Mac No Space on Hard Drive but When Delete Items It Is Taken Up Again

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Adding a new difficult drive or solid-land bulldoze to your Linux calculator? You'll need to edit your fstab file. A lot of people discover the very idea scary. Yep, it's disquisitional that you get it right, but armed with the right cognition, information technology actually isn't difficult. Nosotros step you through the process of editing your fstab file to integrate your new drive into your file system.

fstab, the File Systems Table

Although calculation a new hard bulldoze to a Linux computer isn't too complicated, it can exist a little confusing the first fourth dimension you lot try. Yous connect up the hardware, ability on the computer, and log in to the operating system. Just you cannot see your new drive anywhere. Why doesn't information technology show upwardly? How do you become Linux to "meet" the drive and then you can starting time to configure it?

Actually, Linux has seen your hardware, but it doesn't readily announce it. Or even give you lot a hint that information technology has constitute your new hardware. You have to interrogate Linux to obtain the data you're going to demand to put into your fstab file.

Hither'south how to set up upwards your new hard drive so that Linux—and you—can run into it and use it. There are 2 parts to the process. The first office is doing some reconnaissance to identify the hard bulldoze and to assemble some information on it. The second part is editing the fstab file, using the information nosotros've gathered in the reconnaissance stage.

Finding Your New Bulldoze

We're adding two new drives to this organization. 1 is a 32 GB mechanical difficult bulldoze (Hard disk), and the other is a sixteen GB solid-state drive (SSD).

We need to know that Linux tin can see them, and what block devices Linux is using for them. In Linux and Unix-like operating systems, a cake device is a special file that acts as an interface to a device that data can be read from and written to (unless it is read-simply). Block devices oftentimes stand for a mass-storage unit of some kind (for case, a partition on a hard disk or a CD-ROM. They are created in the /dev directory.

Nosotros can use the lsblk command to list the block devices connected to your Linux computer.

lsblk

The output from lsblk is in columns.

The columns are:

• Name: This is the device name. Devices names that start "sd" and are followed by a letter stand for SCSI hard disks. The letter of the alphabet identifies private hard disks, with "a" being the showtime, "b". being the second and so on. If there is a number appended, it indicates a partition. For case, "sdb2" would be sectionalization 2 on the second SCSI difficult drive.
• Maj:Min: This column holds the major and minor numbers of the device. The major number indicates the type of the device (or, more precisely, the type of driver used to talk to that device). The minor number is a count of the number of devices of that type.
• Rm: This cavalcade shows whether the device is removable or not. Annotation that device sr0 has a value of 1, indicating it is removable. This is a CD-ROM drive.
• Size: This is the amount of data that tin can be stored in the device.
• Ro: This column will show 1 for read-only devices and 0 for read-write devices. The loop devices are all read-only.
• Type: This identifies the blazon of device. The "deejay" entry ways a deejay drive, the "part" entry stands for partition, and "rom" means Read-Only Memory (CD-ROM).
• Mountpoint: This shows the point in the file system at which this device is mounted. If this is blank, the device is not mounted.

In the screenshot in a higher place, you lot can see that the loop devices are all given a major number of vii (significant a loopback, or loop, device), and the minor numbers but increment past one each time. loop devices are used with the squashfs file system. A squashfs file system is created each fourth dimension an application is installed using the snappy package management system.

The SCSI hard drives are given names similar sda, sdb, and sdc, and all have a major number of viii (SCSI hard drive). The minor numbers are grouped in xvi's. The small-scale numbers for the first drive, sda , run from 0 to fifteen. The 0 represents the physical drive, and the minor number of 1 represents the outset partitioning on that bulldoze. For the second drive, sdb , the minor numbers run from 16 to 31. xvi represents the physical drive, and 17 represents the kickoff segmentation on that drive. The next sixteen numbers, 32 to 47, are used for the minor numbers ofsdc , and so on.

Other mutual major numbers are iii (for a IDE difficult drive) and 11 for CD-ROMS.

Actually, the /dev/sr0 fashion for SDCSI CD-ROM drives is deprecated. The approved format is /dev/scd0. Despite that, the/dev/sr0 format was still in employ on all of the machines used to research this commodity.

