To optimize performance, which of the following should be scheduled during low system load in LFS?

After a power failure, the LFS system appears to have lost recent file changes. Which component might not have updated in time?

You observe that your LFS file system is using disk space inefficiently. What is the likely cause?

Why does an LFS require more RAM compared to traditional file systems?

You design a system using LFS but experience high memory usage. What is a practical solution?

You need to reduce the garbage collection overhead in an LFS-based file system. Which approach would be most effective?

Distributed file systems store data across multiple nodes to ensure availability. Which system is an example?

In HDFS, data is divided into fixed-size blocks and distributed. What is the default block size?

Contiguous allocation stores files in consecutive blocks. What is the main drawback of this method?

Sequential allocation is best suited for which type of files?

Indexed allocation uses an index block to store pointers. What advantage does it have over sequential allocation?

Which type of allocation allows random access without external fragmentation?

Ceph uses an algorithm to distribute data evenly across disks. What is this algorithm called?

In a distributed computing environment, systems often need access to shared data. NFS allows multiple machines to access files from a common location. Identify the key benefit provided by NFS.

High-speed data access is crucial for real-time applications. Some storage technologies are designed for ultra-low latency. Select the technology optimized for fastest access.

Operating systems provide a consistent way for applications to interact with files, regardless of underlying storage types. This logical layer abstracts file operations. Identify this component.

Organizations using AWS need scalable, shared file storage across multiple instances. One service in AWS supports elastic file systems with POSIX compliance. Choose the correct AWS service.

Unix systems maintain metadata like ownership, timestamps, and access permissions in a special structure. This structure does not store file data directly. Identify the structure used.

When creating a file in Unix, the system must reserve a metadata structure for it. A specific system call handles this allocation. Choose the call responsible for inode reservation.

Cloud-based applications require scalable storage for images, logs, and unstructured data. Microsoft Azure provides an object storage solution optimized for this. Select the suitable service.

Disk scheduling manages order of disk I/O requests.

Block device drivers handle:

SCAN scheduling moves disk head:

The elevator algorithm in disk scheduling is also known as:

Character device drivers provide access to:

Device drivers act as an interface between:

AI-enhanced disk scheduling improves efficiency by:

Kernel-bypass I/O frameworks like io_uring use shared queues to manage multiple I/O requests without kernel switches. Which data structure manages these requests?

RDMA allows direct memory access between computers bypassing the OS. How does RDMA reduce CPU overhead?

DPDK achieves high throughput by avoiding kernel networking stack. Which technique does it use?

RDMA requires specific hardware for zero-copy transfers. Which hardware enables this?

DPDK processes packets in user space. How are packets received from NIC hardware?

RDMA uses certain transport protocols for data transfer. Which is commonly used?

Kernel-bypass I/O like io_uring reduces latency by minimizing what?

A system using LFS writes 5 small files in rapid succession. What performance benefit can be expected compared to a traditional file system?

An LFS writes a new version of a file every minute. Each version takes 4 KB. How many versions can fit in a 1 MB segment before the segment becomes full?

A flash-based embedded system uses LFS. You notice system slowdowns during heavy writes. What would be the most effective optimization?

If each inode is 128 bytes and you need to manage 10,000 files, how much space is needed for just the inodes in LFS?

An LFS has 10 segments with the following live data percentages: [90, 10, 20, 80, 40, 30, 15, 95, 60, 50]. Which segments should the cleaner target first to reclaim space efficiently?

You are evaluating LFS and ext4 for a mobile OS. The workload is 90% writes and runs on NAND flash. Which system offers better long-term performance and endurance?

In indexed allocation, what data structure is crucial for fast access to file blocks?

Analyze fragmentation: Which allocation type suffers the most from internal fragmentation?

What is the effect of replication factor in distributed file systems like Ceph and HDFS?

In distributed file systems, which layer typically handles client requests for file operations?

Evaluate the impact of contiguous allocation on file deletion and creation speed.

Ceph uses a distributed hash table. What is the primary purpose of this structure?

Which allocation method is most space-efficient for small files with random access?

Network file access can be achieved through several protocols. One major benefit of NFS compared to FTP is its design to maintain no client state. Identify this feature.

Operating systems may support different file systems like ext4, FAT32, or NTFS. One abstraction layer allows uniform access across them. Identify this layer.

Data-intensive applications such as machine learning benefit from a particular memory type that combines speed and persistence. Identify the suitable storage medium.

A fully managed service in Google Cloud Platform provides scalable file storage compatible with NFS. It is used with VMs and containers. Choose the correct service.

Buffer cache in Unix stores frequently accessed file blocks in memory to improve system performance.

Object storage manages data as discrete units with metadata. What key advantage does it have over block storage?

