is attached.

When a drive is mounted, the operating system links its contents to a specific directory in the file system tree. This allows users and applications to interact with the data on the device as if it were part of the main file system.

Examples of mount points:

• /boot — the mount point for the partition containing boot files. This is usually a separate small partition necessary for booting the operating system. The ext4 file system is commonly used for Linux
• / — the root mount point where the entire Linux file system resides. All other files and directories are located within this hierarchical tree
• /home — often used as a mount point for a separate partition containing user home directories
• /mnt/usb — can be used for mounting USB devices such as flash drives

Mount points allow for the organization and management of access to different file systems and devices within a unified namespace.

What is a target?

This configuration window displays the interface for setting up partitions in Linux, where you can select the mount point (target) for a new partition on a non-boot disk.

Here is a brief description of the available mount points:

• /mount/ — a general folder for mounting additional file systems or devices on a non-boot disk. Used for temporary or permanent attachment of various devices
• /home — the directory where user home directories are located. Typically used for storing user data, settings, and files
• /tmp — the directory for temporary files. The system and applications use it for temporary data storage, which can be deleted after a reboot
• /var — the directory for variable data. This includes log files, mail spools, databases, and other frequently changing files
• /var/log — a subdirectory in /var, specifically designed for storing log files. System and application logs are recorded here
• /usr — the directory for installing software and user utilities. It houses most of the system's applications and utilities
• /opt — the directory for additional software packages and applications that are not included in the standard distribution packages. Used for installing third-party software

These mount points allow you to organize and structure the file system on a non-boot disk, distributing various types of data across the appropriate directories.

When do I need to change it?

Changing the target (mount point) for a new partition may be necessary in the following cases:

1. Separating user data: mount to /home to keep user data separate from system files
2. Improving performance: mount to /var or /var/log to isolate logs and variable data, reducing load on the main system
3. Security and stability: mount /tmp on a separate partition to prevent attacks and avoid filling up the main partition
4. Disk space management: mount to /usr or /opt for additional software and applications
5. Custom storage requirements: mount to /mnt/ for applications needing dedicated storage space
6. Backup and restore: separate partitions simplify backup and restore processes
7. Multi-disk configurations: distribute data across multiple disks by mounting partitions on secondary disks, such as /mnt/data

Changing the mount point helps optimize performance, enhance security, and simplify system management.

What is swap?

Swap is a designated area on the disk that the operating system uses as additional virtual memory. This allows the server to continue operating even if the physical RAM is exhausted.

How does swap work?

When the RAM is full, the operating system moves less frequently used data from the RAM to the swap space on the disk. This frees up RAM for more critical tasks. When these data are needed again, they are moved back to the RAM.

Windows OS

In Windows, mount points perform a similar function but are organized somewhat differently compared to UNIX/Linux systems. Here are the main concepts regarding mount points in Windows:

• Drive letters: mount points are typically represented by drive letters, such as C:, D:, E:, etc. Each storage device or partition usually receives its own drive letter. For example, the main disk where the operating system is installed is often designated as C:
• Mount points: you can also use mount points to attach a new partition or disk to an existing directory in the file system. This is similar to the method used in Linux. For instance, a new disk can be attached to the directory C:\Data instead of being assigned a separate drive letter
• C:\Boot folder: boot files are typically stored in the C:\Boot folder or other system directories such as C:\Windows\Boot
• Virtual memory (pagefile): the equivalent of the swap partition is called pagefile. It is located in the root directory of the main disk, usually as C:\pagefile.sys, and is used for virtual memory

Key points:

• Drive letters (e.g., C:, D:) are used to access main partitions and devices
• Mount points can be used to attach partitions to existing directories
• Boot files are stored in system folders (e.g., C:\Boot)
• Virtual memory is stored in pagefile on the main disk

Thus, mount points in Windows and Linux serve similar functions but are organized and represented in different ways.