Partitioning divides a hard drive into separate, discrete sections called volumes. Partitioning an external hard drive on a Mac provides several key benefits. It allows you to organize files, make backups easier, isolate sensitive data, create bootable volumes, and more. This article will provide an overview of partitioning – what it is, why it can be useful for Mac users, and the main reasons for partitioning an external drive.
Increase Performance
Partitioning an external hard drive on a Mac can help improve performance by allowing faster seeks between partitions. When a hard drive is partitioned, each partition is treated as a separate volume by the operating system. This means that when data is accessed from one partition, the drive heads only need to move within that partition rather than scanning the entire drive to find the requested files (source: https://www.quora.com/Does-partitioning-your-hard-drive-have-any-effect-on-performance). The reduced distance the heads need to travel results in faster access times.
However, some sources indicate that partitioning can reduce overall performance in cases where data is accessed frequently across multiple partitions. This is because the drive heads may need to move back and forth between partitions more often (source: https://www.minitool.com/partition-disk/does-partitioning-affect-performance.html). So partitioning is most likely to improve performance when data access is concentrated within each partition.
In general, partitioning will optimize performance if you separate data types that are accessed together onto the same partition. For example, putting applications on one partition and documents on another. This allows faster access than if they were mixed together. But constantly accessing data across partitions may negate these gains.
Organize Files
Using partitions on an external hard drive is a great way to logically group and separate your files. You can create different partitions for different categories or purposes. For example, you could have one partition for work files, another for personal files, one for your photo library, and so on. This makes it easy to find what you’re looking for and keeps things neat and organized.
As recommended in this Quora post, start by thinking about the main folders you want for broad categories. For photos, videos, music and other media, you may want a separate partition just for those large files. Partitions also help isolate sensitive documents or financial information that you want to restrict access to.
Overall, partitioning removes clutter on your external drive and lets you group related files together in their own section. This organization system helps you quickly navigate your drive and find what you need.
Isolate Sensitive Data
One of the key reasons to partition an external hard drive on a Mac is to isolate and secure sensitive files. By creating an encrypted partition, you can store confidential documents, financial records, or other private data separately from the rest of your drive (IEEE, 2022). This prevents unauthorized access if the rest of the drive is compromised.
With macOS’s built-in Disk Utility, it’s simple to create an encrypted APFS (Apple File System) volume when partitioning. The partition will be locked with a password, ensuring no one can view the contents without authentication. All data written to the partition will be encrypted using advanced AES-XTS encryption (Airbyte, 2023).
By storing financial documents, tax records, customer data, or other confidential files in an encrypted partition, you can secure these sensitive assets while still using the external drive for more general storage needs. Proper partitioning helps you manage access and isolate risks.
Quick Backups
One of the key benefits of partitioning an external hard drive for Mac is to create a dedicated partition just for Time Machine backups or disk cloning. Time Machine is Apple’s built-in backup software that makes it easy to regularly backup your entire Mac system onto an external drive (Apple Support). By creating a partition just for Time Machine backups, you can isolate and protect this important backup data.
Setting up a dedicated Time Machine partition ensures there will always be plenty of space on the drive for system backups, without having to worry about filling the drive with other files and data. It also makes the backup process simpler as Time Machine will just focus on that one partition. When it’s time for a backup, Time Machine will quickly identify changed files and backup everything to the designated partition.
Having a separate partition for Time Machine is recommended over using the entire external drive for backups. This is because it still gives you room to store other files and data on separate partitions. Overall, a dedicated Time Machine partition provides a fast, streamlined way to safeguard your system with automatic and ongoing backups.
Bootable Volumes
One reason to partition an external hard drive is to create bootable volumes for diagnostics, troubleshooting, or installing new operating system versions. This allows you to boot directly from the external drive to tools like disk utilities, Windows installation media, or macOS recovery partitions.