Driver buffering improves performance by:

The main limitation of SSTF is:

Which disk scheduling algorithm guarantees fairness by processing requests in arrival order?

Device drivers provide hardware abstraction by:

Block device drivers handle I/O in:

Batching I/O in io_uring affects syscall overhead by?

Which RDMA protocol supports lossless Ethernet?

Kernel bypassing in DPDK impacts security by requiring?

io_uring signals I/O completion through?

Hardware ensures RDMA transfers do not interfere with system by?

Binding NICs to DPDK drivers causes?

io_uring instance is created with which syscall?

A Log-Structured File System writes data in segments of 16 MB each. If a disk has a write bandwidth of 200 MB/s and the cleaning efficiency is 80%, how much time will it take to write 1 GB of new data including cleaning overhead?

If a file system using Copy-on-Write (CoW) has a disk bandwidth of 300 MB/s and snapshot creation takes 0.5 s, what is the maximum size of the snapshot data that can be created without impacting ongoing writes assuming writes take 3 seconds for 900 MB?

In an HDFS cluster with 5 data nodes, each with 4 TB storage, and a replication factor of 3, what is the effective usable storage?

A file system uses contiguous allocation on a disk of 1 TB with block size 4 KB. If a file is 100 MB, how many contiguous blocks does it occupy?

A disk with 1000 cylinders is at cylinder 200, and requests arrive for cylinders 100, 350, 600, and 900. Using SCAN (elevator) scheduling towards higher cylinders first, calculate total head movement.

An RDMA device transfers data at 10 Gbps. How many megabytes per second does this correspond to?

A Log-Structured File System segment size is 32 MB. Cleaning reclaims 70% of the segment. If writing a 1 GB file requires cleaning 5 segments, how much extra write overhead (in MB) does cleaning cause?

If a Btrfs snapshot copies 20% of a 500 MB file system, how much additional storage is needed?

A Ceph cluster uses replication factor 3 with 15 TB raw storage. What is the effective storage?

If a file system uses single-level index blocks of 4 KB, block pointers 4 bytes, how many data blocks can it point to?

Maximum File Size (Direct + Single Indirect + Double Indirect) Given: 12 direct blocks, 1 single indirect block, 1 double indirect block, block size 4 KB, pointer size 4 bytes. Calculate max file size.

Cache size 64 buffers of 4 KB. A 1 MB file is accessed repeatedly 5 times. How many cache hits after first read?

NVMe device has 15 µs latency and throughput 350,000 IOPS. What is the max throughput in MB/s (block size 4 KB)?

Azure charges $0.0184 per GB per month. Using 750 GB for 4 months, what's the cost?

Google Filestore reports 10,000 IOPS on a 1 TB instance. If block size is 8 KB, what is throughput in MB/s?

Using FCFS, Requests at cylinders: 45, 180, 10, 90, current at 50, calculate total head movement.

Using SSTF, Requests at cylinders: 45, 180, 10, 90, current at 50, calculate total head movement.

If AI reduces average seek time by 20% from 8 ms to what?

Block device with block size 512 bytes does 1000 IOPS, throughput?

Character device transmits 115,200 baud with 8 data bits, 1 stop bit, no parity. Effective data rate in bytes per second?

If io_uring reduces latency by 30% from 50 µs, what is new latency?

10 Gbps link with 80% utilization, effective bandwidth MB/s?

If ialloc takes 0.2 ms and ifree 0.1 ms, time for 500 allocations and 300 frees?

If NFS adds 5 ms latency per operation and local FS latency is 1 ms, total for 100 ops?

Persistent memory write bandwidth 3 GB/s, file size 600 MB, write time?

Disk with queue depth 32 and avg service time 10 ms, max IOPS?

AWS EFS throughput 100 MB/s per TB, with 3 TB used, throughput?

If disk I/O wait is 5 ms and CPU runs at 2 GHz with 1 instruction per cycle, how many instructions lost during wait?

Doubling block size from 4 KB to 8 KB decreases number of blocks by?

If DPDK transfers 8 million packets/sec at avg packet size 512 bytes, throughput?

A Unix file system allocates 1 inode per 4 KB. If a disk has 40 GB usable space, how many inodes can be created?

A file uses 10 direct blocks, 1 single indirect block (holds 256 addresses), and 1 double indirect ( $$256^2$$ ). What is max file size with 4 KB blocks?

A disk request queue is optimized by AI-based scheduling, reducing average seek time from 9 ms to 4 ms. If 5000 operations are processed, how much time is saved?

Azure Blob storage charges $$0.02 per GB/month and$$ 0.05 per 1000 transactions. You store 500 GB and perform 100,000 operations/month. What's total cost?