Linux with Operating System Concepts

Command
Meaning
pvchange, vgchange, lvchange
Change attributes of a physical volume, volume group, logical volume
pvck, vgck
Check physical volume, volume group
pvcreate, vgcreate, lvcreate
Create a new physical volume, volume group, logical volume
pvmove
Move the PEs of a physical volume
pvresize
Resize a partition
vgextend, lvextend
Add a physical volume to a volume group, extend the size of a 
logical volume
vgmerge
Merge two volume groups
vgreduce
Remove a physical volume from a volume group
lvreduce, lvremove, lvresize
Reduce the size of a logical volume, delete a logical volume, resize a 
logical volume

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The Linux File System
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415
point for our new partition. The file system being mounted will use a device name, for 
instance, we might issue the command
mount /dev/sda3 /home2
assuming that the physical device sda3 stores the partition for the /home2 file space.
If we want to use nondefault options when mounting a device, we will use 
-o 
option
. 
Mount options are varied. We discussed many of them earlier in this section (auto, noauto, 
sync, async, ro, rw, etc.). There are a large number of other options available. A thorough 
look at the mount man page will convince you that learning all that mount can do can be 
challenging!
In addition to the typical format for mount, we can issue mount with just one of the 
following options:
• -a—mount all partitions as specified in the /etc/fstab directory
• -l—list all mounted partitions
• -l -t 
type
—list all mounted partitions of the 
type
specified (e.g., ext4, nfs)
Although most partitions will be mounted at the time the Linux kernel is initialized, 
some partitions will need to be mounted later, or unmounted and remounted. For instance, 
adding an external storage device such as an external hard disk or a USB drive will require 
mounting. When done with the device, for safety’s sake, you would want to unmount it. 
Or, you may wish to make a particular partition inaccessible for some time, for instance, 
if you were going to move the physical device or perform a backup. The partition would be 
unmounted temporarily and then remounted.
And then you might want to mount a 
remote file system
. A remote file system is a device 
storing a file system that is made available by network. The remote file system might be 
stored on a file server shared among multiple computers. Alternatively, the remote file 
system might be some computer that you have access to over the Internet. In any event, 
mounting the file system is not very difficult.
Let us take as an example that the remote computer 
www.someserver.com
has a 
directory /
home/stuff
. We want to mount this directory under our own /
home/cool-
stuff
directory. To accomplish this, we must make sure that the service 
netfs
is run-
ning (see Chapter 11). We also must create the directory /
home/coolstuff
. Then we 
perform the mount operation.
mount www.someserver.com:/home/stuff /home/coolstuff
Notice that our mount command is very similar to the previous example, the only dif-
ference is that our device’s name is now of the form 
remote_name:remote_mount_
point
(as opposed to local_device_name).
Because we are manually mounting this file system, we would be best served by adding 
detail to the mount command that we might otherwise find in the /etc/fstab file. These 

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Linux with Operating System Concepts
details would include the file system type and options that specify how we will access the 
remote partition. To specify the type, use 
–t