https://community.hpe.com/t5/operating-system-tru64-unix/the-swap-mode/m-p/3079924#M7628 RTFM! Or Google! or Manpage or Online Doc.!<BR /><BR />Did you simply google +lazy +eager +unix? You'll get plenty of explanations.<BR /><BR />One place to read up on this on the system is under "man swapon"... if you know what to look for as it is called "deferred mode" and "immediate mode" there.<BR />Also check sysconfig.<BR /><BR />-- <A href="http://www.ptc.com/partners/hardware/2000i2/faq/dec_faq.htm#3a" target="_blank">http://www.ptc.com/partners/hardware/2000i2/faq/dec_faq.htm#3a</A> :<BR />Tru64 Unix has two swap modes; the default is called "eager" mode and the alternate is called <BR />"overcommit" or "lazy" swap mode. In eager swap mode, the operating system reserves swap <BR />space for a process whenever it makes a request for memory. That way if it ever needs to be <BR />swapped out, it has somewhere to store it's pages in the swap area(s). In "lazy" swap mode, swap <BR />space is used by a process only when it needs to be paged to disk. <BR /><BR />What are the advantages and disadvantages? <BR />In "eager" swap mode, a process always has a place to go if it needs to be paged out. In "lazy" <BR />mode, if a process needs to be paged out and there is no place in the swap area to go, the OS will <BR />start killing off other idle processes to make room for the active process to go to the swap <BR />partition(s). This can be dangerous and it is for this reason that it is generally not recommended <BR />to run in "lazy" swap mode. This is especially true for multi-user servers where users' processes <BR />could be killed off seemingly at random. However, for single user workstations, this can be more <BR />of an acceptable risk. If you are getting a lot of "Swap space below 10% free" messages in the <BR />console window and do not have any additional free disk space to add more swap, switching to <BR />"lazy" mode can usually alleviate these messages. This is because in "eager" swap mode, the <BR />virtual memory of the system is essentially equal to the amount of swap space configured (every <BR />process reserves it's space). In "lazy" swap mode, virtual memory = physical RAM + swap space <BR />(swap isn't used until it's needed). "Lazy" swap mode also seems to have a slight performance <BR />advantage because the OS doesn't have to reserve swap space for a process whenever it asks for <BR />more memory. <BR /><BR /> Sun, 28 Sep 2003 12:13:38 GMT Hein van den Heuvel 2003-09-28T12:13:38Z https://community.hpe.com/t5/operating-system-tru64-unix/the-swap-mode/m-p/3079923#M7627 Hi all,<BR /> who can tell me the two swap mode:laze and <BR />eager.thanks!<BR /><BR /> Sun, 28 Sep 2003 01:40:31 GMT https://community.hpe.com/t5/operating-system-tru64-unix/the-swap-mode/m-p/3079923#M7627 naVigAtor 2003-09-28T01:40:31Z https://community.hpe.com/t5/operating-system-tru64-unix/the-swap-mode/m-p/3079924#M7628 RTFM! Or Google! or Manpage or Online Doc.!<BR /><BR />Did you simply google +lazy +eager +unix? You'll get plenty of explanations.<BR /><BR />One place to read up on this on the system is under "man swapon"... if you know what to look for as it is called "deferred mode" and "immediate mode" there.<BR />Also check sysconfig.<BR /><BR />-- <A href="http://www.ptc.com/partners/hardware/2000i2/faq/dec_faq.htm#3a" target="_blank">http://www.ptc.com/partners/hardware/2000i2/faq/dec_faq.htm#3a</A> :<BR />Tru64 Unix has two swap modes; the default is called "eager" mode and the alternate is called <BR />"overcommit" or "lazy" swap mode. In eager swap mode, the operating system reserves swap <BR />space for a process whenever it makes a request for memory. That way if it ever needs to be <BR />swapped out, it has somewhere to store it's pages in the swap area(s). In "lazy" swap mode, swap <BR />space is used by a process only when it needs to be paged to disk. <BR /><BR />What are the advantages and disadvantages? <BR />In "eager" swap mode, a process always has a place to go if it needs to be paged out. In "lazy" <BR />mode, if a process needs to be paged out and there is no place in the swap area to go, the OS will <BR />start killing off other idle processes to make room for the active process to go to the swap <BR />partition(s). This can be dangerous and it is for this reason that it is generally not recommended <BR />to run in "lazy" swap mode. This is especially true for multi-user servers where users' processes <BR />could be killed off seemingly at random. However, for single user workstations, this can be more <BR />of an acceptable risk. If you are getting a lot of "Swap space below 10% free" messages in the <BR />console window and do not have any additional free disk space to add more swap, switching to <BR />"lazy" mode can usually alleviate these messages. This is because in "eager" swap mode, the <BR />virtual memory of the system is essentially equal to the amount of swap space configured (every <BR />process reserves it's space). In "lazy" swap mode, virtual memory = physical RAM + swap space <BR />(swap isn't used until it's needed). "Lazy" swap mode also seems to have a slight performance <BR />advantage because the OS doesn't have to reserve swap space for a process whenever it asks for <BR />more memory. <BR /><BR /> Sun, 28 Sep 2003 12:13:38 GMT https://community.hpe.com/t5/operating-system-tru64-unix/the-swap-mode/m-p/3079924#M7628 Hein van den Heuvel 2003-09-28T12:13:38Z