Ray, excellent overview and good job at layman-ising the terminology used. Thank you.
Ronni, thanks for the extra detail ... I was beginning to doubt my grasp of English. Robin, thanks for the note that recent Safari updates actually address these issues. I'd seen and installed the latest OS update (ie. 10.7.4), which MIGHT have been the things which solved my problem, but on running Software Update saw that there was also a Safari update. Installed that 12 May (version 5.1.7) and at this point, my hard disk capacity remains at the capacity it was when I last restarted, whereas by now it probably would have dwindled. Fingers crossed that whatever memory leakage problem had crept in has been knocked on the head. I do use Safari mostly, occasionally Firefox for websites which Safari has trouble with, and often have many tabs (10, 20, 30) open at any one time before I get chance and close a few back down. Cheers, Steven On 12/05/2012, at 5:31 PM, Robin Belford wrote: > Steven, > The most likely issue is that your memory leakage is caused by a browser you > are running. You haven't said what you are using, but bit recent versions of > both Firefox and Safari have had memory leak issues. Once this happens you > start getting many pageouts to disk and your system slows and the HD fills up. > Both of the offending browsers have been updated in the past week, Safari > twice, addressing these issues. > I suggest you ensure you are running the latest version of your browser and > see if the problem persists. > If you don't want to upgrade then I suggest shutting down your computer and > restarting once a day. > > If you continue to experience the problem you then will need to identify what > other programs you are using when this occurs, a frequent culprit, due to its > memory requirements for scratch files, is Photoshop which allocates, often > large, scratch files to the HD. > > > robin On 12/05/2012, at 12:52 PM, Ronda Brown wrote: > Hi Steven, > > I understand your confusion, it always confused me ;-) The confusion began in > Leopard... > In OSX Leopard rather than giving a ‘count’ of 'page in' and 'page outs', it > gives a size in GB of the amount of RAM that has been paged in or out. > > The numbers are smaller but the same principals apply. > > In OSX Lion there is a new entry called ‘Swap Used’. This is a count of how > much Disk Space your computer is using as RAM and it’s a good rough estimate > of the minimum amount of extra RAM you need. > > Example If your Swap used is 4GB then get AT LEAST 4GB more RAM. > > Steven, Open the Terminal application in your Utilities folder and at the > prompt enter: > top > > Then press RETURN. You will see a paragraph of output at the top of the > display of processes. > Look for two entries, "pageins and pageouts." > They come near the end of the paragraph. > There you will see the 'count' ... > Mine just now are: 641506(0) pageins, 451(0) pageouts. > > Cheers, > Ronni On 12/05/2012, at 12:49 PM, Ray Forma wrote: > Steven, > > The 'System Memory' part of 'Activity Monitor' is slightly arcane, so to help > you get a better understanding of memory and OS X I have, from several > sources, plagiarised and modified the following. I hope this is clearer than > mud: > > 1 all memory in OS X is 'virtual'. Some of that virtual memory is in RAM, > some in system and application files on the hard drive, and some may be in > swapfiles on the hard drive. > > 2 Wired RAM is memory that the OS pernamently 'locks' and you cannot make it > inactive or move it to swapfiles. It must be there for the operation of the > OS. > > 3 Active RAM is memory that is currently in use by either the system or an > application. > > 4 Think of Inactive RAM as a first stage swapfile. It contains instructions > and data that are not currently in use in the OS or an application, but the > OS leaves it in RAM in the event these instructions and data are needed > again. If more Active RAM is needed, the Inactive RAM will be reassigned, and > if it contains data for a currently open application, those data will be > written out to a swapfile on the HD. If you have closed the application then > the memory will simply be overwritten. > > 5 Free RAM is RAM that is currently not mapped into Wired, Active, or > Inactive RAM. If more Active RAM is needed, the OS will first remap any > available Free RAM into Active status. [Free RAM does not mean it costs > nothing to buy] > > 6 Swapfiles are files on your HD that the OS uses to store data being used > by currently open applications for which there is currently no room in either > Active or Inactive RAM > > 7 System resources, fonts, application files, and frameworks (shared > libraries) are mapped into the virtual memory address space for each > application whether they are in Wired, RAM Active RAM, Inactive RAM, or in > system files on the HD. The OS never puts such system resources into the > swapfile or files because such files are already available on the hard drive > and there is no point in duplicating the code. > > 8 Pageins occur anytime something is moved into Active RAM whether that is > from Inactive RAM, the swapfile or files on your HD, or some other file on > the hard drive. Pageins are measured in amounts of data, not in numbers of > pages. > > 9 Pagouts occur anytime anything is moved out of Active RAM. This includes > mapping into Inactive RAM, as well as writing to a Swapfile. Only data are > ever written to the hard drive since instructions are already stored on the > hard drive. Pageouts are measured in amounts of data, not in numbers of pages. > > 10 The OS breaks your memory space up into 'pages'. Applications that need > access to data that is in memory call the data by page. > > 11 If an application calls for a page and it is in the RAM, then a 'page in' > is registered. > > 12 If an app calls for a page from memory, and that page is currently stored > in a swapfile on the hard disk and has to be read back into the RAM, then a > 'Page Out' is registered. A 'Page-out' slows down the operation of the > computer because the OS has to read the data from your hard disk into RAM > first, rather than reading straight from the RAM. Hard disks take over 300 > times longer to transfer a page of data, compared with reading from RAM. This > soon adds up to slow overall performance. > > 13 If page-outs exceed page-ins, you definitely don't have enough RAM. > Ideally, page-outs should be less than 20% of the number of page-ins. You > should aim for less than 5%. > > 14 The only ways to reduce page-outs are adding more RAM, or reducing the > number of open applications. While freeing up memory by working with fewer > and smaller files and apps may help, more RAM is the only reasaonable > solution. > > On 12/05/2012, at 3:38 AM, Steven Knowles <emai...@knowles.net.au> wrote: > >> I'm running 10.7.3 on a 17" MBP which is probably getting a bit aged these >> days, 2.4 GHz Intel Core Due, 4 GB 667 MHz DDR2 SDRAM. >> >> At startup, I have around 50GB of spare hard disk capacity, of a total 250GB >> disk. >> >> Over the past month o so, what happens is that over around a 2 to 4 day >> period, the machine gets slower and slower, to the point that it's >> unbearably slow, so a restart becomes necessary. >> >> In line with the progression of slowness, seems to be disappearance of hard >> disk capacity. By the time I have to restart, a quick check of hard disk >> capacity, and it's down to around 1 or 2GB. >> >> Trash is emptied regularly (I almost always use Secure Empty Trash). >> >> Any clues as to what might be causing this? >> >> I've just noticed 10.7.4 is out, so I'll update to that to see if that makes >> a difference, but any hints in the meantime would be appreciated. >> >> Cheers, Steven > > Regards, > > Ray Forma > Mob +61 (0) 428 596938 -- The WA Macintosh User Group Mailing List -- Archives - <http://www.wamug.org.au/mailinglist/archives.shtml> Guidelines - <http://www.wamug.org.au/mailinglist/guidelines.shtml> Settings & Unsubscribe - <http://lists.wamug.org.au/listinfo/wamug.org.au-wamug>
