902 A+ Chapter 10 - File Systems and RAID
How does RAID 4 write the data?
RAID 4 writes the data in blocks and not striped
What is a a downside of using a layered file system?
It can decrease performence
How do a large number of disks affect the mean-time-to-failure(MTTF)?
It decreases it. More disks increases the chance for failure.
What is RAID 3 effective for?
It is very effective for large sequential data, such as satellite imagery and video
What does I/O control do?
It manages I/O devices at the I/O control layer
What does a disk device do with a file system?
It provides in-place rewrite and random access
What kind of code does RAID 2 use for error correction?
RAID 2 uses Hamming Code for error correction
What is a VFS?
- A VFS is software that forms an interface between an OS kernel and a more concrete file system
What are the 2 RAID principles?
- Strip: Data store on one disk in a continuous section - Stripe: Set of strips at the same location across multiple disks
What is one of the roles of the Logical file system?
-Manages metadata information - All file systems structure except the data itself -Directory management -Protection -Translates file name into file number, file handle, location by maintaining file control blocks (inodes Unix)
What is one of the roles of the file organization modules?
-Understands files, logical address and physical blocks - Translates logical block number to physical block number -Remember: logical number is something that maps to a physical location -Manages free space, disk allocation
What are the different types of file?
1. Byte Sequence 2. Record 3. Tree
Whats an advantage of RAID 0?
An increased performance, as it is possible to read files in parallel.
How is data written using RAID 5?
Data is written in blocks on to data disks. Parity is generated and rotated around the data disks
What is altered to change who is able to access a file?
File Attributes
What are files?
Files are a collection of related information defined by the creator
Whats an advantage of RAID 1
RAID 1 is simple to implement and an increase to performance due to being able to read from either disk
How does RAID 6 extend RAID 5?
RAID 6 extends RAID 5 by adding another parity block
What does 'RAID' stand for?
RAID stands for Redundant Array of Independent(inexpensive) Disks
What two ways can files be accessed?
Sequential Access or Random Access