The kernel documentation contains a long listing of all values that the major and small-scale numbers tin take. Information technology'due south a surprisingly long list.

To de-ataxia the output from lsblk nosotros tin can use grep to select merely the items of involvement to united states. We know nosotros've not added a loop device, so let's select all of the SCSI difficult drives. nosotros know these will take "sd" in their names.

lsblk | grep sd

This command volition cause grep to print simply lines that accept "sd" in the. On our test auto, we meet:

Then, we have iii SCSI drives. The first ane, /dev/sda , is mounted at the root of the file system, /. The other two are not mounted at all, which is to be expected for brand new drives. We can see that drive /dev/sdb is 32 GB in size, which means information technology is our traditional mechanical drive. Drive /dev/sdc is xvi GB in size, and this is our SSD drive.

Actually, as this is a virtual reckoner, these are also virtual disks. So the SSD is showing up just like a SCSI mechanical drive. On my regular desktop my NVMe SSD shows up equally /dev/nvme0n1, and the first partitioning on it is /dev/nvme0n1p1. Its major number is 259. Those differences don't alter what nosotros've got to do in thefstab file, but exist aware if you lot have an SSD, information technology isn't going to testify up every bit a physical drive.

Also, your drives probably won't have a partitioning on them if they are brand new. You can apply fdisk to create a partitioning if required.

RELATED: How to Use Fdisk to Manage Partitions on Linux

Identifying Rotating and Non-rotating Drives

If we use the -o (output) selection with lsblk and add together the ROTA (rotating) column to the brandish, lsblk will use a 1 to indicate a rotating storage device (mechanical drive) and a 0 to indicate a not-rotating storage device (solid-state drive).

lsblk -o +ROTA | grep sd

We get an extra column on the right of the display, which is the ROTA (rotating) column. As y'all can run into, the "SSD" has a 0 for the device and division. That makes sense because an SSD is a non-rotating storage device.

Mounting The File Systems

Before nosotros first thinking virtually the fstab file, let's cheque that nosotros can mount the drives by hand. This way, if something doesn't work when we utilize the fstab file, we'll know the problem must be our syntax and not a problem with the drive itself.

We'll create some temporary mount points in the /mnt directory. You'll need to use sudo , and you'll be prompted for your password.

sudo mkdir /mnt/scsi

sudo mkdir /mnt/ssd

Now let'south mount the SCSI drive on the new mount point. We'll use the mount control in its simplest form. We'll tell it the proper name of the partition we want to mount, and the mount point we want it mounted on. mount will mount the file organisation on that partition at the mount point we specify.

We're specifying the partition that holds the file organisation, not the drive, and so be sure to include the digit for the division, in this case, "1".

sudo mount /dev/sdb1 /mnt/scsi

If all goes well, in that location'll be no response from mountain. You're silently returned to the control prompt.

Mounting the SSD is only every bit simple. Nosotros tell mount which partition on which device to mountain, and the mountain point to mount it on.

sudo mount /dev/sdc1 /mnt/ssd

Once again, silence is golden.

RELATED: How to Mount and Unmount Storage Devices from the Linux Terminal

Checking the Mounts

To verify that the mounts have taken place, nosotros'll use lsblk again. Nosotros'll pipe its output through grep and select the "sda1", "sdb2", and "sdc1" entries.

lsblk -o +ROTA | grep sd[a-c]1

mount shows us the three mounted partitions. That's the two we've simply mounted and the original division mounted on /.

The partition /dev/sdb1 is mounted on /mnt/scsi, and is on a rotating storage device. The partition/dev/sdc1 is mounted on /mnt/ssd and is on a non-rotating storage device. All seems well.

Now we need to configure the fstab file so that these devices are mounted each time the figurer is started up.

