As a Linux-friendly hosting panel, Plesk uses log files for a wide range of software packages that run under Linux in addition to its own logs. Below, we’ve compiled a list detailing the locations of Plesk logs. And we hope it helps you fix issues.Plesk SystemError log: /var/log/sw-cp-server/error_log and /var/log/sw-cp-server/sw-engine.logThese logs capture error messages and other relevant information related to the operation of the SW-CP-Server, which is responsible for managing the Plesk control panel interface and various administrative tasks within Plesk. Monitoring these logs can provide valuable insights into any issues or errors occurring within the SW-CP-Server service, helping sysadmins diagnose and troubleshoot problems effectively.Access log: /usr/local/psa/admin/logs/httpsd_access_logSpecifically, this log captures information about HTTP requests made to the Plesk control panel, including details such as the IP address of the client making the request, the requested URL, the HTTP status code returned by the server, and other relevant information. Monitoring this access log can provide valuable insights into who is accessing the Plesk control panel and what actions they are performing, which can be useful for security monitoring, troubleshooting, and performance optimization purposes.Panel log: /usr/local/psa/admin/logs/panel.logThis log captures various events and activities related to the Plesk control panel’s operation and administration. It includes information about user logins, administrative actions, system events, errors, warnings, and other relevant details. Monitoring the panel log is essential for sysadmins to track changes made to the Plesk environment, diagnose issues, troubleshoot errors, and ensure the smooth functioning of the control panel.Plesk Installer/var/log/plesk/installer/autoinstaller3.logThe “/var/log/plesk/installer/autoinstaller3.log” file is part of Plesk’s installation and update logging system. This log captures detailed information about the installation and update processes performed by the Plesk Installer tool, including the installation or update of Plesk components, third-party software, and system packages. Monitoring this log is essential for sysadmins to track the progress of Plesk installations and updates, diagnose installation failures or errors, and troubleshoot any issues that may arise during the installation or update process.Similar to “/var/log/plesk/installer/autoinstaller3.log”, this log also captures detailed information about the installation and update processes performed by the Plesk Installer tool. However, it is stored in the temporary directory (“/tmp/”) and may contain temporary logs or data generated during the installation or update process. Monitoring this log can provide additional insights into the installation and update activities, complementing the information available in other Plesk logs.Web Presence BuilderError log: /usr/local/psa/admin/logs/sitebuilder.logThe “Error log” at “/usr/local/psa/admin/logs/sitebuilder.log” records issues and relevant data related to Plesk’s Web Presence Builder feature. It’s essential for sysadmins to troubleshoot any errors users encounter when creating or editing websites in Plesk.Install/upgrade logs: /usr/local/sb/tmp/The “Install/upgrade logs” directory at “/usr/local/sb/tmp/” stores logs related to installations and upgrades within Plesk’s Web Presence Builder feature.Backup ManagerBackup logs: /usr/local/psa/PMM/logs/backup-<datetime>The “Backup logs” directory at “/usr/local/psa/PMM/logs/backup-<datetime>” contains logs specific to the backup process managed by Plesk’s Backup Manager.Restore log: /usr/local/psa/PMM/logs/restore-<datetime>The “Restore log” directory at “/usr/local/psa/PMM/logs/restore-<datetime>” stores logs related to the restoration process managed by Plesk’s Backup Manager.Plesk Migrator/usr/local/psa/var/modules/panel-migrator/logs/The “Plesk Migrator” directory at “/usr/local/psa/var/modules/panel-migrator/logs/” is used to store logs related to migration processes facilitated by Plesk’s Migration Manager. These logs contain detailed information about the migration of websites, databases, email accounts, and other data from one server to another. They help administrators track the progress of migration tasks, diagnose any errors or issues encountered during the migration process, and ensure a smooth transition of data between servers.Migration ManagerThese logs document various aspects of the migration, including the source and destination servers, migrated data types (such as websites, databases, email accounts), and any errors or warnings encountered during the migration process./usr/local/psa/PMM/logs/migration-<datetime>Website ImportThese logs record details such as the source of the imported website, the progress of the import process, and any errors encountered during the import operation./usr/local/psa/var/modules/site-import/sessions/Health Monitor ManagerHealth Monitor Manager logs contain information about the health status and performance metrics of servers managed by Plesk’s Health Monitor Manager service. These logs record system alerts, resource usage statistics, and any anomalies detected during health