Storage.md

Storage.md

20% of Exam

• Configure and manage LVM storage
• Manage and configure the virtual file system
• Create, manage, and troubleshoot filesystems
• Use remote filesystems and network block devices
• Configure and manage swap space
• Configure filesystem automounters
• Monitor storage performance

Section 1

show commands

lsblk
sudo mkswap /dev/sdb
df -TH 
swapon -h
swapon -s
10MB 21MB 15MB
sudo fdisk /dev/vdb
# m for menu
m
# n for new partition 
n
# enter defaults and +10M for size 
+10M
# w for writing the partition
w
mkswap /dev/vdb2
swapon /dev/vdb2
swapon -s
swapoff /dev/vdb2
cfdisk

Summary

• List block devices: lsblk

  • Display information about all block devices on the system.

• Create a swap area on /dev/sdb: sudo mkswap /dev/sdb

  • Initialize the partition /dev/sdb as swap space.

• Check file system disk usage: df -TH

  • Show disk usage information for all mounted filesystems, with sizes in human-readable format and file system type.

• Display active swap space: swapon -h

  • Show the currently active swap spaces in a human-readable format.

• View detailed swap space information: swapon -s

  • Display detailed information about all swap spaces.

• Open fdisk to partition /dev/vdb: sudo fdisk /dev/vdb

  • Open fdisk to manage partitions on /dev/vdb.

• Use m for the help menu in fdisk: m

  • Display the help menu in fdisk.

• Create a new partition in fdisk: n

  • Create a new partition.

• Enter default values for the partition size and set it to +10M: +10M

  • Set the size of the new partition to 10MB.

• Write partition changes: w

  • Write changes and exit fdisk.

• Create a swap space on the new partition /dev/vdb2: mkswap /dev/vdb2

  • Initialize /dev/vdb2 as swap space.

• Enable the new swap space: swapon /dev/vdb2

  • Activate the swap space on /dev/vdb2.

• View swap space status: swapon -s

  • Display the status of active swap spaces.

• Disable a swap space: swapoff /dev/vdb2

  • Disable the swap space on /dev/vdb2.

• Open the cfdisk partition manager: cfdisk

  • Start the cfdisk utility to manage disk partitions with a graphical interface.

Section 2

show commands

mkfs.xfs -L "DataDisk" /dev/vdb
mkfs.ext4 -N 2048 /dev/vdc
mount /dev/vdb/ /mnt
mount /dev/vdb/ /mnt/
lsblk
mount /dev/vdb /mnt/
umount /mnt
mkdir /test
sudo mano /etc/fstab
cat /etc/fstab
sudo nano /etc/fstab


# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda1 during curtin installation
/dev/disk/by-uuid/8ee8caa8-cef0-4e5c-a626-03f2a0f13c00 / ext4 defaults 0 1
/swap.img       none    swap    sw      0       0
#VAGRANT-BEGIN
# The contents below are automatically generated by Vagrant. Do not modify.
#VAGRANT-END
/dev/vdc /test ext4 defaults 0 2
/dev/vdb none swap defaults 0 0

xfs_admin -L "SwapFS" /dev/vdb

Summary

• Format a disk with XFS and label it: mkfs.xfs -L "DataDisk" /dev/vdb

  • Format /dev/vdb with the XFS file system and label it "DataDisk."

• Format a disk with ext4 and specify the number of inodes: mkfs.ext4 -N 2048 /dev/vdc

  • Format /dev/vdc with the ext4 file system and create 2048 inodes.

• Mount a disk to a directory: mount /dev/vdb /mnt

  • Mount the /dev/vdb device to the /mnt directory.

• List block devices and their mount points: lsblk

  • Display information about block devices and their mount points.

• Unmount a device: umount /mnt

  • Unmount the device mounted at /mnt.

• Create a new directory: mkdir /test

  • Create the directory /test.

• Edit the /etc/fstab file with nano: sudo nano /etc/fstab

  • Open the /etc/fstab file in the nano text editor to manage filesystem mounts.

