Informix dbspace backups are known as “archives”. From version 14.10, these can be made on a Remote Standalone Secondary (RSS) replica system. This article describes the necessary configuration changes which are not well documented. The process is easy, but does require a restart of the RSS instance.
In a real case, we manage a multi-terabyte Informix 14.10 system which has both a local “High-availability Data Replication” (HDR) standby server and an RSS in another country for faster querying and to reduce traffic on the WAN link. We needed to be able to clone the RSS to a fourth system under testing without having to copy an archive across the WAN which would be very slow and affect other systems.
It can also be set to 2, which is undocumented but shown by the following command:
There are two other essential changes. Firstly, unless you disable logical log backups, the RSS will surprisingly try to do that, which you are unlikely to want. Whether you use “ontape” or “onbar” for archives, that should be avoided by setting the following configuration parameter only on the RSS system and restarting that instance:
Secondly, it is your responsibility to ensure that all database objects are logged. Any unlogged databases, RAW tables, or unlogged smart blobs cannot be replicated. By default, when you attempt an archive on RSS, it will check and refuse to continue if it finds any. Moreover, if you have large smart blob spaces, that process can be very lengthy, and cause a long checkpoint on the primary, of around 15 minutes in our case. This can be avoided with the following parameter available from IDS 14.10.FC8 onwards:
Note that the “oncheck” command above took 27 minutes on the real system, which is twice as slow as the built-in check.
You are then ready to run archives on the RSS system. There are three archive levels:
0 – all pages
1 – only those changed since the last level 0
2 – only those changed since the last level 1
The following example used “ontape” to create a level 0 archive on the RSS instance:
These messages were also recorded on the primary instance:
Tips & Tricks
HDR and RSS instances require that chunk paths are identical. However, you can create them on the same host for testing by using relative paths, as long as you start them while in the correct directory. Define shell aliases so you don’t forget, as in this case:
This is only supported on RSS servers at this time, not HDR.
You only need to set the configuration parameters listed in this article and restart an RSS instance for local archives to be possible.
Suggestions above are provided “as is” without warranty of any kind, either express or implied, including without limitation any implied warranties of condition, uninterrupted use, merchantability, fitness for a particular purpose, or non-infringement.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.