Difference between revisions of "Swap"

Swap space is disk space used by Linux (and most other operating systems) to store objects from memory when real physical memory starts becoming crowded or is exhausted. Because disk is generally slower than memory, Linux stores in swap the least recently used objects first, and keeps as much as it can in memory. It's generally recommended to have a swap space equal in size to your memory, if possible. See more details about swap space [https://help.ubuntu.com/community/SwapFaq here].

Swap space is disk space used by Linux (and most other operating systems) to store objects from memory when real physical memory starts becoming crowded or is exhausted. Because disk is generally slower than memory, Linux stores in swap the least recently used objects first, and keeps as much as it can in memory. It's generally recommended to have a swap space equal in size to your memory, if possible. See more details about swap space [https://help.ubuntu.com/community/SwapFaq here].

The Ubuntu 12.04 LTS AMI, which I also started with, is configured with no swap space initially, as the size and number of your storage devices can vary. But most come with a large free ephemeral storage device automatically. Since S3 storage is limited by cost, the ephemeral drive is a good place for a swap file. Mine has the same device name mentioned in the question, /dev/xvdb, but you can configure this during instance launch.

The Ubuntu 12.04 LTS AMI, which I also started with, is configured with no swap space initially, as the size and number of your storage devices can vary. But most come with a large free ephemeral storage device automatically. Since S3 storage is limited by cost, the ephemeral drive is a good place for a swap file. Mine has the same device name mentioned in the question, /dev/xvdb, but you can configure this during instance launch.