checks./usr/local/psa/admin/logs/health-alarm.logHealth Monitor Notification DaemonThese logs detail alerts related to server health, resource usage, and any abnormalities detected during monitoring./usr/local/psa/admin/logs/health-alarm.logFTPThese logs record details such as user login attempts, file uploads, downloads, and any errors encountered during FTP sessions./usr/local/psa/var/log/xferlog/var/log/plesk/xferlog/var/log/secureCourier-IMAPThese logs record details such as user login attempts, email retrieval actions, and any errors encountered during IMAP sessions. Monitoring Courier-IMAP logs is essential for sysadmins to troubleshoot email-related issues, diagnose errors, and ensure the smooth functioning of email services hosted on Plesk servers./usr/local/psa/var/log/maillogPostfixPostfix logs document the activities and operations of the Postfix mail server on Plesk servers. These logs record information such as incoming and outgoing email delivery attempts, message routing, and any errors or warnings encountered during mail processing./usr/local/psa/var/log/maillogQmailQmail logs contain information about the operation and activities of the Qmail mail server on Plesk servers. These logs record details such as incoming and outgoing email delivery attempts, message queue management, and any errors or warnings encountered during mail processing./usr/local/psa/var/log/maillogHordeHorde logs document the activities and events occurring within the Horde webmail application integrated with Plesk. These logs capture user interactions, email operations, and system-related messages, providing valuable insights into the usage and performance of the webmail interface.Error log: /var/log/psa-horde/psa-horde.logRoundcubeMonitoring Roundcube logs is essential for sysadmins to troubleshoot user-reported issues, diagnose any errors encountered while using the webmail application, and ensure the smooth operation of email services hosted on Plesk servers.Error log: /var/log/plesk-roundcube/errorsSpamAssassinMonitoring SpamAssassin logs is crucial for sysadmins to assess the effectiveness of spam filtering, identify false positives or false negatives, and fine-tune spam detection rules to optimize email security./usr/local/psa/var/log/maillogParallels Premium AntivirusParallels Premium Antivirus logs contain records of antivirus scanning activities performed by the Parallels Premium Antivirus service within Plesk. These logs document scan results, detected threats, and any actions taken by the antivirus software to mitigate security risks./usr/local/psa/var/log/maillog/var/drweb/log/*Watchdog (monit)Watchdog (monit) logs capture monitoring and alerting events generated by the Watchdog service in Plesk. These logs provide detailed information about system health checks, service availability, resource usage, and any issues detected by the monitoring system. Monitoring Watchdog logs is essential for ensuring the stability, performance, and security of servers managed by Plesk./usr/local/psa/var/modules/watchdog/log/wdcollect.log/var/log/wdcollect.log/usr/local/psa/var/modules/watchdog/log/monit.log/var/log/plesk/modules/wdcollect.logLet’s EncryptLet’s Encrypt logs track the issuance and renewal of SSL/TLS certificates managed by the Let’s Encrypt service within Plesk. These logs provide valuable information about certificate generation, renewal attempts, validation challenges, and any errors encountered during the process./usr/local/psa/admin/logs/panel.logPlesk-PHPPlesk-PHP logs document the activities and errors related to the PHP-FPM service integrated with Plesk. These logs provide insights into the performance, execution, and errors encountered by PHP scripts running on the server. They are essential for troubleshooting PHP-related issues, diagnosing script errors, and optimizing the performance of PHP applications hosted on Plesk servers./var/log/plesk-php7x-fpm/Acronis BackupThe logs for Acronis Backup are used to track and record all activities related to backup and recovery operations performed by the Acronis Backup service. They provide detailed information about the status of backups, any errors or warnings encountered during the process, and other relevant data to ensure the reliability and integrity of the backup system./var/log/plesk/panel.log/var/log/trueimage-setup.log/opt/psa/var/modules/acronis-backup/srv/log/ConclusionIn conclusion, Linux logs are essential for system admins, serving as invaluable tools for gaining insights into system activities and effectively troubleshooting issues. To extract maximum value from them, it’s crucial to adhere to best practices.This includes managing logs well and focusing on critical ones. Also, optimize log analysis for system health. That means knowing where to look, prioritizing the crucial stuff, and fine-tuning your analysis for maximum efficiency. Nail these fundamentals, and you’ll be running your Linux setup like a well-oiled machine, spotting issues before they even have a chance to surface.Now that we’ve explored Linux logs, which ones are the most important in your experience? Share your thoughts with us in the comments below. Your input can help other admins improve their log management strategies and keep their systems running smoothly.