From Office Cloud to Self‑Hosted: A Case Study Migrating to Nextcloud + LibreOffice

Why we migrated: cost, control and predictable performance

Pain point: your organization pays recurring Microsoft 365 fees, worries about vendor lock-in, and needs tighter control over data residency — but you cannot sacrifice realtime co‑editing, search, and performance.

In this case study (2025–2026), I’ll walk through a real migration: a 250‑user engineering company moving from Microsoft 365/OneDrive to a self‑hosted stack composed of Nextcloud for file sync & sharing and LibreOffice Online (Collabora) for collaborative editing. You’ll get the technical steps, storage and SSD planning, cost analysis, performance benchmarks and adoption metrics — plus configuration examples and a migration checklist you can reuse.

Executive summary (most important first)

• Result: 78% of active users adopted Nextcloud within 6 months; avg document open time ~1.2s; concurrent editor support scaled to ~120 editors on a 3‑node Collabora pool.
• Cost: Annual software subscription savings of ~$60k (vs Microsoft 365), with a 14‑month break‑even when including hardware, hosting and staffing.
• Performance: Collabora worker avg CPU ~1.2 cores per editing session; NVMe SSDs with ZFS caching provided sub‑200ms file read latency for hot docs.
• Risk: Macro/complex Office features required a small percentage (<5%) of users to retain Office desktop apps; we preserved a read/write archival path for legacy files.

Context and 2026 trends that shaped our approach

In late 2025 and early 2026, organizations doubled down on self‑hosted alternatives for privacy, cost control and regulatory compliance. Two technical trends mattered for this migration:

• Collabora / LibreOffice Online maturity: Collabora’s CODE (and supported enterprise releases) improved multi‑user editing stability and memory use, reducing per‑user resource needs compared to 2022–2024.
• Storage hardware evolution: SSD supply chain dynamics (including advances reported by SK Hynix and peers) reduced some high‑end NVMe costs in late 2025, but emerging PLC/QLC models still require cautious procurement for write‑heavy workloads. We planned storage around TLC enterprise NVMe with ZFS to avoid endurance pitfalls; see our procurement notes and why refurbished devices & procurement choices matter for cloud security and predictable hardware lifecycles.

About the company and scope

Customer profile used in this case:

• 250 users (200 active), office + remote hybrid
• ~5 TB primary user data, 1 TB shared team data
• Typical day load: 200 active file accesses / minute; peak concurrency ~120 people editing documents
• Existing stack: Microsoft 365 E3, Azure AD SSO, OneDrive sync

Design decisions

Architecture

We selected a modular, horizontally scalable design:

• Nextcloud running behind Traefik for HTTPS / routing
• Collabora Online (CODE) in a scalable pool for document editing
• Redis for file locking and memcache
• MariaDB (Galera optional) for metadata
• ZFS on NVMe for primary storage with a warmed ARC + L2ARC strategy
• Monitoring: Prometheus + Grafana, alerting via PagerDuty

Authentication and SSO

We federated authentication to the existing Azure AD using SAML / OIDC (Nextcloud supports both). Key goals: maintain corporate SSO, reuse MFA, and avoid re‑issuing passwords.

Step‑by‑step migration plan

1. Audit and classify data, identify large vs legacy files.
2. Provision the Nextcloud stack (staging) and Collabora CODE test cluster.
3. Integrate SSO with Azure AD (SAML) and sync groups via LDAP or SCIM.
4. Bulk migrate files from OneDrive using rclone; validate checksums.
5. Gradual cutover — pilot team (25 users) → 3 departments → company wide.
6. Operationalize backups, monitoring and SLA runbooks.

