when i use two device swap,(one primary ,one on the other disk), are they be used simutanious or

[常有慈悲心]

are they be used at same time or used one by one?

[Slawomir Gora · Accepted solution]

Hi,

I think that one by one.

[Slawomir Gora]

Hi,

priority indicates the order in which the swap space from the device. Space is taken from the lower-priority systems first.

[Rajeev Shukla]

If you configure one as primary swap and the second as secondary swap then after the first is used the second will be used, but if both have same priority and then both will be used simultaneously

[Sยภเl Kย๓คг]

I don't think if both have same priority simultanious utilization happens.If both have same priority the primary,then secondary.
regards
SK

[jaganmohan]

Rajeev Shukla's reply is absolutely correct.

[Sridhar Bhaskarla]

Hi China,

Priority of 'primary swap' is set to 1 by default. This will allow you to specify the 'secondary swap' at a higher priority '0' (lower number) so that it will be used first. If it is 1, then interleaving will happen so they will both be accessed alternatively as per your swchunk size setting. If it is set to > 1, then primary swap will be used first and then the secondary.

However, if this is a production system, then considering the priorities may not make much sense as you will be affecting the production. But it is a good practice though. Never set the priorities equal on two swap volumes on the same disk.

-Sri

[Bill Hassell]

In the old days of RAM less than 1000megs, swap priorities, speed of disks, location of swap by channels, etc was fairly important. Today, swap (paging) is far too expensive in terms of performance to allow any significant amount, so priority is not meaningful. The swap is used in a round robin assignment method for equal priorities, but if performance is a concern, don't mess with swap--BUY MORE RAM so you don't have to be concerned. Paging to the swap area, no matter how fast the disk may be, is a huge performance penalty.