Block Devices, Filesystems and Advanced Storage

A system administrator notices that a new 1TB NVMe drive (/dev/nvme0n1) is not detected by the kernel. The hardware is confirmed working. Which troubleshooting step should be taken first to check if the drive is recognized by the system's PCI subsystem?

An administrator is designing a high-availability storage solution using DRBD. The requirement is to have two nodes with synchronous replication and automatic failover in case of primary node failure. Which configuration best achieves this?

A filesystem is reported as 'read-only' after an unexpected power failure. Which command should be used to attempt repair without data loss?

Which TWO statements about LVM thin provisioning are correct?

A Linux administrator is managing a database server running on CentOS 7 that uses ext4 filesystems on LVM. The server has three physical volumes: /dev/sda (200GB), /dev/sdb (200GB), and /dev/sdc (200GB) all in volume group 'vg_db'. The logical volume 'lv_data' (400GB) is used for database files. Recently, the DBA reports that database writes are slower than expected. Iostat shows high average wait times (>100ms) on /dev/sdc but normal on /dev/sda and /dev/sdb. The LVM stripes data across all three PVs with a stripe size of 64KB. Which action should the administrator take to improve performance?

A system administrator needs to create a new 500 MB ext4 filesystem on /dev/sdb1 and mount it persistently at /data. Which set of commands accomplishes this task?

Which TWO statements about LVM thin provisioning are correct?

The administrator wants to create a RAID 1 array using /dev/sdb1 and /dev/sdc1, then create a filesystem and mount it at /mnt/raid1. Which command sequence should be used first?

Order the steps to configure a Linux system as a DHCP client using dhclient.

Arrange the steps to configure a Linux system as a PostgreSQL database server.

Match each LVM term to its definition.

Match each security tool to its function.

A Linux administrator notices that a newly added disk /dev/sdc is not recognized by the system. Which command should be used to rescan the SCSI bus without rebooting?

An administrator needs to create an ext4 filesystem on /dev/sdb1 with a block size of 4096 bytes and reserve 2% of blocks for root. Which command accomplishes this?

After adding a new LUN to an existing SAN, the administrator runs multipath -ll but sees the new LUN as 'failed'. The multipathd service is running. What is the most likely cause?

An administrator needs to extend an ext4 filesystem on logical volume 'home' by 5 GB. The volume group 'vg' has free extents. Which sequence of commands is correct?

A database server experiences performance degradation. Analysis shows high I/O wait on a LVM logical volume that uses striping across two physical volumes. What is the most effective way to improve performance?

A system's root filesystem on /dev/sda1 is offline. The administrator boots into rescue mode and needs to check the filesystem integrity. Which command should be used first?

An administrator creates a new XFS filesystem on /dev/vg/data and needs to mount it at /data with noatime and a stripe unit of 1 MiB. Which /etc/fstab entry is correct?

Which command can be used to display all UUIDs of block devices that contain filesystems?

A storage administrator sees the following output from multipath -ll: 'dm-3 (3600605b0038f1f0019f1f7e00000000) size=10G features='0' hwhandler='0' wp=rw' but the paths are all 'failed'. The scsi devices are listed in /proc/scsi/scsi. What is the most likely cause?

Which two commands can be used to create a swap space on a partition /dev/sdb2? (Choose two.)

Which two commands display information about LVM physical volumes? (Choose two.)

Which three conditions must be met for a filesystem to be mounted by UUID in /etc/fstab? (Choose three.)

Refer to the exhibit. The administrator wants to mount /dev/sdb1 at /data using its UUID. Which /etc/fstab entry is correct?

Refer to the exhibit. The /data filesystem is nearly full. The administrator has added a new disk /dev/sdc with 10GB capacity. The VG currently has no free space. Which steps will increase the available space for /data using LVM and ext4?

Refer to the exhibit. A system administrator wants to replace disk sdb1 in the RAID1 array. After physically removing sdb, which sequence of commands should be used?

A system administrator notices that a new iSCSI target is not appearing as a block device after running iscsiadm. The target is known to be online and reachable. What is the most likely cause?

Which command can be used to create a swap partition on /dev/sdb1?

An administrator wants to convert an ext4 filesystem to Btrfs without losing data. Which procedure should be used?

A filesystem check on an XFS filesystem reports corruption. What is the recommended way to repair it?

Which of the following is the primary configuration file for the udev device manager?

An administrator needs to configure iSCSI multipathing. After setting up two paths, which command should be used to verify the multipath topology?

A filesystem created with mkfs.ext4 on /dev/sda1 has a reserved block count of 5%. How can the administrator reduce it to 1% without reformatting?

Which file contains the filesystem table that is read during system boot to mount filesystems?

An administrator wants to create a thin provisioned LVM pool and a thin volume. Which sequence of commands is correct?

Which TWO commands display UUIDs of block devices? (Select TWO)

Which THREE of the following are correct statements about LVM thin provisioning? (Select THREE)

Which THREE of the following are correct about RAID 1 in mdadm? (Select THREE)

An administrator runs the command shown. However, when a user tries to execute a binary from /mnt/tmp, it fails with 'Permission denied'. What is the most likely cause?

An administrator observes that only one path is shown as active for mpathb. What is the most likely cause?

A company runs a database server on Linux with a 4-disk RAID 10 array using mdadm. The server recently experienced a power outage. After reboot, the array is not assembling automatically. The administrator runs `mdadm --assemble --scan` and it fails with a message: 'mdadm: /dev/md0 has been found but is not a valid md superblock.' The administrator checks /proc/mdstat and sees no arrays. The disks /dev/sda, /dev/sdb, /dev/sdc, /dev/sdd are present. Running `mdadm --examine /dev/sda` shows no md superblock, but the disk contains data partitions. The administrator suspects that the superblock may be corrupted or that the disks were accidentally overwritten. The administrator has documentation that the array was created with the following parameters: RAID level 10, 4 disks, chunk size 512 KiB, metadata 1.2. What is the best course of action to recover the array?

A server running Linux with an ext4 filesystem on /dev/sda1 has experienced an unexpected power loss due to a faulty power supply. After replacing the power supply and rebooting, the system fails to mount /dev/sda1 with an error message indicating 'wrong superblock magic number' or 'superblock corrupted'. The administrator recalls that ext4 filesystems have backup superblocks created during mkfs. Using the command 'dumpe2fs /dev/sda1 | grep -i backup' is not possible because the device is not mountable. However, the administrator remembers that for this specific filesystem, a backup superblock is located at block offset 32768 based on the output of 'mke2fs -n' from the original creation. What is the correct course of action to recover the filesystem and mount it?

An organization runs a critical application on a Linux server that stores its data on a 500GB LVM logical volume named /dev/vg_data/lv_app. The application must remain operational with minimal disruption, so unmounting the volume is not acceptable. The administrator needs to create a full backup of the logical volume to an external 1TB USB drive attached via eSATA. The backup must capture a point-in-time consistent state of the filesystem. The logical volume is formatted with XFS. Which of the following procedures best achieves this goal while minimizing downtime?

A system administrator needs to create a RAID 10 array using four disks: /dev/sdb, /dev/sdc, /dev/sdd, /dev/sde. Which TWO commands correctly achieve this?

An administrator wants to use /dev/sdb for a new ext4 filesystem. Which step must be performed first?

A database server uses LVM with an XFS filesystem on /dev/vg_data/lv_db, mounted at /var/lib/mysql. The LV is at 95% capacity. A new 50GB disk /dev/sdd has been added and initialized as a physical volume, then added to the volume group vg_data. The database is running and cannot be stopped. The administrator must extend the LV and filesystem. What is the correct course of action?