To create a bootable volume on an external hard drive for Mac, you can use the built-in Disk Utility application. Simply connect the external drive, open Disk Utility, select the drive, click “Partition”, set the format to “Mac OS Extended (Journaled)”, and adjust the partition size as needed. Be sure to name the partition something recognizable. Then click “Apply”.
Next, acquire the OS installer image (like a Windows ISO file), and use a utility like Rufus to write the image onto the new partition. Rufus formats the drive and makes it bootable so you can run diagnostics or install the OS from the external drive.
With a bootable volume on an external hard drive, you can boot to various utilities when needed without impacting the main internal drive. It serves as a useful troubleshooting tool.
Partition Schemes
The two main partitioning schemes for hard drives are Master Boot Record (MBR) and GUID Partition Table (GPT). MBR is the older standard that was commonly used before larger hard drives became available. GPT is newer and has several advantages, especially for external hard drives.
MBR has a 2TB size limit per partition, so it cannot be used with very large external drives. MBR also only supports up to 4 primary partitions per disk. GPT has much higher limits and supports unlimited partitions on a single disk. This flexibility makes GPT better suited for setting up multiple partitions on an external drive.
GPT uses globally unique identifiers to define partitions, making it more resilient against data corruption. MBR stores critical data structures in only one place, increasing the risk of corruption. GPT stores multiple backup copies for redundancy.
For bootable external drives, GPT has the advantage of being compatible with UEFI firmware which is commonly used on modern PCs. MBR can have issues booting on UEFI systems. GPT also supports additional security features like encryption that are not available with MBR.
In summary, GPT is generally considered superior to MBR for external drives today, thanks to its flexibility, resilience, and compatibility. The main limitation of GPT is compatibility with older BIOS-based systems that do not support UEFI. But for most modern external drive uses, GPT is the preferred choice.
Creating Partitions
Partitioning an external hard drive on a Mac is a straightforward process using Disk Utility. Here are the steps:
- Open Disk Utility on your Mac. You can find it using Spotlight or in the Utilities folder in Applications.
- In the sidebar, select the external drive you want to partition.
- Click the Partition button in the toolbar.
- Select the number of partitions you want to create using the + and – buttons below the pie chart.
- Give each partition a name and select the format (APFS or exFAT are common for external drives).
- Click Apply to create the partitions.
The partitions will be created on your external drive without losing any data. You can manage and resize partitions later if needed using Disk Utility.
For more details, see Apple’s guide to partitioning a disk.
Managing Partitions
There are a few different tools available for managing partitions on a Mac.
The built-in Disk Utility app allows you to create, resize, delete, rename, and format partitions. Disk Utility is simple and easy to use for basic partition management (https://recoverit.wondershare.com/mac-tips/mac-partition-manager.html).
For more advanced partition management, third-party apps like Paragon Hard Disk Manager (https://discussions.apple.com/thread/250164953) offer additional features like non-destructive partitioning, bootable backups, and data recovery tools. Other popular third-party partition managers for Mac include iPartition and Stellar Partition Manager.
Third-party managers provide more flexibility and control over partitions than Disk Utility. They allow you to resize partitions without erasing data, clone partitions for backups, merge partitions, and perform other advanced operations. The additional features can be useful for power users managing multiple partitions.
Conclusion
In summary, partitioning an external hard drive on a Mac provides several key benefits. Partitioning allows you to organize files and data, isolate sensitive information, quickly backup or restore your system, boot multiple operating systems, and better manage your available disk space. The two main partition schemes for Mac are GUID Partition Table (GPT) and Apple Partition Map (APM), with GPT being newer and preferred. Common use cases for partitioning an external drive include creating separate volumes for personal files, work files, Time Machine backups, a Windows partition for Boot Camp, or even having multiple bootable macOS installations for testing purposes. While partitioning adds some complexity, the flexibility and organization it provides makes it a worthwhile endeavor for advanced Mac users with sizable external drives. With the proper planning and tools like Disk Utility, partitioning an external hard drive on a Mac is a straightforward process that unlocks additional functionality.