True/False.
An important difference between a hard link and a soft link
in a file system is
- Reference counts are kept for hard links but not for soft links.
- Reference counts are kept for soft links but not for hard links.
- Hard links are allowed to create cycles, but soft links are not.
- Soft links require much less disk space than hard links.
An advantage of the file allocation table file
structure over the linked file structure is
- The file allocation table solution uses much less disk space
than the linked structure.
- The linked structure uses much less disk space than the file
allocation table structure.
- The file allocation table method allows faster seeks in files.
- The linked allocation method allows faster seeks in files.
A Unix inode stores
- Only the name of a file.
- Only file allocation information about a file.
- Only access permission information about a file.
- Access permissions and file allocation information for a file,
as well as some other information.
Contiguous
allocation of files has some advantages and some disadvantages.
Which of the following is NOT a
disadvantage of contiguous allocation?
- Fragmentation of the disk free blocks.
- Slow seek time.
- Difficulty of adding new blocks to the end of a file.
- Difficulty of adding new blocks to the beginning of a file.
Clustering is
- Creating large logical disk blocks from collections of
contiguous physical disk blocks.
- Allocating directories close to one another.
- Allocating files close to one another.
- Moving the blocks of a file closer to one another on the disk.
An advantage of clustering for a file allocation table is
- The file allocation table can be made contiguous on the disk.
- The file allocation table is smaller.
- The file allocation table can probably fit in a single disk block.
- The file allocation table becomes entirely unnecessary.
When striping is used with a RAID disk array, reliability becomes a
problem. How is that problem compensated for?
- By doing striping with smaller chunks of data.
- By doing striping with larger chunks of data.
- By storing information redundantly.
- It can only be solved by using highly reliable disk drives.
To read or write a block on a disk, a process must
- acquire the disk resource for its private use.
- send a direct i/o request to the disk.
- first check that the disk is powered up and spinning.
- make a request of the disk manager.
A directory is a kind of file.
Which of the following is NOT a reason
for not providing a means for processes to directly read and write
directories the way ordinary files are read and written?
- Directory organization changes from one operating system to
another, so programs that do direct access to directories are
non-portable.
- Allowing a process to write a directory will allow the process
to replace any permission information that is stored in the
directory, and hence will reduce system security.
- Processes that write a directory might destroy the directory
structure, causing a large part of the file system to be lost.
- A process is usually not allowed to find out the names of the
files that are part of a directory.
First-come-first-serve disk scheduling suffers from
what problem?
- There tends to be a large amount of disk head motion that can
be reduced by using other scheduling algorithms.
- The algorithm is not fair to processes, and can cause some
processes to wait for a long time.
- The algorithm causes files to become fragmented.
- The algorithm is difficult to implement.
The shortest-seek-time-first disk scheduling
algorithm suffers from what problem?
- There tends to be a large amount of disk head motion that can
be reduced by using other scheduling algorithms.
- The algorithm is not fair to processes, and can cause some
processes to wait for a long time.
- The algorithm causes files to become fragmented.
- The algorithm is difficult to implement.
The TCP protocol is responsible (among other things) for
- Routing packets through the network.
- Reliable delivery of packets between directly connected machines.
- Reliable delivery of large (multi-packet) messages between machines that are not necessarily directly connected.
- Dealing with differences among operating system architectures.
The IP protocol is primarily concerned with
- Routing packets through the network.
- Reliable delivery of packets between directly connected machines.
- Reliable delivery of large (multi-packet) messages between machines that are not necessarily directly connected.
- Dealing with differences among operating system architectures.