Vess R3000 Series offers 3 kinds of Sync Modes when creating new NAS Shares and new Volumes at Advanced Pool as follows.
Choosing a sync mode is to determine the synchronous behavior of transactions.
1].Standard - means that synchronous share transactions, such as fsync, O_DSYNC, O_SYNC, and so on, are written to the intent log.
2].Always - ensures that every share transaction is written and flushed to stable storage by a returning system call. This value has a significant performance penalty. The default value is Always.
3].Disabled - means that synchronous requests are disabled. Share transactions are only committed to stable storage on the next transaction group commit, which might be after many seconds. This value gives the best performance,
Caution: This disabled value is dangerous because file system is ignoring the synchronous transaction demands of applications, such as databases or NFS operations. Setting this value on the currently active root or via share might result in unexpected behavior, application data loss, or increased vulnerability to replay attacks. You might only use this value if you fully understand all the associated risks.
We can choose any one of them under the “Expand Advanced Settings” option in the Web Interface.