Answer:
(A) 1
Explanation:
In UNIX the file system the file system is a central part of the operating system. The file system is for storage and retrieval of information. Programs that form the UNIX system also stores information in files.
UNIX file systems supports three files namely: ordinary file, directory files, device files or special files.
If we need to access bytes 2500-2503 it means the bytes are within the third block. So we will need only one access.
Note this is because the file control block (inside) is within the memory. If file control block was not in the memory we would have needed more disk accessses.
Answer:
See attached file for detailed code.
Explanation:
See attached file.
Answer:
A tape drive provides sequential access storage, unlike a hard disk drive, which provides direct access storage. A disk drive can move to any position on the disk in a few milliseconds, but a tape drive must physically wind tape between reels to read any one particular piece of data.
Explanation:
Architecturally tape drives are sequential storage, meaning that if you need to access some data at the end of the tape you needed to seek to the end and retrieve it. This can take seconds or minutes. Disks, OTOH are random access. Some hard drives use rotating media and movable heads , so the seek times are instantaneous , at least compared with tape drives. However, like tapes, there is a big advantage to using a rotating hard drive as sequential storage. It takes time, measured in milliseconds, for a head to move to another track. So traditionally, random access is much slower than sequential access.
SSDs have no internal moving parts so random access occurs in the same time frame as sequential access. Moreover, these drives usually have very high performance. For example, they can saturate a SATA data link, meaning that the SATA connection to the motherboard is now a bottleneck in disk access.
At one time tape drives were very popular. They were a low-cost alternative to using disks as backup. They were especially useful when IBM invented the Winchester “fixed” drive. This meant that the hard drive is fixed within its enclosure like they are today. Prior to this one could remove the drive pack and replace it. This was helpful when upgrading to a new version of the operating system as it was simple to replace the older drive pack should there be a problem.
Tape drives can be used in larger data centers, due to the fact that tape volumes can be removed and replaced so that the actual tape drive can backup many disk sets. Also the tape volumes can be stored off-site or in a fire-proof vault so this is valuable in a data recovery scenario.
Answer:
A)
Explanation:
In this code example the missing piece of code would be...
public void setHourly(String isHourly)
This piece of code is creating a function called setHourly which takes in one String variable as it's parameter. Based on the rest of the code, the function takes that parameter variable and places it into an instance variable called Hourly which can be used when the function is called.
Answer:
to remind of purpose and use
Explanation:
When a data item has a meaningful name, the name can be a reminder of the purpose and use of the item. It can also be suggestive of the range of legitimate values. It also makes error-checking easier.
If the name of it is not meaningful, this information about the item must be found in a dictionary somewhere, often a time-consuming or difficult project. Using elements with non-meaningful IDs provides opportunities for error and confusion--not something that is generally wanted.
