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mounting drives

Mounting Drives

# Take a look at the drives
lsblk
# Make this magical command work for you
sudo dd bs=4M if=input.iso of=/dev/sd<?> conv=fdatasync

Check drives on current machine

lsblk

Check file system type on current machine

ls -Th

https://www.tecmint.com/find-linux-filesystem-type/

Create, Mount, Unmount, and Use VFAT, EXT4 and XFS File Systems

  • Objectives:
    • Create MBR and GPT paritions
    • Put a file system on these paritions
    • Mount / unmount file systems
    • Delete these file systems and paritions

fdisk is for managing MBR partitions


fdisk xvdf

mkfs.vfat /dev/$WHATEVER

fsck.vfat

df -h

dump2fs /dev/$WHATEVER

blkid # Get UUID of block device

tune2fs -L LABEL_NAME /dev/$WHATEVER

mkfir.xfs -f /dev/$WHATEVER

mkdir /mnt/mount-location
mount /dev/$WHATEVER /mnt/mount-location
umount /mnt/mount-location

xfs_info /dev/$WHATEVER

xfs_repair /dev/$WHATEVER

gdisk /dev/$WHATEVER

## To delete a parition table
wipefs /dev/$WHATEVER

VFAT is for windows compatibility

What happens when I reboot

One can run out of i nodes and not be able to write

What is a LVM (logical volume manager)?

xfs, really fast and supports parallelization

/etc/fstab
/dev/WHATEVER /mnt/mount-location {file-system}} defaults 1 2

Mount and Unmount CIFS and NFS network file systems

# CIFS? Common Intenret File System
# Works with Windows and Linux
# Samba is an example of CIFS
# Next cert is where people learn how to create and manage these servers

sudo yum install samba-client cifs-utils nfs-utils

# In exam always mount persistently

smbclient -L {IP Address}}
mkdir -p /mnt/{sambashare, nfsshare} # Real Linux Command
mount -t cifs -o username={username}} //{IP Address}}/{Share Name}} {Mount Location}}
mount -t nfs {ip address}}:{Share}} {Mount Location}}
df -h

nano /etc/fstab
#samba
//{IP ADDRESS}}/{Share Name}}  {Mount Location}} cifs username={user}}, password={password}}
# NFS
{IP Address}}:/{Share Name}} {Mount Location}} nfs defaults 0 0

## reset mount from /etc/fstab
mount -a
``````

## Extend Existing Logical Volumes

``` bash

cd /dev
# Should see a bunch of aditional devices
fdisk /dev/{device}}
# Make sure to label device LVM
pvcreate /dev/{device}}
pvdisplay
vsgreate {name}} /dev/{device}}
lvcreate -n {new name}} -L {Size}G {name}}
mkfs -t xfs /dev/{name}}/{new name}}
mount /dev/{name}}/{new name}} {Mount Location}}
df -h
# With logical volumes you can add and remove phyiscal volumes without interupting the data on the volume
gdisk /dev/{new device}}
# Use linux LVM code
vsextend {name}} /dev/{new device}}

# Copy from one thing to another
pvmove /dev/{device}} # To remove data from

# Remove Phyiscal device
vgreduce {name}} /dev/{device}} # Device you want to remove

# Congradualtions you just did a live data migration

# Now to actually extend

lvextend -L {Size}}G /dev/{name}}/{new name}}  # Change size
lvextend -L +{Size}}G /dev/{name}}/{new name}} # Add
# Wait the file system is still fucked

xfs_growfs {Mount Point}}
# For ext4 resize2fs

lvextend -l +50%FREE /dev/{name}}/{new name}} # Take up 50% of aditional space

Create and Configure Set-GIT Directories for Collaboration

groups user
groups root

# Set-GID on directory and the permissions for new files created within will inheret
# UID? - User ID
# GID? - Group ID

mkdir {finance,it}
chmod g+s finance
groupadd finance
chown :finance finance
chmod g+wX -R finace
ls -al

Create and Manage Access Control Lists (ACLs)

    #Not supported by most file systems by default are XFS and EXT4
    # Use ACLs when you want more fine grande permission control than groups and users

    getfacl {file}}

    setfacl -m u:{username}}:{sembolic permissions such as example rw}}
    # ls -l, has plus to show ACL stuff active

    # chmod does not modify ACL, the mask can stop the ACL from doing what it wants

    # Why would group ID change

    # Default ACL

    setfacl -d -m u:{user}}:{Permissions}} directory # -d is for default
    setfacl --remove-default {directory}} # can also use -x

    # How to remove permissions for specifc users and groups for a firectory or file
    # -R for recursion
    # One can skip the user or group for a acl to set default permissions

Diagnose and Correct File Permission Problems