• View the contents of /etc/fstab: cat /etc/fstab

  • Display the contents of the /etc/fstab file.

• Example entry for /etc/fstab:

  <file system> <mount point>   <type>  <options>       <dump>  <pass>
  /dev/disk/by-uuid/8ee8caa8-cef0-4e5c-a626-03f2a0f13c00 / ext4 defaults 0 1
  /swap.img       none    swap    sw      0       0
  /dev/vdc /test ext4 defaults 0 2
  /dev/vdb none swap defaults 0 0

• Change the label of an XFS file system: xfs_admin -L "SwapFS" /dev/vdb

  • Change the label of the XFS file system on /dev/vdb to "SwapFS."

Section 3

show commands

cat /proc/mounts
findmnt
findmnt /dev/vda1
umount /mnt
mount /dev/vdb1 /mnt/ -o ro,noexec,nosuid
mount -o remount,rw /dev/vdb1 /mnt
vi /etc/fstab
/dev/vdb1 /mnt ext4 defaults,ro 0 2

Summary

• View currently mounted file systems: cat /proc/mounts

  • Display information about all mounted file systems from /proc/mounts.

• Find mounted file systems: findmnt

  • Display a tree of mounted file systems.

• Find where a specific device is mounted: findmnt /dev/vda1

  • Display the mount point for /dev/vda1.

• Unmount a device: umount /mnt

  • Unmount the device mounted at /mnt.

• Mount a device with specific options: mount /dev/vdb1 /mnt/ -o ro,noexec,nosuid

  • Mount /dev/vdb1 to /mnt with read-only, no execution, and no SUID options.

• Remount a device as read-write: mount -o remount,rw /dev/vdb1 /mnt

  • Remount /dev/vdb1 as read-write on /mnt.

• Edit the /etc/fstab file: vi /etc/fstab

  • Open /etc/fstab for editing to manage filesystem mounts.

• Example /etc/fstab entry: /dev/vdb1 /mnt ext4 defaults,ro 0 2

  • Mount /dev/vdb1 to /mnt with the ext4 file system in read-only mode.

Section 4

show commands

vi /etc/exports
/home 10.0.0.0/24(ro)
sudo exportfs -r
systemctl restart nfs-server
grep "/home" /etc/exports
mount 127.0.0.1:/home /mnt
vi /etc/fstab
127.0.0.1:/home /mnt nfs defaults 0 0
vi /etc/exports
/home 192.0.0.0/24(ro) 127.0.0.10(rw,no_root_squash)
exportfs -r

Summary

• Edit the NFS exports file: vi /etc/exports

  • Open /etc/exports to configure NFS shared directories.

• Example NFS export entry: /home 10.0.0.0/24(ro)

  • Share /home as read-only for the 10.0.0.0/24 subnet.

• Apply NFS export changes: sudo exportfs -r

  • Re-export all directories in /etc/exports without restarting the NFS service.

• Restart the NFS server: systemctl restart nfs-server

  • Restart the NFS server to apply changes.

• Verify NFS export configuration for /home: grep "/home" /etc/exports

  • Search for /home in the /etc/exports file to verify export configurations.

• Mount an NFS share locally: mount 127.0.0.1:/home /mnt

  • Mount the NFS share from 127.0.0.1:/home to /mnt.

• Edit /etc/fstab to mount NFS share automatically: vi /etc/fstab

  • Open /etc/fstab to configure automatic mounting.

• Example NFS /etc/fstab entry: 127.0.0.1:/home /mnt nfs defaults 0 0

  • Automatically mount the NFS share from 127.0.0.1:/home to /mnt at boot.

• Add multiple NFS export rules: vi /etc/exports

  • Open /etc/exports to add multiple export rules.

• Example multi-host NFS export entry: /home 192.0.0.0/24(ro) 127.0.0.10(rw,no_root_squash)

  • Export /home as read-only for the 192.0.0.0/24 subnet and as read-write with no_root_squash for 127.0.0.10.

• Apply NFS export changes: exportfs -r

  • Re-export all configured directories without restarting the NFS service.

