In the Linux ecosystem, mounting and unmounting disks are crucial operations that allow users to access and manage storage devices efficiently. This guide aims to provide a practical approach to understanding and executing these operations, enabling even beginners to handle their storage needs confidently.
Introduction
Mounting is the process of making a storage device accessible to the system by assigning it a specific directory (known as a mount point) in the directory tree. Unmounting, conversely, is the process of detaching the storage device, making it inaccessible to the system.
These operations are fundamental for managing external hard drives, USB drives, and even network storage within Linux, ensuring data integrity and efficient storage access.
How to Mount a Disk in Linux
Mounting can be achieved through the command line, which offers flexibility and power not found in graphical interfaces. Here’s a step-by-step guide:
- Identify the Disk: First, you need to identify the disk you want to mount. Use the lsblk command to list all block devices, including disks and partitions:
lsblk - Create a Mount Point: A mount point is simply a directory where the disk’s contents will be accessible. Create a new directory for your mount point if it doesn’t already exist:
sudo mkdir /mnt/mydisk - Mount the Disk: Now, use the mount command to mount the disk to the mount point you’ve created. Replace /dev/sdx1 with your disk’s identifier and /mnt/mydisk with your mount point:
sudo mount /dev/sdx1 /mnt/mydisk
How to Unmount a Disk in Linux
Unmounting is simpler but equally important. Use the umount command followed by either the mount point or the device name:
sudo umount /mnt/mydisk
Or:
sudo umount /dev/sdx1
Ensuring Safe Unmounting
Sometimes, you might encounter an error stating the device is busy. This usually means a process is still using the mounted device. You can find out which process is causing the issue with the lsof or fuser command:
sudo lsof /mnt/mydisk
Terminate the process or ensure it’s not using the disk before attempting to unmount again.
Advanced Mounting Options
Linux’s mount utility comes with a plethora of options for advanced users. For instance, specifying the filesystem type with the -t option can be necessary for certain disks:
sudo mount -t ntfs /dev/sdx1 /mnt/mydisk
Additionally, options like ro for read-only access or rw for read-write access can be specified with the -o option:
sudo mount -o ro /dev/sdx1 /mnt/mydisk
Automating Mounts with /etc/fstab
For disks that need to be mounted at boot time, Linux provides the /etc/fstab file. Adding an entry here can automate the mounting process, ensuring your disks are always ready when the system starts.
Conclusion
Mounting and unmounting disks in Linux might seem daunting at first, but it’s a straightforward process once you understand the basics. By following this guide, you’re now equipped to manage your disks effectively, whether you’re running a home server, managing an enterprise network, or simply exploring Linux’s capabilities. Remember, with great power comes great responsibility—always ensure you’re mounting and unmounting safely to protect your data.
4 Comments
Good point!
Can I retrieve deleted folder with this process.
I have a dedicated server provided to me by 1and1. I started migrating websites to the server only to realise that I am running out of disk space. I had to clear my backups in order to continue migrating my sites. I thought this to be weird as the server comes with 4T of disk space.
On accessing the system via ssh. I see the following setup by 1and1:
#vgdisplay
— Volume group —
VG Name vg00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 8
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 1
Act PV 1
VG Size <54.00 GiB
PE Size 4.00 MiB
Total PE 13823
Alloc PE / Size 11520 / 45.00 GiB
Free PE / Size 2303 / <9.00 GiB
VG UUID CmLv2a-xKAn-cFQQ-K4TU-f5y2-UK8K-Uv1PO9
— Volume group —
VG Name hdd
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size <3.58 TiB
PE Size 4.00 MiB
Total PE 938308
Alloc PE / Size 1024 / 4.00 GiB
Free PE / Size 937284 / <3.58 TiB
VG UUID Pv2xfH-zkE1-hgH0-dOzZ-FgKp-IobS-5C2zea
Also #pvscan reveals this:
PV /dev/sda3 VG vg00 lvm2 [<54.00 GiB / <9.00 GiB free]
PV /dev/sdb1 VG hdd lvm2 [<3.58 TiB / <3.58 TiB free]
Can someone please let me know the best process for getting this unused free space in to the root volume group? I have searched and seen so many different answers. As I have already started migrating a number of websites. I cannot afford to break the server, otherwise I would have a fiddle, break, and learn as I usually do.
