1. RoCE 1.1 Connectivity Requirements RDMA requires the same class of network end to end, for example the same /16 subnet. Single switch. RoCE: host NIC ── Ethernet switch (PFC) ── peer NIC Multiple switches. RoCE: host NIC ── Leaf ── Spine ── Leaf ── peer NIC When there are multiple hops, note:

1 Volatile Memory 1.1 REG REG (Register) is a storage unit inside the CPU, sitting right next to the arithmetic unit — the fastest and smallest level of the storage hierarchy. General-purpose registers (RAX/RBX/RDI on x86, and so on) take part directly in instruction execution, with access latency around 0.2–0.5 ns (roughly one clock cycle), lost on power loss, and typically only tens to hundreds of bytes.

1. Creating the Image File 1.1 When Loop Storage Fits Treat an ordinary file as a /dev/loopN block device: reads and writes go through the block device interface, while the backing file is still just a file on the host. Mounting ISO and disk images Local practice and stress testing

1. Viewing Package Dependencies 1.1 Forward Dependencies Which packages it depends on List dependencies 1 apt-cache depends apparmor 1 2 3 4 5 6 7 8 9 10 11 12 13 14 apparmor Depends: debconf # 必须 Depends: lsb-base # 必须 |Depends: debconf # 必须 Depends: <debconf-2.0>

This article covers single-node validation and three-node production deployment with cephadm. For architecture, operations, and functional testing, see Ceph Architecture and Operations. 1. Disk Preparation An OSD can only use a block device (/dev/sdX, a partition, /dev/loopN). 1.1 Inspecting Available Devices 1 2 3 4 5 6 7 lsblk -o