First off, please turn off the HTML in eamil. Thank you. On Sat, Sep 30, 2006 at 04:19:08PM +0300, nicolas angel wrote: > > Hi, i would to ask something about swap space: > i quote from the book "How Linux WorksWhat Every Super-User Should Know" > "Reserve two to five times as much disk space as you have real memory for > swap. It doesn't make sense to go any lower, because you may actually risk > running out of memory. If you go higher and actually intend to use all of > this swap space, you will likely suffer serious performance problems because > the system will spend all of its time swapping (a condition known as > thrashing). " > i can't understand why if create a really big swap partition i will have a > performance decrease????It seems to me > that in the worst case scenario, i will be throwing disk space [because the > system will never use the swap partition if it doesn't need it......why this > would have a negative impact on the system......] > thanks in advance, > Nicolas Ang The key to it is the conditions: "If you go higher [than four times physical RAM] and actually intend to use all of this swap space,..." It is how much swap space you use, not how much you have, that is critical. The more swap space you have in use, the higher the likelihood that a given page is in swap space rather than in physical memory when needed, so the more the disk drive moves to get to swapped pages, so the slower things appear to run. The solution is to have more physical memory. The rule of thumb to which I am accustomed is to have twice as much swap space as physical memory. Of late I have been pushing that. However the fact that I can get away with it doesn't say much, because I have so much physical memory that I use very little swap space. -- Charles Curley /"\ ASCII Ribbon Campaign Looking for fine software \ / Respect for open standards and/or writing? X No HTML/RTF in email http://www.charlescurley.com / \ No M$ Word docs in email Key fingerprint = CE5C 6645 A45A 64E4 94C0 809C FFF6 4C48 4ECD DFDB
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