On 26/08/11 01:18, George Gallen wrote: > But swap space isn't really memory, it's disk and nowhere near as fast as > memory, and (I don't know for sure) probably > even far slower than SSD's. > > In reality, if your creating a tempfs partition for the speed of memory vs > disk, then using swap space defeats the purpose. > Agreed (partially :-)
If your access is lumpy, or (not in this case) you are creating zillions of files, or probably some other reasons, it still makes sense. For example, in my case (gentoo emerge) it creates lots of small files that it creates, uses, then forgets about. By using tmpfs, they don't get flushed to disk in the normal course of events, and if they do, chances are I no longer care. And the OP didn't mention speed. Maybe that's not why he wanted ramdisk? After all, isn't the whole point of Pick that a memory-starved Pick machine can still outrun an Oracle with ram coming out its ears? :-) Cheers, Wol > George Gallen > Senior Programmer/Analyst > Accounting/Data Division > ggal...@wyanokegroup.com > ph:856.848.9005 Ext 220 > The Wyanoke Group > http://www.wyanokegroup.com > ________________________________________ > From: u2-users-boun...@listserver.u2ug.org > [u2-users-boun...@listserver.u2ug.org] On Behalf Of Wols Lists > [antli...@youngman.org.uk] > Sent: Thursday, August 25, 2011 7:28 PM > To: u2-users@listserver.u2ug.org > Subject: Re: [U2] Why Pick U2? > > On 25/08/11 16:47, George Gallen wrote: >> keep in mind: >> >> SSD drives have a limited number of writes (much better today than before) >> tempfs do not (or at least I don't think so) >> SSD drives however usually can store a LOT more than a tempfs file, which >> depends on your physical memory - You couldn't create a 100GB tempfs >> if you wanted to > > Completely wrong ... :-) > > My /tmp dir happens to be 8Gb in size - on a system with 8Gb of ram. I > *also* have a 20Gb /var/tmp/portage. Both of these are tmpfs systems, so > I have 28Gb of tmpfs on a system with only 8Gb of ram :-) > > That said, you must have sufficient total memory - I've got something in > excess of 40Gb of total address space. I'm not sure how big my swap > partitions are, but there's more than 32Gb (my rule is at least twice > the mobo's max ram capacity, and with 1.5Tb of disk space, that's > peanuts :-) > > But ram disks do default to half available ram, and that burnt me when I > first hit it... > >> SSD drives don't forget when you reboot >> > But that's the whole point of ram disks :-) > > Cheers, > Wol > _______________________________________________ > U2-Users mailing list > U2-Users@listserver.u2ug.org > http://listserver.u2ug.org/mailman/listinfo/u2-users > _______________________________________________ > U2-Users mailing list > U2-Users@listserver.u2ug.org > http://listserver.u2ug.org/mailman/listinfo/u2-users > _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
