Singapore Yulon Vps Migration Guide Includes Detailed Explanation Of Data Backup And Dns Switching Steps

this article is an executable migration roadmap prepared for operators or webmasters using yulon vps in singapore, covering pre-migration checks, complete data backup solutions, file and database transfer techniques, dns switching and ttl scheduling, testing and rollback methods, with the goal of minimizing downtime and ensuring data integrity.

migration time depends on data volume, bandwidth and service complexity. synchronization of small sites (less than 10gb) through rsync or scp can usually be completed within a few hours; large sites (tens of gb to tb) need to plan snapshots, physical migrations or staged synchronization and reserve a 1-3 day window for testing. in terms of resources, it is recommended to temporarily increase the bandwidth and disk io performance of the target instance, prepare additional storage for intermediate backup, and arrange for a lead engineer and a backup support.

the choice of backup method should be based on data consistency and recovery speed. for the file level, rsync supports incremental transmission and resumed transmission, which is suitable for frequent synchronization; lvm snapshots or cloud disk snapshots are suitable for one-time migration of large data. in terms of database, mysql recommends using mysqldump (logical backup) or percona xtrabackup (physical cold backup) to ensure consistency; postgres uses pg_dump or basebackup. for databases with active transactions, a cold backup or lock point backup should be made first and the incremental log should be restored within a short maintenance window.

file backup: 1) execute rsync --archive --delete --compress --progress on the source host, first perform a full backup (it is recommended to go to the temporary target directory), and then perform at least one differential synchronization; 2) if using snapshots, first stop writing or briefly shut down, then create a snapshot and export it. database backup: 1) for mysql, execute mysqldump --single-transaction --routines --triggers -u root -p > dump.sql; 2) for postgresql, use pg_dump -fc; 3) if the amount of data is large, use physical backup tools and ensure that binlog or wal is copied after backup for incremental recovery. all backup files should be md5/sha256 verified and uploaded to the target or offline storage.

before migration, please conduct testing on the intranet or temporary subdomain (such as staging.example.com): 1) restore the backup on the target vps, start the service and perform a health check; 2) use the hosts file to point the domain name to the target ip, simulate real access and verify functions, performance and external interfaces (email, payment, third-party api); 3) conduct stress and load testing to check system bottlenecks. make sure monitoring and logging are configured correctly on the target for troubleshooting.

shortening dns ttl allows for faster switchovers and lower rollback costs. 24-48 hours before migration, lower the ttl of key domain names from the default (such as 3600-86400 seconds) to 300 seconds or less so that the dns records can take effect within a few minutes during the switch. restore the original ttl after the switch is completed and runs stably for 48-72 hours to reduce dns resolution load and caching problems.

switching steps: 1) confirm that the service is ready in the target environment and complete the last incremental synchronization; 2) pre-add the a/aaaa record of the target server in the dns provider but do not delete the old record immediately; 3) point domain name resolution to the target ip (or use cname in stages) during low traffic periods, and monitor the error rate; 4) use dig +trace, nslookup or online tools to check the resolution situation in various places; 5) update mx, spf, dkim, dmarc for mail services at the same time log and verify sends/receives. if problems occur, use hosts to force resolution or rollback dns to old records immediately.

rollback should be simple and executable: 1) keep the old server for at least 24-72 hours and keep data synchronized to the old machine; 2) prepare rollback scripts (restore dns to old values, restart old services, switch database master-slave roles); 3) record all changes (ip, ports, firewall rules, certificate paths) before switching; 4) once a serious failure is detected, immediately execute the rollback script and notify the user of the window time; 5) after rollback, perform complete data comparison and log analysis to find out the root cause and then try the migration again.

after the migration is completed and running stably, you should check: 1) whether the ssl/tls certificate is correctly bound and automatically renewed (let's encrypt); 2) whether the firewall and security group rules are minimized; 3) whether the backup and monitoring are switched to the target (backup runthrough, alarm threshold is reasonable); 4) log rotation and disk space policy; 5) whether the performance indicators (cpu, memory, iops, network) meet expectations, and adjust instance specifications or cache strategies if necessary.

pay attention to data encryption and access control during the migration process: 1) use ssh/sftp/rsync over ssh for transmission and disable password authentication, using keys and springboards; 2) encrypt backup files or place them in controlled storage; 3) record access and change logs, and comply with relevant compliance (for example, personal data needs to be processed according to regulations); 4) update credentials and api keys immediately on the target, and audit open ports to prevent exposure.