This is a multipart message in MIME format. --=_alternative 002FE02380256AEE_= Content-Type: text/plain; charset="us-ascii" Hi, The general response to the post below was that 4GB was far to much. However from there on feelings became mixed. Most people suggest that 2-3x physical memory was a suitable level to set the swap at. However, there was a few more detailed explanations that suggest that the level can be lower than this. It was highlighted by Simon Convey that having 2x physical memory was useful in the event of a panic, so that the entire physical memory could be dumped to disc for savecore to use on reboot. Matthew Stier points out that SunOS 4.x required 2x Physical memory for the kernel operation, but that with Solaris 2.x this requirement has disappeared and zero swap space is an option. More importantly, he mentioned an Openboot bug that means that crash dump recovery only works with partitions up to 2GB. Sergio Gelato highlighted the fact that /tmp is picked up from this space as well (important as several of the applications that we use often stream large files into /tmp when memory usage is at its most intense!). Finally, the award for a good dose of common sense goes to Ric Anderson who suggests running swap -r and sar -s to collect some information on Virtual Memory usage and make the decision based on this. Unfortunately, this does require careful examination of the systems over a period of operation, which of course I don't have time for right now. I have decided to go for a 2GB swap partition to avoid the problems highlighted by Matthew Stier and co., this will give plenty of space for swapping plus lots of disc space for the /tmp filesystem when it is strained. Many thanks to all who contributed. Bernard McAuley, Mindspeed Technologies, bernard.mcauley@mindspeed.com wrote: > > Hi, > > I'm updating some workstations to Solaris 2.7, and this gives me an > opportunity to 'tune' the workstations a bit. Currently they have 512 > MB of memory and 4GB of swap space. I have a vauge recollection that > 4x physical memory is a sensible level for swap space, but I have no > idea where this figure come from. In addition, I'm not sure how > suitable this is for our application (CAD Workstations and IC > Simulations). > > Can anybody out there give me a feel for a sensible level of swap > space, and more importantly, can they point me in the direction of > some literature on the topic of swap space configuration/usage in > solaris! > > Thanks, > > Bernard McAuley, > Mindspeed Technologies, --=_alternative 002FE02380256AEE_= Content-Type: text/html; charset="us-ascii" <br><font size=2 face="sans-serif">Hi,</font> <br> <br><font size=2 face="sans-serif">The general response to the post below was that 4GB was far to much. However from there on feelings became mixed. Most people suggest that 2-3x physical memory was a suitable level to set the swap at. However, there was a few more detailed explanations that suggest that the level can be lower than this. It was highlighted by Simon Convey that having 2x physical memory was useful in the event of a panic, so that the entire physical memory could be dumped to disc for savecore to use on reboot. Matthew Stier points out that SunOS 4.x required 2x Physical memory for the kernel operation, but that with Solaris 2.x this requirement has disappeared and zero swap space is an option. More importantly, he mentioned an Openboot bug that means that crash dump recovery only works with partitions up to 2GB.</font> <br> <br><font size=2 face="sans-serif">Sergio Gelato highlighted the fact that /tmp is picked up from this space as well (important as several of the applications that we use often stream large files into /tmp when memory usage is at its most intense!). Finally, the award for a good dose of common sense goes to Ric Anderson who suggests running swap -r and sar -s to collect some information on Virtual Memory usage and make the decision based on this. Unfortunately, this does require careful examination of the systems over a period of operation, which of course I don't have time for right now.</font> <br> <br><font size=2 face="sans-serif">I have decided to go for a 2GB swap partition to avoid the problems highlighted by Matthew Stier and co., this will give plenty of space for swapping plus lots of disc space for the /tmp filesystem when it is strained.</font> <br> <br><font size=2 face="sans-serif">Many thanks to all who contributed.</font> <br> <br><font size=2 face="sans-serif">Bernard McAuley,<br> Mindspeed Technologies,<br> </font> <br> <br><font size=2 face="Courier New">bernard.mcauley@mindspeed.com wrote:<br> > <br> > Hi,<br> > <br> > I'm updating some workstations to Solaris 2.7, and this gives me an<br> > opportunity to 'tune' the workstations a bit. Currently they have 512<br> > MB of memory and 4GB of swap space. I have a vauge recollection that<br> > 4x physical memory is a sensible level for swap space, but I have no<br> > idea where this figure come from. In addition, I'm not sure how<br> > suitable this is for our application (CAD Workstations and IC<br> > Simulations).<br> > <br> > Can anybody out there give me a feel for a sensible level of swap<br> > space, and more importantly, can they point me in the direction of<br> > some literature on the topic of swap space configuration/usage in<br> > solaris!<br> > <br> > Thanks,<br> > <br> > Bernard McAuley,<br> > Mindspeed Technologies,<br> </font> --=_alternative 002FE02380256AEE_=--Received on Tue Oct 23 09:45:53 2001
This archive was generated by hypermail 2.1.8 : Wed Mar 23 2016 - 16:32:34 EDT