Linux: Difference between revisions
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! Command | ! Command | ||
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| style="width: 50%;" | Create a volume group. | | style="width: 50%;" class="cli" | Create a volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgcreate vg1 /dev/sdb1 /dev/sdc1 | ||
|- | |- | ||
| style="width: 50%;" | Add a physical volume to a volume group. | | style="width: 50%;" class="cli" | Add a physical volume to a volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgextend vg1 /dev/sdd1 | ||
|- | |- | ||
| style="width: 50%;" | Display volume group. | | style="width: 50%;" class="cli" | Display volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgdisplay new_vg | ||
|- | |- | ||
| style="width: 50%;" | Scan disks for volume groups. | | style="width: 50%;" | Scan disks for volume groups. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgscan | ||
|- | |- | ||
| style="width: 50%;" | Remove a physical volume from a volume group. | | style="width: 50%;" | Remove a physical volume from a volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgreduce group_name /dev/sdc1 | ||
|- | |- | ||
| style="width: 50%;" | Change the maximum number of logical volumes of volume group vg00 to 128. | | style="width: 50%;" | Change the maximum number of logical volumes of volume group vg00 to 128. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgchange -l 128 /dev/vg00 | ||
|- | |- | ||
| style="width: 50%;" | Activate or deactivate a volume group. | | style="width: 50%;" | Activate or deactivate a volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgchange -a n my_volume_group | ||
|- | |- | ||
| style="width: 50%;" | Remove a volume group. | | style="width: 50%;" | Remove a volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgremove officevg | ||
|- | |- | ||
| style="width: 50%;" | Split the physical volumes of a volume group and create a new volume group. | | style="width: 50%;" | Split the physical volumes of a volume group and create a new volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | $ vgsplit bigvg smallvg /dev/ram15<br>Volume group "smallvg" successfully split from "bigvg" | ||
|- | |- | ||
| style="width: 50%;" | Merge the inactive volume group my_vg into the active or inactive volume group databases giving verbose runtime information. | | style="width: 50%;" | Merge the inactive volume group my_vg into the active or inactive volume group databases giving verbose runtime information. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgmerge -v databases my_vg | ||
|- | |- | ||
| style="width: 50%;" | Change the name of a volume group. | | style="width: 50%;" | Change the name of a volume group. | ||
| style="width: 50%;" | | | style="width: 50%;" class="cli" | vgrename vg02 my_volume_group | ||
|} | |} | ||
Revision as of 05:57, 3 April 2018
SSH
| Description | Command |
|---|---|
| Create private/public SSH key file using 2048 bit encryption and with a comment. The command creates files under ~/.ssh folder. | ssh-keygen -b 2048 -C user@host.domain
|
| Push public SSH key to a server | ssh-copy-id -p 41111 -i ~/.ssh/id_rsa.pub mhan@remote.server.com
|
| Reset (SELinux) permissions related to SSH. This may be needed if all else fails to correct the issue of system not accepting public keys. | restorecon -R -v ~/.ssh
|
Disk
LVM
Physical volume
| Description | Command |
|---|---|
| Initialize for use as LVM physical volume. | pvcreate /dev/sdb1
|
| Scanning for block devices. | lvmdiskscan
|
| Display the physical volumes. | pvdisplay
|
| Show all physical devices. | pvscan
|
| Prevent allocation of physical extents on the free space of one or more physical volumes. | pvchange -x n /dev/sdb1
|
| Resize. | pvresize
|
| Remove LVM label. | pvremove
|
Volume group
| Description | Command |
|---|---|
| Create a volume group. | vgcreate vg1 /dev/sdb1 /dev/sdc1 |
| Add a physical volume to a volume group. | vgextend vg1 /dev/sdd1 |
| Display volume group. | vgdisplay new_vg |
| Scan disks for volume groups. | vgscan |
| Remove a physical volume from a volume group. | vgreduce group_name /dev/sdc1 |
| Change the maximum number of logical volumes of volume group vg00 to 128. | vgchange -l 128 /dev/vg00 |
| Activate or deactivate a volume group. | vgchange -a n my_volume_group |
| Remove a volume group. | vgremove officevg |
| Split the physical volumes of a volume group and create a new volume group. | $ vgsplit bigvg smallvg /dev/ram15 Volume group "smallvg" successfully split from "bigvg" |
| Merge the inactive volume group my_vg into the active or inactive volume group databases giving verbose runtime information. | vgmerge -v databases my_vg |
| Change the name of a volume group. | vgrename vg02 my_volume_group |
Users
UID or GID
| Description | Command |
|---|---|
| Check UID. | id -u username |
| Check GID. | id -g username |
| Check all of the groups a user belongs to. | id -G username |
| Check UID and all of the groups a user belongs to. | id username |
File
Permissions
| Letter | Number |
|---|---|
| r | 4 |
| w | 2 |
| x | 1 |
| rw- | 6 |
| r-x | 5 |
| rwx | 7 |