Re: [gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?
On Sonntag 31 Mai 2009, Grant wrote: > I recently disabled swap and mounted /tmp on tmpfs for a netbook since > the SSD is so slow, and now I'm wondering if that would be a wise move > for all of my Gentoo systems. In what type of situation would it be a > bad idea? > >>> > >>> Instead of disabling swap, just make it small (like 32MB or something; > >>> whatever the smallest allowable partition size is). The kernel needs > >>> swap to operate optimally, even if it's extremely small. Just make > >>> sure it's there. > >> > >> Hmm, on this old box I noticed swap was using more than 135,000K earlier > >> today as I was emerging xulrunner and ImageMagick. I think that the > >> size of swap is relevant to the memory size that the box in question > >> has. Not all machines have found their way to 2G RAM yet ... ;) > > > > Don't forget that you can set swapiness too. This is set in > > /etc/sysctl.conf and for mine I have this: > > > > vm.swappiness = 30 > > > > The lower the number, the less chance of it using swap. If it is set to > > 90, it will use a lot of swap which is fine if you have little ram or a > > really fast drive. If it is set to 30, then it will not use swap unless > > it is basically out of ram. > > > > With the setting of 30, mine uses swap when compiling OOo or some other > > large package or if I am opening a TON of pics. Otherwise, swap is at 0 > > or close to it even after being up a long time. I have 2Gbs here tho. > > Your mileage may vary. > > > > Dale > > Thanks Dale. Should "vm.swappiness = 30" work well on all systems? > My Gentoo systems have vastly different specs and duties so I love > tweaks that always improve things. It sounds like /tmp on tmpfs is > one of those. > > - Grant you can set swappiness = 0 which works even better, because the kernel will only swap if it really has too.
Re: [gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?
Grant wrote: > I recently disabled swap and mounted /tmp on tmpfs for a netbook since > the SSD is so slow, and now I'm wondering if that would be a wise move > for all of my Gentoo systems. In what type of situation would it be a > bad idea? > > Instead of disabling swap, just make it small (like 32MB or something; whatever the smallest allowable partition size is). The kernel needs swap to operate optimally, even if it's extremely small. Just make sure it's there. >>> Hmm, on this old box I noticed swap was using more than 135,000K earlier >>> today >>> as I was emerging xulrunner and ImageMagick. I think that the size of swap >>> is relevant to the memory size that the box in question has. Not all >>> machines have found their way to 2G RAM yet ... ;) >>> >>> >>> >> Don't forget that you can set swapiness too. This is set in >> /etc/sysctl.conf and for mine I have this: >> >> vm.swappiness = 30 >> >> The lower the number, the less chance of it using swap. If it is set to >> 90, it will use a lot of swap which is fine if you have little ram or a >> really fast drive. If it is set to 30, then it will not use swap unless >> it is basically out of ram. >> >> With the setting of 30, mine uses swap when compiling OOo or some other >> large package or if I am opening a TON of pics. Otherwise, swap is at 0 >> or close to it even after being up a long time. I have 2Gbs here tho. >> Your mileage may vary. >> >> Dale >> > > Thanks Dale. Should "vm.swappiness = 30" work well on all systems? > My Gentoo systems have vastly different specs and duties so I love > tweaks that always improve things. It sounds like /tmp on tmpfs is > one of those. > > - Grant > > > I'm on x86 and I really don't know where the vm part came from. It could have been me that put it there but I think it may have gotten updated somewhere along the way. I'm not sure what would update that tho. May be worth a google for your arch and just swappiness and see what else can be in front of it. I used to have it set to 70 when I only had 512MBs of ram. It would use swap pretty regular, even just for caching stuff. So, the setting does work for sure. If you wanted it to use swap only to prevent the system from crashing, I would assume you could set it to 10 or something like that. If you have a really fast drive, SATA or something, then you could set it to 90 and let it use swap all it wants. Dale :-) :-)
Re: [gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?
