Key Points Of Off-site Backup And Security Configuration In The Purchase Process Of Korean Cloud Servers

1.

overview: why you should pay attention to off-site backup and security when deploying cloud servers in south korea

- south korea (seoul, busan) is an important node in the asia-pacific, and access speed and compliance are its advantages.
- e-commerce, saas and media services often require low latency and high availability.
- single points of failure, hardware failures and regional network outages will cause business unavailability.
- off-site backup (same city/different city/cross-country) can ensure that rpo and rto goals are achieved.
- at the same time, it is necessary to cooperate with cdn and ddos protection to reduce bandwidth peaks and attack risks.

2.

pre-purchase preparation: key points in selecting computer room and basic configuration

- region selection: seoul (seo) is suitable for traffic from mainland china and japan and south korea, and busan is suitable for submarine optical cable node redundancy.
- bandwidth specifications: it is recommended that the minimum public network bandwidth starts at 10mbps, and 100mbps or 1gbps is optional for production.
- public ip and elastic ip: confirm whether fixed elastic ip and bgp export are supported.
-storage type: select ssd (nvme) for database, sata can be used for cold backup.
- sla and after-sales: confirm 99.95% sla, technical support work order response time and cross-region rapid migration capabilities.

3.

offsite backup strategy and rpo/rto settings

- define rpo (acceptable data loss time) and rto (recovery time), typical rpo=1 hour/rto=30 minutes.
- backup types: mirror snapshot, file-level incremental, object storage backup (cold backup).
- backup location: hot backup in the same city, real-time synchronization in remote locations (seoul↔busan), cross-border cold backup (south korea↔japan/singapore).
- frequency and window: database increment every 5~15 minutes, daily snapshot of files, comprehensive volume.
- bandwidth and cost evaluation: for example, 1tb daily increment needs to consider synchronization bandwidth and storage costs.

4.

backup implementation technology stack and sample commands

- commonly used tools: rsync+ssh, borg/restic (encryption and deduplication), lvm/btrfs snapshot.
- object storage: use naver cloud/aws s3/wasabi for cold backup and support life cycle policies.
- example: daily increment using rsync + cron: 0 */1 * * * rsync -az --delete -e "ssh -i /root/id_rsa" /var/www/ backup@backup.example:/data/.
- snapshot and rollback: lvm snapshot or btrfs send/receive is used for minute-level rpo.
- encryption and transmission: enable aes-256 encryption for backup data during transmission and storage, and enable transmission compression and verification.

5.

security configuration key points: host, network and access control

- ssh security: disable password login, only allow key login, turn off root direct connection, use non-standard ports instead and enable fail2ban.
- firewall: use nftables/iptables or cloud security group to open only necessary ports (80/443/ssh management port).
- intrusion prevention: deploy waf (web application firewall) to intercept sql injection and xss, combined with log monitoring.
- vulnerability management: automatic patch strategy and image replacement cycle, daily inspection of operating system and key middleware.
- minimum permissions: separate account permissions for database and application. domain name resolution can only be modified by authorized personnel.

6.

cdn and ddos defense practical points

- cdn role: cache static resources, reduce origin site bandwidth energy consumption and reduce latency (time to first byte reduced by 30~70%).
- recommended: use cloudflare/akamai/local cdn acceleration, and enable site-wide https and caching rules.
- ddos protection: combining cloud vendor protection and third-party cleaning, common cleaning bandwidth is 1gbps~10gbps; large traffic attacks can reach hundreds of gbps and require dedicated cleaning.
- traffic policy: set rate limits, geo-blocking and acls, enable verification codes and tokens on key interfaces.
- drills and monitoring: conduct regular fault drills and set alarm thresholds (for example, traffic >200mbps or concurrent connections >50k triggers an alarm).

7.

real cases and server configuration examples (including tables)

- case: a korean e-commerce company has a dual-active architecture. the main node in seoul handles user requests, and the backup node in busan performs remote synchronization.
- attack record: once encountered a 500mbps udp amplification attack, after enabling cloud vendor cleaning, it returned to normal within 10 minutes.
- taking the mid-year deployment as an example, the configuration is as shown in the following table and core commands and protection examples are given.
- core command example: iptables -a input -p tcp --dport 22 -m conntrack --ctstate new -j accept; brute force cracking is prohibited after fail2ban is enabled.
- recovery process: execute rsync from the backup server or pull a snapshot from the object storage and rebuild the service. the estimated rto is about 20 to 45 minutes.

node	cpu	memory	disk	public network bandwidth	backup strategy
master node (seoul)	8 vcpus	32gb	500gb nvme (raid1)	1 gbps	live asynchronous rsync + daily snapshots
backup node (busan)	4 vcpus	16 gb	2 tb sata (object cold standby)	200mbps	hourly increment, comprehensive volume, s3 remote cold backup