File Allocation Flashcards
What is a filing system?
It is like an index in the back of a book that tells the OS exactly where to find the file on the drive
How does an OS mark its files for the filing system?
If marks files so you know where they start and end, and where exactly they are stored or located
What is Binary?
a two digit counting system 0’s and 1’s, used by computers and networks
What is a “Bit”?
one binary digit, a 0 or a 1
What is a “Byte”?
a grouping of 8 bits
How many Bytes is 1 kilobyte?
1,000 Bits
How many Bytes is 1 Megabyte?
1,000,000 Bits
How many Bytes is 1Gigabyte?
1 Billion Bits
How many Bytes is 1 Terabyte?
1 Trillion Bits
What is Physical vs. Logical?
Physical is what you the user can see, Logical is what the Computer/Network can see
What are Sectors and Clusters?
Units of Storage, Indexing
What is a Sector?
512 Bytes, a Physical Representation on the drive, Physical divisions
What is a Cluster?
A Logical Concept done by the OS, clusters are decided by the OS, reducing the number of entries in our file index.
Standard is usually 8 Sectors per Cluster, or 4,096 Bytes
What are the 2 cardinal rules for Clusters?
1) All Clusters have to be the same size
2) They cannot be shared
What is File Fragmentation?
A File is fragmented when its clusters are not in consecutive order
**What does it mean to “Delete” a file?
You are telling the filing system that the spot the deleted file is in is now available, you just erase the entry in the index and wait for it to be overwritten by a new file that is stored in its place
**What is Slack Space?
the space between the end of the file and the end of the cluster
**When is data permanently gone?
When it is overwritten
Why choose larger clusters? Why not choose larger Clusters?
Advantages:
1) less chance for fragmentation
2) Speed
Disadvantages
1) less space on your HD for other files
2) a lot more slack space
