When making a system call from a guest OS process using trap-and-emulate virtualization, how many times does the VMM execute when making a system call to register a new timer interrupt (e.g., ask to be interrupted in 50ms)?

In NFS, when the server crashes and recovers, it has to contact all clients and tell them to re-open their files.

In p6, a user program wants to read the value of an xattr but does not know how large the value is. Which strategy does fgetxattr support for this?

Distributed systems and virtualization

The improved version of FFS tried to place directory data blocks near their corresponding inode.

When using virtual machines, what privileged state is accessed during a system call that requires a trap to the VMM?

A student submission runs a fork bomb (:(){ :|:& };:) inside a container, trying to spawn billions of processes. Which cgroup controller is most directly responsible for keeping the host alive?

What is the primary motivation for RAID-5 rotating parity across all disks, rather than keeping it on a single dedicated disk like RAID-4?

After a crash, a journaling file system performs recovery by scanning the journal. For each transaction it finds, what should recovery do?

In LFS, when a data block is written to disk, the inode that points to that data block is written to the same segment.