Chapter 15. Managing Advanced Storage Flashcards
Explain this command
lvresize -r -l 75%VG /dev/vgdata/lvdata
This resizes the logical volume so that it will take 75% of the total disk space in the volume group.
Explain this command
lvresize -r -l +75%VG /dev/vgdata/lvdata
This tries to add 75% of the total size of the volume group to the logical volume.
Explain this command
lvresize -r -l +75%FREE /dev/vgdata/lvdata
This adds 75% of all free disk space to the logical volume.
Explain this command
lvresize -r -l 75%FREE /dev/vgdata/lvdata
This resizes the logical volume to a total size that equals 75% of the amount of free disk space.
Which of the following is not a standard component in an LVM setup?
a. Logical volume
b. File system
c. Volume group
d. Physical volume
B.
It is common to create a file system on top of a logical volume, but this is not a requirement. For instance, a logical volume can be used as a device that is presented as a disk device for a virtual machine.
Which of the following is not an LVM feature?
a. Volume resizing
b. Hot replacement of failing disk
c. Copy on write
d. Snapshots
C.
Copy on write is a feature that is offered by modern file systems, such as Btrfs. It copies the original blocks a file was using before creating a new file, which allows users to easily revert to a previous state of the file. Copy on write is not an LVM feature.
Which partition type do you need on a GPT partition to mark it with the LVM partition type?
a. 83
b. 8e
c. 8300
d. 8e00
D.
On a GPT disk, LVM partitions must be flagged with the partition type 8e00.
Which of the following commands shows correctly how to create a logical volume that uses 50% of available disk space in the volume group?
a. vgadd -n lvdata -l +50%FREE vgdata
b. lvcreate lvdata -l 50%FREE vgdata
c. lvcreate -n lvdata -l 50%FREE vgdata
d. lvadd -n lvdata -l 50% FREE /dev/vgdata
C.
The lvcreate command is used to create logical volumes. Use -n name to specify the name. The option -l 50%FREE will assign 50% of available disk space, and vgdata is the volume group it will be assigned from.
Which command shows an overview of available physical volumes? (Choose two.)
a. pvshow
b. pvdisplay
c. pvs
d. pvlist
B and C.
The pvdisplay command is used to show extensive information about physical volumes. The pvs command shows a summary of essential physical volume properties only.
Which statement about resizing LVM logical volumes is not true?
a. The Ext4 file system can be increased and decreased in size.
b. Use lvextend with the -r option to automatically resize the file system.
c. The XFS file system cannot be resized.
d. To increase the size of a logical volume, you need allocatable space in the volume group.
C.
You can increase the size of an XFS file system, but it cannot be decreased.
How much storage is used in a Stratis file system for metadata storage?
a. 527 MiB
b. 1 GiB
c. 4 MiB
d. 4 GiB
A.
To write metadata, each Stratis volume requires 527 MiB of storage.
Which of the following lines correctly shows how a Stratis file system should be mounted through /etc/fstab?
a. UUID=abcd /stratis xfs defaults 0 0
b. /dev/stratis/stratis1 /stratis xfs defaults,x-systemd.requires=stratis.service 0 0
c. UUID=abcd /stratis xfs defaults,x-systemd.requires=stratis.service 0 0
d. /dev/stratis/stratis1 /stratis xfs defaults 0 0
C.
You need to mount Stratis volumes using the UUID and not the device name. Also, the option x-systemd.requires=stratisd.service needs to be included to ensure that the stratisd.service is loaded before systemd tries to mount the Stratis volume.
Which of the following environments could benefit from using VDO? (Choose all that apply.)
a. Virtualization
b. Databases
c. Containers
d. Cloud storage
A, C, D.
Because of its data deduplication features, VDO is doing very well in environments where redundant data is written. This particularly applies to cloud storage, containers, and virtualization.
Which option should you use while formatting a VDO device with the XFS file system to ensure that empty blocks are not immediately discarded?
a. -k
b. -K
c. -d
d. -D
B.
The -K option is used with the mkfs.xfs command to ensure that empty data blocks are not discarded immediately.