I recently disabled swap and mounted /tmp on tmpfs for a netbook since the SSD is so slow, and now I'm wondering if that would be a wise move for all of my Gentoo systems. In what type of situation would it be a bad idea? >>> Instead of disabling swap, just make it small (like 32MB or something; >>> whatever the smallest allowable partition size is). The kernel needs >>> swap to operate optimally, even if it's extremely small. Just make sure >>> it's there. >>> >> >> Hmm, on this old box I noticed swap was using more than 135,000K earlier >> today >> as I was emerging xulrunner and ImageMagick. I think that the size of swap >> is relevant to the memory size that the box in question has. Not all >> machines have found their way to 2G RAM yet ... ;) >> >> > > Don't forget that you can set swapiness too. This is set in > /etc/sysctl.conf and for mine I have this: > > vm.swappiness = 30 > > The lower the number, the less chance of it using swap. If it is set to > 90, it will use a lot of swap which is fine if you have little ram or a > really fast drive. If it is set to 30, then it will not use swap unless > it is basically out of ram. > > With the setting of 30, mine uses swap when compiling OOo or some other > large package or if I am opening a TON of pics. Otherwise, swap is at 0 > or close to it even after being up a long time. I have 2Gbs here tho. > Your mileage may vary. > > Dale Thanks Dale. Should "vm.swappiness = 30" work well on all systems? My Gentoo systems have vastly different specs and duties so I love tweaks that always improve things. It sounds like /tmp on tmpfs is one of those. - Grant
Re: [gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?
Mick wrote: > On Saturday 30 May 2009, Nikos Chantziaras wrote: > >> Grant wrote: >> >>> I recently disabled swap and mounted /tmp on tmpfs for a netbook since >>> the SSD is so slow, and now I'm wondering if that would be a wise move >>> for all of my Gentoo systems. In what type of situation would it be a >>> bad idea? >>> >> Instead of disabling swap, just make it small (like 32MB or something; >> whatever the smallest allowable partition size is). The kernel needs >> swap to operate optimally, even if it's extremely small. Just make sure >> it's there. >> > > Hmm, on this old box I noticed swap was using more than 135,000K earlier > today > as I was emerging xulrunner and ImageMagick. I think that the size of swap > is relevant to the memory size that the box in question has. Not all > machines have found their way to 2G RAM yet ... ;) > > Don't forget that you can set swapiness too. This is set in /etc/sysctl.conf and for mine I have this: vm.swappiness = 30 The lower the number, the less chance of it using swap. If it is set to 90, it will use a lot of swap which is fine if you have little ram or a really fast drive. If it is set to 30, then it will not use swap unless it is basically out of ram. With the setting of 30, mine uses swap when compiling OOo or some other large package or if I am opening a TON of pics. Otherwise, swap is at 0 or close to it even after being up a long time. I have 2Gbs here tho. Your mileage may vary. Dale :-) :-)
Re: [gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?
On Saturday 30 May 2009, Nikos Chantziaras wrote: > Grant wrote: > > I recently disabled swap and mounted /tmp on tmpfs for a netbook since > > the SSD is so slow, and now I'm wondering if that would be a wise move > > for all of my Gentoo systems. In what type of situation would it be a > > bad idea? > > Instead of disabling swap, just make it small (like 32MB or something; > whatever the smallest allowable partition size is). The kernel needs > swap to operate optimally, even if it's extremely small. Just make sure > it's there. Hmm, on this old box I noticed swap was using more than 135,000K earlier today as I was emerging xulrunner and ImageMagick. I think that the size of swap is relevant to the memory size that the box in question has. Not all machines have found their way to 2G RAM yet ... ;) -- Regards, Mick signature.asc Description: This is a digitally signed message part.
[gentoo-user] Re: Disabling swap & mounting /tmp on tmpfs = new standard?
Grant wrote: I recently disabled swap and mounted /tmp on tmpfs for a netbook since the SSD is so slow, and now I'm wondering if that would be a wise move for all of my Gentoo systems. In what type of situation would it be a bad idea? Instead of disabling swap, just make it small (like 32MB or something; whatever the smallest allowable partition size is). The kernel needs swap to operate optimally, even if it's extremely small. Just make sure it's there. Mounting /tmp as tmpfs improves speed, so no problems there. You might want to mount /var/tmp/portage as tmpfs too, that will give nice speed gains during emerge (if you have the RAM for it; a 2GB /var/tmp/portage should be enough for almost anything except OpenOffice, you'll have to umount to emerge that one.)
