CHFI: Hard Disks & File Systems
Questions and Answers 100% Solved
Hard disk interfaces - ✔✔- ATA/PATA (IDE/EIDE)
Serial ATA (SATA)
SCSI
Serial Attached SCSI (SAS)
USBs
Fibre Channel
HDDs:
Tracks - ✔✔- concentric circles on platters
numbered for identification purposes
read-write is done by rolling headers from inner to outermost part of the disk
,track numbering starts at zero (0)
HDDs:
Sector - ✔✔- the smallest physical storage unit on the disk platter
almost always 512 bytes
the optimal method of storing a file on a disk is in a contiguous series
____________________________________
Contents of a sector:
ID info
(sector number and location that identify sectors on the disk; status info of the sectors)
Synchronization fields
(the drive controller drives the read process using these fields)
Data
ECC
(code that ensures integrity of the data)
,Gaps
(spaces used to provide time for the controller to continue the read process)
Bit vs. Nibble vs. Byte - ✔✔- Bit: binary digit
0 or 1
- Nibble:
4 bits
- Bytes:
8 bits
HDDs:
Sectors:
Advanced format - ✔✔new hard drives are 4KB advanced format sectors
removes redundant header areas, lying between un-merged sectors
efficiently uses storage space by merging 512-byte sectors into one single 4KB sector
, HDDs:
Clusters - ✔✔the smallest logical storage unit on a hard disk.
a set of track sectors.
discreet chunks of data.
(aka. allocation units)
SIZE:
size can be altered to optimize performance of OS and disk utilization
depends on size of disk partition and type of file system installed
larger cluster size (>1 sector) minimizes fragmentation problems, increases probability of
unused space in a cluster, reduces disk storage area, reduces the unused area on the disk
HDDs:
Clusters:
Slack space - ✔✔the area of a disk cluster b/n the end of the file and the end of the cluster
Questions and Answers 100% Solved
Hard disk interfaces - ✔✔- ATA/PATA (IDE/EIDE)
Serial ATA (SATA)
SCSI
Serial Attached SCSI (SAS)
USBs
Fibre Channel
HDDs:
Tracks - ✔✔- concentric circles on platters
numbered for identification purposes
read-write is done by rolling headers from inner to outermost part of the disk
,track numbering starts at zero (0)
HDDs:
Sector - ✔✔- the smallest physical storage unit on the disk platter
almost always 512 bytes
the optimal method of storing a file on a disk is in a contiguous series
____________________________________
Contents of a sector:
ID info
(sector number and location that identify sectors on the disk; status info of the sectors)
Synchronization fields
(the drive controller drives the read process using these fields)
Data
ECC
(code that ensures integrity of the data)
,Gaps
(spaces used to provide time for the controller to continue the read process)
Bit vs. Nibble vs. Byte - ✔✔- Bit: binary digit
0 or 1
- Nibble:
4 bits
- Bytes:
8 bits
HDDs:
Sectors:
Advanced format - ✔✔new hard drives are 4KB advanced format sectors
removes redundant header areas, lying between un-merged sectors
efficiently uses storage space by merging 512-byte sectors into one single 4KB sector
, HDDs:
Clusters - ✔✔the smallest logical storage unit on a hard disk.
a set of track sectors.
discreet chunks of data.
(aka. allocation units)
SIZE:
size can be altered to optimize performance of OS and disk utilization
depends on size of disk partition and type of file system installed
larger cluster size (>1 sector) minimizes fragmentation problems, increases probability of
unused space in a cluster, reduces disk storage area, reduces the unused area on the disk
HDDs:
Clusters:
Slack space - ✔✔the area of a disk cluster b/n the end of the file and the end of the cluster