Just a thought failed to mention this is Hardware Raid 5
Update to question below:
#pvdisplay
— Physical volume —
PV Name /dev/sda3
VG Name vg00
PV Size <54.00 GiB / not usable 2.81 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 13823
Free PE 767
Allocated PE 13056
PV UUID 6J06IE-52et-s8aV-bXk0-alud-0N1v-NEwHHr
— Physical volume —
PV Name /dev/sdb1
VG Name hdd
PV Size <3.58 TiB / not usable <3.78 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 938308
Free PE 937284
Allocated PE 1024
PV UUID bGlBQQ-gnmF-gOav-VTfj-np5R-sAKs-YNxemq
I would like to reduce the physical volume in /dev/sdb1 by 2 or 3TB and increase /dev/sda3 by the same amount. Can this be done? If so what process would I need to follow?
If not I noticed mentioned in the replies "Migrating the websites to hdd" What process would I have to follow and what are the implications of doing this?
Logical Volumes:
— Logical volume —
LV Path /dev/vg00/usr
LV Name usr
VG Name vg00
LV UUID sRvgQ3-W80K-AJQD-lZid-fqF3-1KTY-JH2Ul0
LV Write Access read/write
LV Creation host, time ,
LV Status available
# open 1
LV Size 15.00 GiB
Current LE 3840
Segments 2
Allocation inherit
Read ahead sectors auto
– currently set to 8192
Block device 253:0
— Logical volume —
LV Path /dev/vg00/var
LV Name var
VG Name vg00
LV UUID xWSCRG-vBPH-JLha-yJ8X-3zMP-WgRG-AOoJqO
LV Write Access read/write
LV Creation host, time ,
LV Status available
# open 1
LV Size 31.00 GiB
Current LE 7936
Segments 3
Allocation inherit
Read ahead sectors auto
– currently set to 8192
Block device 253:1
— Logical volume —
LV Path /dev/vg00/home
LV Name home
VG Name vg00
LV UUID 2foQrE-Wy3C-Ig1Z-zIDy-tTFQ-YyO5-ayHBZl
LV Write Access read/write
LV Creation host, time ,
LV Status available
# open 1
LV Size 5.00 GiB
Current LE 1280
Segments 1
Allocation inherit
Read ahead sectors auto
– currently set to 8192
Block device 253:2
— Logical volume —
LV Path /dev/hdd/data
LV Name data
VG Name hdd
LV UUID GwJgTL-LC8r-jn0a-yQ5H-mTX3-dARL-Xz0eOU
LV Write Access read/write
LV Creation host, time ,
LV Status available
# open 1
LV Size 4.00 GiB
Current LE 1024
Segments 1
Allocation inherit
Read ahead sectors auto
– currently set to 8192
Block device 253:3
I increased the LV on /dev/vg00/var by 100% (This is where the websites are stored). but this will quickly be used up once I continue to migrate more sites over!
This may also help. This is from running the mount command I have removed additional lines:
/dev/sda1 on / type ext3 (rw,noatime,data=ordered)
/dev/mapper/vg00-usr on /usr type ext4 (rw,noatime,data=ordered)
/dev/mapper/hdd-data on /data type ext4 (rw,noatime,quota,usrquota,data=ordered)
/dev/mapper/vg00-home on /home type ext4 (rw,noatime,quota,usrquota,data=ordered)
/dev/mapper/vg00-var on /var type ext4 (rw,noatime,quota,usrquota,data=ordered)
Thank you for your responses much appreciated!
which one of the following system that you cannot mount with the mount command ???
a) iso9660 b)swap c)FAT d)root e)VFAT