How many lookup calls are needed to resolve a 5-part pathname (for example, /usr/users/jim/code/
xyz.c) for a file that is stored on an NFS server? What is the reason for performing the translation
step-by-step?

What will be an ideal response?


Five lookups, one for each part of the name.
Here are several reasons why pathnames are looked up one part at a time, only the first of those listed is
mentioned in the book (on p. 229):
i) pathnames may cross mount points;
ii) pathnames may contain symbolic links;
iii)pathnames may contain ‘..’;
iv)the syntax of pathnames could be client-specific.
Case (i) requires reference to the client mount tables, and a change in the server to which subsequent lookups
are dispatched. Case (ii) cannot be determined by the client. Case (iii) requires a check in the client against the
‘pseudo-root’ of the client process making the request to make sure that the path doesn’t go above the pseudo
root. Case (iv) requires parsing of the name at the client (not in itself a bar to multi-part lookups, since the
parsed name could be passed to the server, but the NFSD protocol doesn’t provide for that).

Computer Science & Information Technology

You might also like to view...

User applications run in ______ which is the least trusted area.

A) Ring 0 B) Ring 1 C) Ring 2 D) Ring 3

Computer Science & Information Technology

The Common name field on the certificate request is usually the FQDN of the portal.

Answer the following statement true (T) or false (F)

Computer Science & Information Technology

In ________ encryption, a key pair is created, where one key is for coding and the other is for decoding

Fill in the blank(s) with correct word

Computer Science & Information Technology

You can specify where you want to store a database when you create it

Indicate whether the statement is true or false

Computer Science & Information Technology