Key CLI and config examples

Example rclone transfer (OneDrive → Nextcloud):

rclone copy "onedrive:/" "nextcloud:/Users/" --transfers=16 --checkers=8 --onedrive-chunk-size=64M --stats=1m --log-file=rclone-migrate.log

Nextcloud config.php highlights (important settings):

<?php
  $CONFIG = array (
    'trusted_domains' => array('cloud.example.com'),
    'datadirectory' => '/var/www/nextcloud/data',
    'memcache.local' => '\OC\Memcache\APCu',
    'memcache.locking' => '\OC\Memcache\Redis',
    'redis' => array('host' => '/var/run/redis/redis.sock','port' => 0),
    'filelocking.enabled' => true,
    'skeletondirectory' => '/usr/share/nextcloud/skeleton',
  );
  ?>

docker‑compose snippet for Collabora behind Traefik:

version: '3'
  services:
    collabora:
      image: collabora/code:latest
      environment:
        - domain=cloud.example.com
        - username=admin
        - password=secret
      ports:
        - "9980:9980"
      restart: always
      networks:
        - web
  networks:
    web:
      external: true
  

Storage planning and SSD selection

Storage is the foundation of user experience. We sized and tuned for small file IO, versioning and many concurrent reads/writes.

Sizing

• Primary user data: 6 TB gross (5 TB + 20% growth + versions)
• ZFS pool: 4x 4 TB NVMe drives in raidz1 for capacity + performance (replaceable with 6x for better redundancy)
• ARC memory: 48 GB RAM to keep metadata hot; add 1–2 TB L2ARC on separate NVMe for caching

SSD procurement (2026 considerations)

In early 2026 you’ll see cheaper high capacity drives but watch endurance: PLC/QLC may present lower write endurance and inconsistent perf for write‑heavy collaboration. We chose enterprise TLC NVMe drives (high DWPD) to keep predictable latency under sustained writes. SK Hynix and others introduced denser cells in 2025, but for critical VCS and document stores we prioritized endurance over headline capacity — read more on edge storage and tiering patterns for small SaaS deployments at Edge Storage for Small SaaS.

ZFS tuning

• Set dataset recordsize=16k–64k for small files (documents)
• Enable compression=lz4
• Separate ZIL (SLOG) on low‑latency NVMe for synchronous writes if heavy use of sync ops

Performance benchmarks

We executed load tests before and after production cutover. Tools: k6 (HTTP), internal Selenium scripts for collaborative editing flows, and server metrics via Prometheus.

Key results (typical)

• Document open time (Nextcloud + Collabora): median 1.2s, 95th perc 2.4s
• Initial document load CPU on Collabora: ~1.2 CPU cores per active editor session
• Save / write latency to ZFS (hot cache): median 150–220ms
• Sync throughput (rclone/initial migration): sustained 350 MB/s over VPN; reduced time by using parallel transfers

Scaling observations

Each Collabora CODE instance handled ~20–40 concurrent editors depending on document complexity. We used an autoscaling group for CODE in the cloud provider and a fixed 3‑node pool on‑prem for resilience; our autoscale and cloud‑burst playbook references platform ops patterns at Preparing Platform Ops for Hyper‑Local Pop‑Ups and Flash Drops. Scaling horizontally with smaller containers worked better than larger monolithic instances.

User adoption metrics and change management

Adoption is as much people work as technical work. We used a phased approach:

1. Pilot: 25 engineering power users for 2 weeks
2. Expand: add marketing and HR teams (additional 60 users)
3. Enterprise rollout: remainder in cohorts with training sessions

Measured outcomes at 6 months:

• Adoption: 78% of active users using Nextcloud as primary storage
• Support load: first 8 weeks had 1.9x tickets/week vs baseline; after 3 months tickets dropped below previous MS365 issues
• Collaboration: concurrent editing rose 120% vs baseline (measured as simultaneous live sessions), indicating users embraced the co‑editing workflows
• Fallback: <5% of users still required full desktop MS Office for macros/complex charts

Cost analysis

Simple comparison (annualized):

• Microsoft 365 E3 (250 users) ~ $20/user/month → $60,000/year
• Self‑hosted stack: initial hardware & setup CAPEX $10,500 + annual ops & hosting $12,000 → Year 1 about $22,500 (excl. staff salaries), plus support contracts for Nextcloud/Collabora if desired
• Break‑even: ~14 months including one‑time migration effort and modest enterprise support subscriptions

Note: replace numbers with your own procurement quotes; enterprise support subscriptions change the math but offer SLA and legal indemnities.

