1.How
free-space is managed using bit vector implementation?
The free-space list is implemented as a
bit map or bit vector. Each block is represented by 1 bit. If the block is
free,the bit is 1; if the block is allocated, the bit is 0.
2.Define
buffering.
A buffer is a memory area that stores
data while they are transferred between two devices or between a device and an
application. Buffering is done for three reasons
a.
To
cope with a speed mismatch between the producer and consumer of a data stream
b. To
adapt between devices that have different data transfer sizes
c.
To
support copy semantics for application I/O
3.Define
caching.
A cache is a region of fast memory that holds copies
of data. Access to the cached copy is more efficient than access to the
original. Caching and buffering are distinct functions, but sometimes a region
of memory can be used for both purposes.
4.Define
spooling.
A spool is a buffer that holds output
for a device, such as printer, that cannot accept interleaved data streams.
When anapplication finishes printing, the spooling system queues the corresponding
spool file for output to the printer. The spooling system copies the queued
spool files to the printer one at a time.
5.What are the
various disk-scheduling algorithms?
The various disk-scheduling algorithms
are
a. First Come First
Served Scheduling
b. Shortest Seek
Time First Scheduling
c. SCAN Scheduling
d. C-SCAN
Scheduling
f. LOOK scheduling
