The xfs_info Command

• xfs_info designed for XFS

• XFS commands are used to create, modify, and manage XFS file systems. XFS is a journaling file system that supports large files and file systems on a single host.

• XFS

  • Journaling files system in Linux

  • Hierarchical structure

  • Efficiently manages disk space

  • Ensures data integrity

Advance Storage Management with Stratis

• RedHat8 introduces the next generation volume management solution called Stratis

• It used thin provisioning by default

• It combines the process of creating LVM and creation of filesystems into one management

• In LVM if a filesystem system gets full you will have to extend it manually whereas Stratis extends the filesystsem automatically if it has available space in its pool

1. Install Stratis package

   yum/dnf install stratis -cli stratisd

2. Enable and start

   systemctl start/enable stratisd

3. Add 2×5G new disks from virtualization software and verify at the OS level

   Oracle virtual box storage setting

   lsblk

4. Create a new stratis pool and verify

   stratis pool create pool1 /dev/sdb

   stratis pool list

5. Extend the pool

   stratis pool add-data pool1 /dev/sdb

   stratis pool list

6. Create a new filesystem using stratis

   stratis filesystem create pool1 fs1

   stratis filesystem list (Filesystem will start with 546MB)

7. Create a directory for mount point and mount filesystem

   mkdir /bigdata

   mount /stratis/pool1/ fs1 /bigdata

   lsb1k

8. Create a snapshot of your filesystem

   stratis filesystem snapshot pool1 fs1 fs1-snap

   stratis filesystem list

9. Add the entry to /etc/fstab to mount at boot

   UUID=”asf-0887afgdja-” /bigdata xfs defaults, x-systemd.requires=stratisd.service 0 0

RAID

• RAID (Redundant Array of Independent Disks)

• Types of RAID-

  1. RAID0

  2. RAID1

  3. RAID5

• RAID (Redundant Array of Independent Disks) in Linux is a storage technology that combines multiple disks into a single logical unit. This can increase performance, capacity, and data redundancy.

• How RAID works

  • RAID distributes data across multiple disks

  • RAID allows input/output (I/O) operations to overlap, which improves performance

  • RAID can use disk mirroring or disk striping

  • RAID arrays appear to the operating system as a single logical drive

File System Check (fsck and xfs_repair)

• Linux fsck utility is used to check and repair Linux filesystem (ext2, ext3, ext4, etc)

• Linux xfs_repair utility is used to check and repair Linux filesystems for xfs filesystem type

• Depending on when was the last time a file system, was checked, the system runs the fsck during boot time to check whether the filesystem is in consistent state.

• System administrator could also run it manulaliy when there is a problem with the filesystems

• Make sure to execute the fsck on an unmounted file systems to avoid any data corruption issues

• Force a filesystem check even if it’s clean using option -f

• Attempt to fix detected problems automatically using options -y

• The xfs_repair utility is highly scalable and is designed to repair even very large file systems with many inodes efficiently. Unlike other Linux file system, xfs_repiar does not run at boot time.

• The following are the possible exit codes for fsck command-

  | Code | Description | | --- | --- | | 0 | No errors. | | 1 | Filesystem errors corrected. | | 2 | The system should be rebooted. | | 4 | Filesystem errors were left uncorrected. | | 8 | Operational error. | | 16 | Usage or some type of syntax error. | | 32 | Checking canceled by the user through request. | | 128 | Shared-library error. |

System Backup

• Command » dd

• 5 Different Types of Backups

  1. System backup (entire image using tools such as acronis, Veeam, Commvault etc.)

  2. Application backup (3rd party application backup solution)

  3. Database backup (Oracle dataguard, SQL backup etc)

  4. Filesystem Backup (tar, gzip directories etc)

  5. Disk backup or disk cloning (dd command)

• dd is a command-line utility for Unix and Unix-like OS whose primary purpose is to convert and copy files

• As a result, dd can be used for tasks such as backing up the boot sector of a hard drive and obtaining a fixed amount of random data

• To backup or clone an entire hard disk to another hard disk connected to the same system, execute the dd command as shown-

  1. dd if= <source file name> of=<target file name> [options]

  2. dd if=/dev/sda of=/dev/sdb

• To backup/copy the disk partiotion

  1. dd if=/dev/sda1 of=/root/sda1.img

• Restoring this image file to other machine after copying the /img

  1. dd if=/root/sda1.img of=/dev/sdb3

Network File System (NFS)

• NFS stands for Network File System, a file system developed by Sun Microsystem, Inc.

• It is a client/server system that allows users to access files across a network and treat them as if they resided in a local file directory

• For example, if you were using a computer linked to a second computer via NFS, you could access files on the second computer as if they resided in a directory on the first computer. this is accomplished through the processes of exporting (the process by which an NFS server provides remote clients with access to its files) and mounting (the process by which client map NFS shared filesystem)

  

Steps for NFS Server Configuration

1. Install NFS packages

   # yum install nfs-utils libnfsidmap (most likely they are installed)

   

2. Once the packages are installed, enable and start NFS services

   # systemctl enable rpcbind

   # systemctl enable nfs-server

   # systemctl start rpcbind, nfs-server, rpc-statd, nfs-idmapd

   

   

   

3. Create NFS share directory and assign permissions

   # mkdir /mypretzels

   

   # chmod a+rwx /mypretzels

   

   

4. Modify /etc/exports file to add new shared filesystem

   # /mypretzels 192.168.12.7(rw,sync,no_root_squash) = for only 1 host

   # /mypretzels *(rw,sync,no_root_squash) = for everyone

   

5. Export the NFS filesystem

   # exportfs -rv

   

6. Stop and disable firewalld

   # systemctl stop firewalld

   # systemctl disable firewalld

   

Steps for NFS Client Configuration

1. Install NFS packages

   # yum install nfs-utils rpcbind

   

2. Once the packages are installed enable and start rpcbind service

   # systemctl rpcbind start

   

3. Make sure firewalld or iptables stopped (if running)

   # ps –ef | egrep “firewall|iptable”

   

4. Show mount from the NFS server

   # showmount -e 192.168.1.5 (NFS Server IP)

   

5. Create a mount point

   # mkdir /mnt/kramer

   

6. Mount the NFS filesystem

   # mount 192.168.1.5:/mypretzels /mnt/kramer

   

7. Verify mounted filesystem

   # df –h

   

   

   

   

8. To unmount

   # umount /mnt/kramer

   

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Thanks for going through this blog, Happy Learning !! 😁