Which three statements are true concerning filesystems supported by Oracle Linux?
A.
An ext3 filesystem can be mounted as an ext2 filesystem.
B.
An ext4 filesystem can be mounted as an ext3 filesystem.
C.
The ext3 and ext4 filesystems both support multiple journaling modes.
D.
The btrfs filesystem includes a volume manager.
E.
The btrfs filesystem cannot be used for the root filesystem.
F.
The ext4 filesystem is a copy-on-write filesystem.
Explanation:
A: ext2 file systems are upgradeable to ext3 without reformatting.
C: The ext3 file system includes journaling capabilities to improve reliability and availability.
In addition to the features of ext3, the ext4 file system supports extents (contiguous physical
blocks), pre-allocation, delayed allocation, faster file system checking, more robust journaling, and
other enhancements.
Incorrect:
Not F: btrfs, not ext4, is a copy-on-write file system,
Starting with Oracle Linux 6 Update 3, the UEK Boot ISO (which boots the Unbreakable Enterprise Kernel
as the installation kernel) allows you to configure a btrfs root file system.
Integrated logical volume management allows you to implement RAID 0, RAID 1, or RAID 10
configurations, and to dynamically add and remove storage capacity
So anwser should be A,C,D
The btrfs file system provides the following important features:
Copy-on-write functionality allows you to create both readable and writable snapshots, and to roll back a file system to a previous state, even after you have converted it from an ext3 or ext4 file system.
Checksum functionality ensures data integrity.
Transparent compression saves disk space.
Transparent defragmentation improves performance.
Integrated logical volume management allows you to implement RAID 0, RAID 1, or RAID 10 configurations, and to dynamically add and remove storage capacity.
A, C, D:
A:
https://www.cyberciti.biz/faq/how-to-convert-back-linux-ext3-file-system-to-ext2-file-system/
C:
http://www.linuxplanet.com/linuxplanet/reports/4136/5
“the ext3 filesystem also offers several different types of journaling”
https://www.ibm.com/developerworks/library/l-anatomy-ext4/index.html
Ext4 supports multiple modes of journaling, depending upon the needs of the user. For example, ext4 supports a mode in which only metadata is journaled (Writeback mode), a mode in which metadata is journaled but data is written as the metadata is written from the journal (Ordered mode), and a mode in which both metadata and data are journaled (Journal mode—the most reliable mode). Note that Journal mode, although the best way to ensure a consistent file system, is also the slowest, because all data flows through the journal.
D: https://elpuig.xeill.net/Members/vcarceler/c1/didactica/apuntes/ud4/na3
“Btrfs El sistema de ficheros Btrfs incorpora la administración de volúmenes”