On 11/04/2010 10:30 PM, David Burgess wrote: > On Thu, Nov 4, 2010 at 7:43 PM, Jeff Siddall <[email protected]> wrote: > >> With RAM as cheap as it is that is not a tough or expensive thing to do, >> but does losing everything in /tmp on a reboot cause any problems? > > /tmp is always cleared on a reboot, even if it's in persistent > storage, so a ramdisk has no disadvantage in this regard.
Ummm... not in Red Hat-like systems. I have files dating back to 2007 in my /tmp! >> The next obvious question is whether it creates any benefits? Â Giving up >> a gig of RAM also means giving up a gig of cache, and that has a >> performance penalty also. > > The ramdisk only takes away from RAM when it's in use. Check out these > numbers: > Notice that I have 15 ramdisks, each with 2.0GB of capacity. I only > have 4GB of system RAM, yet, I still have around 2GB of free RAM. It's > free until one of those ramdisks actually uses it. OK, granted. But that begs another question: what happens if your free RAM is used for cache/buffers -- which it almost certainly will be? Is the cost/time required to free RAM guaranteed to be less than using platter disks? >> I have seen people mention that /tmp gets used a lot on LTSP servers, >> but what exactly is using it, and how can I tell if removing that from >> my platter disks will reduce IO delays on my system? > > There are programs for analyzing the type of IO going on in your > system. The only one I can name off the top of my head is iotop, which > gives an instantaneous view, but there are others that can give you > more of a section or summary. Yeah I use iotop, but it doesn't tell you how much of the disk IO is spent in /tmp. I'll dig some more. Jeff ------------------------------------------------------------------------------ The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book "Blueprint to a Billion" shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