The fstab File

The fstab file contains an entry for each file arrangement that is mounted when your reckoner is restarted. Each entry is made upwardly of 6 fields. The fields are:

• File arrangement: Not, every bit its name would suggest, the type of file system on the partition (that's what the type field is for). This is the identifier for the partition that should exist mounted.
• Mount point: The location in the filesystem at which you lot wish to accept the partition mounted.
• Type: The type of file organisation on the sectionalisation.
• Options: Each file organisation can have options specified to plow on or off functionality.
• Dump: A reference to an all-just obsolete means of bankroll up file systems, where the entire file system was "dumped" to tape.
• Laissez passer: This is the "passing" flag. It tells Linux which partitions should exist checked for errors using fsck , and in which order. Your principal boot and operating system partition should be one, and the residual can exist fix to 2. If the flag is fix to naught, it means "don't check at all." If your file organization isn't a journaling file arrangement (such as ext2 or FAT16/32, for example), it is all-time to turn this off past setting it to 0.

These fields must exist specified in this guild, and they must have a space or a tab between them. Finding the values for these fields tin be daunting, particularly the values for the "options" field. The "options" field options must be in a comma-separated list with no spaces between them.

The man page for each file system will list the options that can be used. ext4 has about twoscore options.  Here are some of the more common options:

• Auto: The file system will exist mounted at boot time, automatically.
• Noauto: The file organisation is only mounted when you enter the mountain -a control.
• Exec: The execution of binaries is allowed on this file system.
• Noexec: The execution of binaries is non allowed on this file organization.
• Ro: The file system should be mounted as read-only.
• Rw: The file arrangement should be mounted every bit read-write.
• Sync: File writes should be conducted immediately and not buffered. All-time reserved for floppy disks, if anyone is withal using them. Incurs a operation penalty.
• Async: File writes should exist buffered and optimized.
• User: Any user is allowed to mount the file system.
• Nouser: The root user is the just user who tin mountain this file system.
• Defaults: This is a shorthand way of specifying a set up of common settings: rw, suid, dev, exec, motorcar, nouser, and async).
• Suid: Allows the operation of the suid and sgid bits. The suid fleck is used to allow a file to be executed as root, past a normal user, without giving the user full root privileges. When the sgid flake is assault a directory, files and directories created within that directory take their group buying set to that of the directory, not to the group of the user who created them.
• Nosuid: Do not permit the utilise of the suid and sgid bits.
• Noatime: – Do not update the file admission times on the file organisation. This can help performance on old hardware.
• Nodiratime: Do not update the directory access times on the file system.
• Relatime: Update file admission times relative to the file modified time.

The "defaults" choice is a practiced opening gambit. You can add or remove further options if some fine-tuning is required. If merely at that place was a neat style to get the settings you need, in the social club you need to enter them into the fstab file.

Enter the mtab file.

The mtab File

The mtab file is the list of currently mounted file systems. This is in dissimilarity to the fstab file which lists the file systems that should exist mounted at boot time. The mtab file includes manually mounted file systems. We've already mounted our new drives, and so they should show up in the mtab file.

We tin run across the contents of the mtab file using cat. We'll restrict the output past piping it through grep and looking at /dev/sdb1 and /dev/sdc1 only.

cat /etc/mtab | grep sd[b-c]i

The output shows the mtab entries for these two partitions.

Nosotros could lift those values and drop them straight into the fstab file, making sure there was a space or a tab betwixt each field. And that would be that. The drives would be mounted when we rebooted.

At that place are two caveats to that. One is the mount point. We created temporary mountain points just to evidence we could mount the new partitions on the new drives. Nosotros'd need to enter the existent mount points instead of our temporary ones—if they were unlike.

The second caveat is, if we use the settings from the mtab file, we'll be using the block device file as the identifier for each partition. That would piece of work, simply the values /dev/sda and /dev/sdb then on are at risk of changing if new mass storage hardware is added to the computer. That would mean the settings in thefstab file would be incorrect.

Each partition has a Universally Unique Identifier (UUID), which we tin use to identify the segmentation. This will never alter. If we employ the UUID to identify the partitions in the fstab file, the settings will always remain accurate and truthful.

If you lot are using your new partitions as part of a Redundant Array of Inexpensive Disks (RAID) system, cheque with the documentation for that system. Information technology might specify that you must apply the cake device identifier instead of the UUID.