Section 5

show commands

sudo apt install lvm2 -y
sudo lvmdiskscan

pvcreate /dev/vdb /dev/vdc

pvs
vi /root/pvsize

pvremove /dev/vdc
vgcreate volume1 /dev/vdb
vgextend volume1 /dev/vdc
vgreduce volume1 /dev/vdc
vgs
lvcreate --size 0.5G --name smalldata volume1
lvresize --size 752M volume1/smalldata
mkfs.xfs /dev/volume1/smalldata
sudo lvremove volume1/smalldata

Summary

• Install LVM2: sudo apt install lvm2 -y

  • Install the LVM2 package for managing Logical Volume Management (LVM).

• Scan disks for LVM physical volumes: sudo lvmdiskscan

  • Scan the system for available physical disks for LVM.

• Create physical volumes: pvcreate /dev/vdb /dev/vdc

  • Initialize /dev/vdb and /dev/vdc as physical volumes for LVM.

• Display physical volumes: pvs

  • Show information about all physical volumes on the system.

• Open a file for editing: vi /root/pvsize

  • Open /root/pvsize for editing (e.g., to save size info).

• Remove a physical volume: pvremove /dev/vdc

  • Remove the LVM label from /dev/vdc and wipe the physical volume.

• Create a volume group: vgcreate volume1 /dev/vdb

  • Create a volume group named volume1 using /dev/vdb as the physical volume.

• Extend a volume group: vgextend volume1 /dev/vdc

  • Add /dev/vdc to the volume1 volume group.

• Reduce a volume group: vgreduce volume1 /dev/vdc

  • Remove /dev/vdc from the volume1 volume group.

• Display volume groups: vgs

  • Show information about all volume groups on the system.

• Create a logical volume: lvcreate --size 0.5G --name smalldata volume1

  • Create a logical volume named smalldata with a size of 0.5 GB in the volume1 group.

• Resize a logical volume: lvresize --size 752M volume1/smalldata

  • Resize the logical volume smalldata in volume1 to 752 MB.

• Format a logical volume with XFS: mkfs.xfs /dev/volume1/smalldata

  • Format the logical volume smalldata in volume1 with the XFS file system.

• Remove a logical volume: sudo lvremove volume1/smalldata

  • Remove the logical volume smalldata from the volume1 volume group.

Section 6

show commands

# https://www.redhat.com/sysadmin/linux-access-control-lists
raid1 mirrored
cat /proc/mdstat
getfacl archive
# https://www.alibabacloud.com/help/en/ecs/use-cases/create-a-raid-array-for-a-linux-instance#:~:text=Run%20the%20mdadm%20command%20to,based%20on%20your%20business%20requirements.&text=If%20you%20are%20prompted%20that,to%20install%20the%20mdadm%20tool.

sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/vd[bc]
lsblk

setfacl --modify user:john:rw specialfile
setfacl --remove user:john specialfile
setfacl --modify group:mail:rx specialfile
setfacl --recursive --modify user:john:rwx collection/

Summary

• Check RAID status: cat /proc/mdstat

  • Display the current status of RAID arrays and devices.

• View access control lists (ACLs) of a file: getfacl archive

  • Show the ACLs for the file archive.

• Create a RAID 1 (mirrored) array: sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/vd[bc]

  • Create a RAID 1 array using two devices (/dev/vdb and /dev/vdc) and name it /dev/md0.

• List block devices: lsblk

  • Display information about block devices in a tree format.

• Modify ACLs to give user john read and write permissions: setfacl --modify user:john:rw specialfile

  • Grant read and write permissions to the user john on the file specialfile.

• Remove ACLs for user john: setfacl --remove user:john specialfile

  • Remove ACL entries for the user john on specialfile.

• Modify ACLs to give the group mail read and execute permissions: setfacl --modify group:mail:rx specialfile

  • Grant read and execute permissions to the group mail on specialfile.

• Recursively modify ACLs to give user john read, write, and execute permissions: setfacl --recursive --modify user:john:rwx collection/

  • Recursively grant read, write, and execute permissions to the user john on the collection/ directory and its contents.