{"id":620,"date":"2020-02-20T19:49:04","date_gmt":"2020-02-20T18:49:04","guid":{"rendered":"https:\/\/codedoneright.eu\/?page_id=620"},"modified":"2022-05-09T19:35:52","modified_gmt":"2022-05-09T18:35:52","slug":"mount-disk","status":"publish","type":"page","link":"https:\/\/codedoneright.eu\/?page_id=620","title":{"rendered":"Mounting external storage"},"content":{"rendered":"\n
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Space for your data<\/figcaption><\/figure><\/div>\n\n\n\n
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Word of caution before you begin<\/h4>\n\n\n\n

The biggest hurdle you will encounter when mounting disks to Raspberry Pi is the power usage. Some disks, require more power than others. This is not an issue with a regular PC, as it delivers greater amount of power than needed for using a disk, but Raspberry will have problems. <\/p>\n\n\n\n

If you are experiencing any difficulties with using a disk, such as video stuttering or general access trouble, then consider changing the case for a powered one.<\/p>\n\n\n\n

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How Linux treats drives<\/h4>\n\n\n\n

Contrary to Windows, Linux treats partitions as folders. They can be placed anywhere you want them to be, instead of being constrained to a lettered drive. If you want to put the partition directly on the root system, you can do it. If you want to mount it in \/var\/<\/em> folder, you can do that as well. <\/p>\n\n\n\n

Windows automatically mounts any partition that it detects, if you plug a pendrive to your PC, it just shows up. Windows streamlines the process and correctly assumes you want it to show up immediately, and acts by mounting the partition. This is not the case on Linux.<\/p>\n\n\n\n

Upon plugging a drive to your Linux machine it is acknowledged by the system, but partitions are not mounted. User can choose where to mount a partition, as they are treated as additional folders for you to use as far as the system is concerned. <\/p>\n\n\n\n

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Creating a mount folder<\/h4>\n\n\n\n

Now that you know how Linux treats drives, it is time to decide where you want to mount it. It can be anywhere, almost, but remember that the drive should be mounted in an easily accessible place and navigating to \/var\/john\/drives\/disk1\/partition1\/<\/em> might be inconvenient. I am not saying you cannot mount it there, but you can mount it a more user friendly place.<\/p>\n\n\n\n

For the purpose of this tutorial let us assume that you want your drive accessible from the folder \/drive1<\/em>. Run the following commands<\/p>\n\n\n\n

sudo mkdir \/drive1\nsudo chmod -R 775 \/drive1<\/code><\/pre>\n\n\n\n
The above will create a folder drive1<\/em> right on the root of your filesystem. any time you want to access it you can just type \/drive1<\/em> in the path. Modify chmod <\/em>accordingly if you have a specific use for the drive. Otherwise leave it at 775<\/em>.  Setting chmod <\/em>to 777 <\/em>will give everybody full access.<\/p>\n\n\n\n
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Proper file system<\/h4>\n\n\n\n
Partitions should be formatted to ext4<\/em> file system, so that Raspberry can read it without any problems (ext2<\/em> if using an SD card). It is possible to use other file systems such as NTFS. For convenience, it is best to use the native Linux ext4<\/em> file system. Learn how to format your drives here<\/a>.<\/p>\n\n\n\n
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Listing drives<\/h4>\n\n\n\n
In order to mount a drive you have to know what drives are available for mounting. Run the following command <\/p>\n\n\n\n
sudo fdisk -l<\/code><\/pre>\n\n\n\n
At the bottom of output you should find an entry similar to the following<\/p>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n
Entry Disk \/dev\/sda<\/em> shows the disk. However, you should mount the partition, and not the disk itself. <\/p>\n\n\n\n
Partitions will be listed as \/dev\/sdaX<\/em> where X<\/em> is the number of a partition. <\/p>\n\n\n\n
If you have only one, you will see just \/dev\/sda1<\/em>, like on the screenshot above.<\/p>\n\n\n\n
If you have more drives, the second will be shown as \/dev\/sdb<\/em> with partitions starting from \/dev\/sdb1<\/em>, third will be \/dev\/sdc<\/em> etc.<\/p>\n\n\n\n
fdisk<\/em> shows an overview of drives available to you and will allow to identify partitions belonging to a particular drive. <\/p>\n\n\n\n
In case you have trouble identifying disks you can google the disk model to make sure which \/dev\/sdX<\/em> is which disk.<\/p>\n\n\n\n
<\/div>\n\n\n\n
Mounting a partition<\/h3>\n\n\n\n
Run the following command to mount your partition<\/p>\n\n\n\n
sudo mount \/dev\/sda1 \/drive1<\/code><\/pre>\n\n\n\n
Now your disk is available through \/drive1<\/em> folder. Hardest part was finding the correct partition to mount.<\/p>\n\n\n\n
<\/div>\n\n\n\n
Mounting a partition to a folder with files<\/h3>\n\n\n\n
It is possible to mount a partition to a folder that already contains files. System will not prevent you from doing so, however, bear in mind that those files will not be accessible as long as the partition is mounted in that particular folder.<\/p>\n\n\n\n
<\/div>\n\n\n\n
Unmounting a drive<\/h3>\n\n\n\n
If for some reason you want to unplug your drive from a running system, it is best to do it safely by unmounting it first. Unless you physically unplug it, the drive will be accessible to your system if you want to mount it again or modify somehow (e.g. format a partition).<\/p>\n\n\n\n
The biggest difference is that it will not be readable or writeable, so unplugging it will not affect data, and in turn you will avoid any corruption that could happen should you unplug a drive that is in the process or writing to disk.<\/p>\n\n\n\n
CAUTION <\/strong>remember that if you have multiple partitions mounted on a given drive, you should unmount all of them before unplugging it the drive!<\/p>\n\n\n\n
In order to unmount the drive from the example above, run the following command<\/p>\n\n\n\n
sudo umount \/dev\/sda1<\/code><\/pre>\n\n\n\n
It is now safe to unplug your drive from your machine.<\/p>\n\n\n\n
<\/div>\n\n\n\n
Mounting a drive permanently<\/h4>\n\n\n\n
Since drives have to be mounted manually, upon a system reboot they will not be mounted by default. You can, however, modify this behavior if you have a drive permanently attached to your Raspberry. <\/p>\n\n\n\n
In order to do so, you have to modify the fstab<\/em> file located here<\/p>\n\n\n\n
\/etc\/fstab<\/code><\/pre>\n\n\n\n
But first, you need to gather some more information from your system to be sure that the exact same partition will be mounted to the exact same location every time. If you attach a second drive, depending on USB ports you use, it might take place of your disk in \/dev\/sda<\/em> and consequentially your \/dev\/sda1<\/em> partition might change.<\/p>\n\n\n\n
CAUTION<\/strong> Read warning about unusual partition identifiers below first!<\/p>\n\n\n\n
Run the following command<\/p>\n\n\n\n
blkid<\/code><\/pre>\n\n\n\n
This is the typical result<\/p>\n\n\n\n
\"\"<\/figure><\/div>\n\n\n\n
As you can see at the very bottom we have our \/dev\/sda1<\/em> partition. Take note of the following<\/p>\n\n\n\n