Security, backup and compliance

• End‑to‑end TLS, HSTS and strong ciphers via Traefik
• Server hardening, SELinux/AppArmor, and managed OS patching
• Backup strategy: ZFS snapshots hourly (retain 48 hours), daily replication to offsite object storage (S3 compatible), and monthly vault backups for compliance
• Audit logs: Nextcloud auditing app + central log ship to Elastic/Graylog for provenance and normalization

Common migration issues and fixes

• Large directories >100k files: migrate in chunks; use rclone with --fast-list disabled if memory limits are hit
• SSO group mapping: verify group names and case sensitivity; use SCIM where available to sync user attributes reliably
• Collabora encoding errors: ensure loolwsd and Nextcloud OAuth tokens are correctly configured and clock drift is minimal between servers
• Performance spikes: enable Redis locking and memcache, and monitor ZFS ARC hitrate — increase RAM if miss ratio grows

Monitoring and observability

We integrated these metrics:

• Nextcloud ideation: PHP‑FPM latency, Nextcloud cron duration, file locking counts
• Collabora: active sessions, worker CPU, memory, long‑requests tracking
• ZFS: ARC hit ratio, L2ARC usage, disk latency
• Network: outbound sync throughput and VPN tunnel health

Example Prometheus alert rule (high CPU on Collabora):

- alert: CollaboraHighCPU
    expr: avg by(instance) (rate(process_cpu_seconds_total{job="collabora"}[5m])) > 0.75
    for: 5m
    labels:
      severity: warning
    annotations:
      summary: "High CPU on Collabora instance {{ $labels.instance }}"
  

Lessons learned and recommendations

• Start small. Pilot with power users to catch edge cases early.
• Plan storage for endurance. Choose NVMe with sufficient DWPD; avoid QLC for write intense collaboration unless cost mandates.
• Tune Nextcloud. Use APCu, Redis, and offload large object storage to S3 when scalability is needed.
• Train and communicate. Adoption depends on documentation, champions and visible support SLA.
• Keep Office for macros. For a small group that needs macros, keep a licensed Office desktop and integrate it with Nextcloud as required.

"The migration reduced our SaaS exposure while improving control — but success required technical tuning and a people‑first rollout." — IT Lead, migrated company

Advanced strategies (2026 forward)

• Edge caching: deploy read caches in remote offices to reduce WAN round trips for large shared files — see Edge Storage for Small SaaS for edge tiering ideas.
• Autoscale Collabora: combine on‑prem and cloud burst for peak editing periods; platform ops patterns are useful when designing cloud bursts (platform ops playbook).
• Object storage tiering: keep hot docs on NVMe, cold archives on cheaper object storage (S3/MinIO).

Actionable migration checklist (copy & use)

1. Audit users, groups, storage usage and active file set.
2. Provision test Nextcloud + Collabora environment.
3. Integrate SSO (SAML/OIDC), test with pilot users.
4. Perform initial bulk migration with rclone; validate file integrity via checksums.
5. Configure caching (APCu/Redis), tune PHP‑FPM and increase RAM for ARC.
6. Run load tests (k6 + Selenium) to ensure Collabora capacity.
7. Train users, open a feedback channel and run weekly office hours for 6 weeks.
8. Cutover in cohorts and keep a rollback plan for 7 days.

Final verdict

This migration demonstrated that a medium‑sized company can successfully replace Microsoft 365 with Nextcloud + LibreOffice Online (Collabora) while maintaining realtime editing, strong performance and meaningful cost savings. The keys were deliberate storage planning, scaling Collabora horizontally, and a people‑led rollout.

Next steps & call to action

Want the migration checklist and configuration templates we used? Download the package (Nextcloud PHP config, rclone job file, Prometheus alerts, and a Collabora docker‑compose starter) and schedule a free 30‑minute migration review with our engineering team. If you’re considering hardware procurement, we’ll run an SSD endurance and ZFS sizing review aligned with 2026 hardware trends (see procurement and refurbished device guidance at keepsafe.cloud).

Get started: request the migration kit, or join the Nextcloud and Collabora communities for peer support — and if you need enterprise SLAs, evaluate paid support from Nextcloud GmbH and Collabora for production guarantees.

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