Mounting Remote File Systems

What is required when mounting a remote file system?

The OS must handle differences in:

• Data representation

• File naming conventions

• Directory structures
  ...by using established rules/protocols for information exchange.

How are remote file system access rules typically established?

• Often de facto standards set by platform vendors.

• Sometimes become open standards (e.g., NFS).

• Other vendors may reverse-engineer access protocols.

How does Windows represent remote file systems?

As drive letters (e.g., Z:), using unused letters for remote resources.

How does UNIX represent remote file systems?

As nodes in the file system tree, replacing or adding a directory with a remote resource marker.

What is a key advantage of remote mounting for programmers?

Programs can access remote files transparently, without code modifications.

What is a potential downside of remote file access for programs?

Performance issues (e.g., database operations over WANs) due to high network traffic.

What is a better alternative for remote database access?

Run the database remotely and send only SQL queries/results over the network.

What problem arises with pathname parsing in remote file systems?

Each "/" in a path (e.g., /fred/work/expenses) may point to a local directory or remote file system, requiring checks at every level.

How can mounting the same remote directory at different local paths cause issues?

• Windows: Users may assign different drive letters (e.g., X: vs. Y:).

• UNIX: Users may mount at different tree nodes (e.g., /mnt/data vs. /home/data).
  This breaks pathname sharing between users.

How can administrators standardize remote mounts?

Use login-time scripts to ensure consistent mount points for shared resources.