Three ways to back up informix-online

Informix-online database is widely used because of its high performance, high reliability, support data integrity definition/inspection and other characteristics. This paper mainly aims at summarizing and comparing three kinds of data backup methods commonly used in Informix-online database. (Note: Most of the backups in this article are backed up to hot backups on tape)

I. Using the Ontape tool for data backup

Features of the 1.ontape tools

The Ontape tool has the following functions: Backing up and restoring online data, backing up and restoring logical logs, changing database log status, and more (note: This article focuses on data backup capabilities).

2. Syntax for performing ontape backup data

The Ontape backup syntax is:

Ontape-s-l backup Level (0, 1, 2)

An Informix user or a user with DBA authority can make a backup by executing the above command when online is on line or still. Schedule 0, 1, 2-level backups according to the backup plan. A level 0 backup is a full backup of all data for the entire database, and a level 1 backup is only for data that has been modified after a level 0 backup, and a 2-level backup is a backup of data that has been modified since the level 1 backup.

3. Issues needing attention in data backup using the Ontape tool

(1) Make the correct settings for the Tapedev, TAPEBLK, tapesize parameters in the Onconfig file before performing the Ontape backup.

(2) in order to shorten the data recovery time, should be carried out at level 0 to minimize the level 1 and 2 backup. Data on important departments such as banks should be backed up at level 0 a day.

(3) If you need to restore the Ontape backup data to another server, the number and size of the two server models, operating systems, onconfig profiles, and unallocated dbspace disk space must be the same, otherwise the data will not recover properly.

(4) You must ensure that there are enough logical log files available. If the remaining logical log space is less than the 50%,informix-online of a single logical log, the backup operation is rejected. Before you can make a data backup, you must back up the logical logs that you have used.

(5) Keep a copy of the Onconfig file. After a level 0 backup, you should back up the Onconfig file, because you need to read Onconfig file information when you restore level 0 backup, if the online configuration is modified, data recovery will fail, and if you restore this level 0 backup, you must restore the configuration at that time.

(6) Backup can be online or static mode, in the backup process cannot change the way online, otherwise the backup will be interrupted.

(7) Do not use the background to perform backup commands (&& under Unix) because backups are performed interactively.