Finding a Partition'due south UUID

To discover the UUID of a partition, we tin can apply blkid to impress the attributes of the cake devices. Nosotros'll limit the output to our two new partitions on our new drives:

blkid | grep sd[b-c]1

The output includes the UUID for each division.

The PARTUUID is a course of UUID that can be used with the GUID Sectionalisation Tables (GPT) partitioning method (if y'all're not using the Main Kicking Tape (MBR) partitioning method).

Editing the fstab File

Open the fstab file in an editor. Nosotros're using gedit, an easy to apply editor found in most Linux distributions.

sudo gedit /etc/fstab

The editor appears with your fstab file loaded in it.

This fstab file has two entries already in it. They are the sectionalization on the existing hard drive /dev/sda1, and the swap file system. Be careful not to alter these entries.

We need to add two new entries to the fstab file. 1 for the partition on the SCSI drive and ane for the partition on the SSD drive. We'll add the SCSI partition showtime. Note that lines that start with a hash # are comments.

• In the "file system" field, nosotros'll use the UUID that blkid retrieved for united states earlier. Start the line with "UUID=" and then paste the UUID. Press space or tab.
• For the "mountain point" field, nosotros're going to utilise the mount point nosotros created earlier,/mnt/scsi. You'd use the appropriate mount signal from your system. Press space or tab.
• For "type" we're going to enter ext4 , which is the type of file arrangement on our segmentation. Press space or tab.
• In the "options" field we'll employ the options that nosotros retrieved using cat /etc/mtab. These are "rw,relatime". Press space or tab.
• The "dump" field is gear up to aught. Press infinite or tab.
• The "pass" field is gear up to naught.

Now we'll add together the fstab entry division on the SSD bulldoze on a separate line.

• In the "file system" field, we'll enter the UUID that blkid retrieved for the division on the SSD drive. Start the line with "UUID=" and then paste the UUID. Press space or tab.
• For the "mount indicate" field, nosotros're going to use the mountain betoken we created earlier,/mnt/ssd. Press infinite or tab.
• For "blazon" we're going to enter ext4 , which is the type of file organization on our sectionalisation. Printing space or tab.
• In the "options" field—just to make the two new entries different in our example—we'll use the "defaults" option. Printing space or tab.
• The "dump" field is set to zero. Printing space or tab.
• The "pass" field is set to nil.

Relieve the file and close the editor.

RELATED: How to Edit Text Files Graphically on Linux With gedit

Testing fstab Without Rebooting

We can unmount our new drives and so strength a refresh on the fstab file. The successful mounting of our new partitions will verify that the settings and parameters we've entered are syntactically correct. That means ourfstab file should exist processed correctly during a reboot or ability-up sequence.

To unmount the SCSI bulldoze, employ this control. Note that there is just one "n" in "umount":

sudo umount /dev/sdb1

To unmount the SSD drive, employ this control:

sudo umount /dev/sdc1

At present nosotros'll employ lsblk to check whether these block devices are mounted.

lsblk | grep sd

And we meet that the block devices are nowadays in the computer, just not mounted anywhere.

We can utilize the mountain control with the -a (all) option to remount all the file systems in fstab.

sudo mount -a

And nosotros tin check once more with lsblk to see if our new partitions are now mounted:

lsblk | grep sd

Everything is mounted where it should be.  All we accept to do now is alter the ownership of the mount points, otherwise root will be the but 1 who can admission the new storage devices.

Nosotros can practice this hands using chown . This is the command for the SCSI mount point:

sudo chown dave:users /mnt/scsi

And this is the command for the SSD mount signal:

sudo chown dave:users /mnt/ssd

We can at present reboot our estimator with confidence, knowing that the partitions nosotros've added will be mounted for the states, and nosotros have access to them.

Non That Scary Later on All

All the hard work is in the reconnaissance phase—and that wasn't hard either. Editing the fstab file one time y'all've gathered the data yous need is a breeze. Grooming is everything.

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Source: https://www.howtogeek.com/444814/how-to-write-an-fstab-file-on-linux/

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