How to add storage capacity to existing grids

[PeterNic]

The easiest way to add storage is to simply add more servers (nodes). This will ensure you also have more I/O capacity. Then, if you have too many servers, remove some of the older servers (after migrating their volumes to the new servers). This is the preferred way to do it.

If you want to add HDD capacity to an existing server, you will need to remove the server from the grid, replace or add HDD, and re-add the server. Once the server is added back, you will need to repair the volumes that had streams on that servers (as the streams will be deleted/lost when you remove the server). Before taking down and removing any server, please make sure all volumes are repaired (force volume check – “vol check” - and see the status with “vol repair –status”)

[tonyjun]

I think 3tera should be release more document about how to maintain physics device, like server upgrade, server breakdown,switch upgrade etc.

[PeterNic]

Tony,

Thank you for the suggestion - I will be happy to pass your note to our documentation team.

In the meantime, we keep things simple. Unlike in traditional server environments, where servers content is precious, in AppLogic servers are more like worker bees - there is nothing unique stored on any individual server. As a result, there are no complex processes to patch or upgrade individual servers - if you want to modify a server, take it out of the grid, modify it and then add it as a new server. (Remember to check/repair volumes before taking down any server, and after returning it. This will help prevent data loss in case you have broken volume mirrors.)

In most AppLogic systems, the servers are build-and-run; they don't get a lot of upgrades. Usually, as you have bigger, better servers, you either set up a new grid or simply add them to an existing grid and remove the old servers. This way the cost of managing the servers is much lower.

I know the above does not cover all cases, including replacement-after-failure. If you have questions on specific upgrade or replacement use cases, please post here and either our team or one of the many community members will provide advice.

Best regards,
- Peter

[tonyjun]

Thanks Peter