I started a couple servers on EC2 and they don't have swap.
Am I doing something wrong or is it that the machines just don't have any?
I've launched something that took lots of memory and now everything lags a lot. I guess all applications' memory has gone to swap in order to free some space for the memory-intensive process, and now everything is slowly returning to RAM when accessed.
Is there a way to explicitly move everything possible from swap back to RAM? Or maybe not everything, but just some particular processes data?
I am using RAM for storing some of my database tables and the others are stored in hard disk.
Today I came to know that my processes are using swap memory. Now what is swap memory and how can I detect that which process is using swap memory and how can i stop them from using it?
What is better for performance? A partition closer to the inside of the disk will have slower access times, and we must wait for the drive to switch between the OS and swap partitions.
On the other hand, a swap partition bypasses all of the filesystem allowing writes to the disk directly, which can be faster than a file.
What is the performance trade off?
How much does having a fixed size swapfile make a difference?
Is it a case that it will be longer to change to the swap partition, but performance will be better while it is on the swap partition that if it had been a swap file?
How should I decide what size to make my swap on a new Linux machine (Debian) with 2-4 GB of RAM? Do I really need swap space?