| You are a Ceph storage administrator. Deploy a Ceph cluster and configure block storage on the following infrastructure. | |
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| ENVIRONMENT | |
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| Nodes: node0 through node6 (7-node KVM cluster on a private libvirt network) | |
| You are currently on node0. From node0 you have passwordless root SSH to every | |
| other node by short name: | |
| ssh root@node1 ... ssh root@node6 | |
| `/etc/hosts` and `/etc/syscraft/cluster-info` are populated on every node with | |
| the mapping `<short-name>=<ip>`. Use those for any IP lookups. | |
| Network: | |
| Single private subnet 192.168.100.0/24 on the only NIC of each VM. | |
| Look up node0's private IP for `--mon-ip`: | |
| awk -F= '/^node0=/{print $2}' /etc/syscraft/cluster-info | |
| Do NOT pass `--cluster-network` — this deployment uses a single network. | |
| Storage: | |
| Each node has TWO unused raw block devices for OSDs: | |
| /dev/loop0 (~30 GiB) | |
| /dev/loop1 (~30 GiB) | |
| The root filesystem is on /dev/vda — do not touch it. | |
| The loop devices are attached automatically at boot by a systemd unit; if | |
| they are missing on a worker for any reason, `losetup -f --show | |
| /var/lib/cephbench/disk_b.img` (and `disk_c.img`) will recreate them. | |
| OS: Ubuntu 24.04 LTS on all nodes. | |
| Container runtime: podman is installed on all nodes. | |
| Pre-installed tooling (ready to use, no installation needed): | |
| cephadm (Ceph Squid, v19.x) — available on all nodes via /usr/sbin/cephadm | |
| podman, lvm2, xfsprogs, chrony, jq — installed on all nodes | |
| Pre-pulled image: quay.io/ceph/ceph:v19.2.0 (Ceph Squid) | |
| This image is already cached in podman on every node. | |
| `--image` is a GLOBAL flag that comes BEFORE the subcommand: | |
| cephadm --image quay.io/ceph/ceph:v19.2.0 bootstrap ... | |
| NOT: cephadm bootstrap --image ... (this will fail) | |
| Node hostnames may be FQDN-shaped. Pass `--allow-fqdn-hostname` to cephadm | |
| bootstrap. | |
| When adding hosts to the cluster, the short name must match the actual | |
| hostname on that node. The nodes' short names are `node0`..`node6`. | |
| Correct usage: `ceph orch host add node1 <node1-ip-from-cluster-info>` | |
| (short name first, then IP as the address) | |
| This is a 7-node cluster — do NOT pass `--single-host-defaults`. | |
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| TASKS (all must be completed) | |
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| 1. Bootstrap a Ceph cluster using cephadm on node0. | |
| 2. Join node1 through node6 into the cluster. | |
| 3. Add all available data disks (`/dev/loop0` and `/dev/loop1` on each node) | |
| as OSDs. | |
| 4. Create a replicated storage pool named "data_rep" with 3 replicas and | |
| application=rbd. | |
| 5. Create an erasure-coded storage pool named "data_ec" using: | |
| - Algorithm: reed_sol_van (jerasure plugin) | |
| - k=4, m=2 | |
| - Failure domain: host | |
| 6. In the data_rep pool, create a 100 GiB RBD block device image named | |
| "bench_image". Map it to a local block device on node0, format it with | |
| xfs, and mount it at /mnt/ceph_data. | |
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| SCORING | |
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| 5 pts — Ceph cluster is reachable (bootstrap succeeded) | |
| 15 pts — Cluster health is HEALTH_OK | |
| 15 pts — data_rep pool: 3 replicas, type=replicated, application=rbd | |
| 15 pts — data_ec pool: k=4 m=2 reed_sol_van jerasure host failure domain | |
| 20 pts — bench_image exists in data_rep, size ~100 GiB | |
| 20 pts — /mnt/ceph_data is mounted | |
| 10 pts — data can be written to /mnt/ceph_data | |