Re: what is sufficient free memory?
70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff Swap: 104380K av, 3128K used, 101252K free 35860K cached This doesen't look like a problem but like a perfectly healthy server. No metter how much RAM you put in it there'll always be only about 2 megs left, because of machine's fs caching, that uses any free ram to hold pieces of often used files. all-in-one box running DNS, squid, postfix, apache and radius (I have 17 modems on it's cyclades). Any recommendations on the bare-minimum RAM for this configuration? The suits at our purchasing division are 64Megs if perfectly enough, i know people that used to run such boxes witch 16Megs of ram. What you should look at is swap that is used (3 megs? only? and that's a problem? ) need to know if I need to demand that they immediately cough-up the 128mb (or more). now of course you should demand more ram, common, squid is a real memory hogger, but you can tell it how much ram you want it to use (things like cache_mem etc), , apache can eat memory like crazy ( especially mine, with perl modules compiled in ) regards, Eyck
Re: what is sufficient free memory?
sorry for my last post, I haven't noticed that you people told everything already. To paint a better picture, here's an entire top screen: just a little hint - don't sort your processes by cpu usage when you want to check memory usage ( just press big 'M' and it'll all clear up ) regards, slow Eyck
what is sufficient free memory?
Hello All, I had problems with the RAM (128MB SDRAM DIMM) of my server and the only spare I had was (64MB SDRAM DIMM). Hear is what top says: 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff Swap: 104380K av, 3128K used, 101252K free 35860K cached I'm a little worried that the harddisk might thrash as there's hardly any more memory to spare (1828K free). This server is pretty much an "all-in-one" box running DNS, squid, postfix, apache and radius (I have 17 modems on it's cyclades). Any recommendations on the "bare-minimum" RAM for this configuration? The suits at our purchasing division are "stiff" at best so when I make the requesition for the replacement, I need to know if I need to "demand" that they "immediately" cough-up the 128mb (or more). Thanks in advance, Erik -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
what is sufficient free memory?
Your biggest potential hog is squid. It maintains data structures in memory and their size grows with your cache size. If anything causes trashing that'll be it. The squid FAQ's give some back-of-envelope calculations for this AFAIK. cheers, BM -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: what is sufficient free memory?
On Wed, 30 Aug 2000, Erik Peter P. Abella wrote: 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff Swap: 104380K av, 3128K used, 101252K free 35860K cached I'm a little worried that the harddisk might thrash as there's hardly any more memory to spare (1828K free). This server is pretty much an of that 61296 used k, 35860k is cache. filesystem cache. things happened so that linux uses the memory if it has. would it make any sense having unused memory ? ok, it's cheap these days, but not _that_ cheap... -- [-] ``And there are plenty of other innovative pieces of software such as Napster and ICQ.'' -- comment on ``Systems Software Research is Irrelevant'' at http://freshmeat.net/news/2000/08/05/965534399.html -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: what is sufficient free memory?
Erik, linux will always use almost 100% of the memory (unless you have a BUTTLOAD of extra (ie. 512MB RAM)) for buffers and things like that. For example: skank:~# free total used free sharedbuffers cached Mem: 62956 61460 1496 15432 2064 12864 -/+ buffers/cache: 46532 16424 Swap: 102780 15476 87304 I only have 1396 bytes of memory free, and this machine has alot of processes running on it. What you really want to watch out for, is using alot of the swap. If your computer constantly dips heavily into the swap, it's time to add more memory. I recently increased the tasks that the above box needs to perform (mysql database for one, apache for two) so the memory requirements have no increased. Before, 64MB was more then sufficient. Now, it can handle it, but i would feel more comfortable with 128. I would suggest upgrading your box to 128MB at minimum as you are using a healthy portion of the swap, and being as how important that machine SEEMS (ie. the number of important tasks it performs) You may want to at least buy another stick of 128 as well, in case one of them goes bad, you'll have sufficient memory to run on in the mean time of a replacement. On Wed, 30 Aug 2000, Erik Peter P. Abella wrote: | Hello All, | | I had problems with the RAM (128MB SDRAM DIMM) of my server and the only | spare I had was (64MB SDRAM DIMM). | | Hear is what top says: | | 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped | CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle | Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff | Swap: 104380K av, 3128K used, 101252K free 35860K | cached | | I'm a little worried that the harddisk might thrash as there's hardly | any more memory to spare (1828K free). This server is pretty much an | "all-in-one" box running DNS, squid, postfix, apache and radius (I have | 17 modems on it's cyclades). Any recommendations on the "bare-minimum" | RAM for this configuration? The suits at our purchasing division are | "stiff" at best so when I make the requesition for the replacement, I | need to know if I need to "demand" that they "immediately" cough-up the | 128mb (or more). | | | Thanks in advance, | | | Erik | | | -- | To UNSUBSCRIBE, email to [EMAIL PROTECTED] | with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] | | -- ___ _ __ _ __ /___ ___ /__ John Gonzalez/Net.Tech __ __ \ __ \ __/_ __ `__ \/ __ /_ ___/ MDC Computers/netMDC! _ / / / `__/ /_ / / / / / / /_/ / / /__ (505)439-0200/fax-437-3052 /_/ /_/\___/\__/ /_/ /_/ /_/\__,_/ \___/ http://www.netmdc.com [-[system info]---] 1:50pm up 110 days, 19:53, 4 users, load average: 0.10, 0.19, 0.37 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
what is sufficient free memory?
Hello All, I had problems with the RAM (128MB SDRAM DIMM) of my server and the only spare I had was (64MB SDRAM DIMM). Hear is what top says: 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff Swap: 104380K av, 3128K used, 101252K free 35860K cached I'm a little worried that the harddisk might thrash as there's hardly any more memory to spare (1828K free). This server is pretty much an all-in-one box running DNS, squid, postfix, apache and radius (I have 17 modems on it's cyclades). Any recommendations on the bare-minimum RAM for this configuration? The suits at our purchasing division are stiff at best so when I make the requesition for the replacement, I need to know if I need to demand that they immediately cough-up the 128mb (or more). Thanks in advance, Erik
what is sufficient free memory?
Your biggest potential hog is squid. It maintains data structures in memory and their size grows with your cache size. If anything causes trashing that'll be it. The squid FAQ's give some back-of-envelope calculations for this AFAIK. cheers, BM
Re: what is sufficient free memory?
On Wed, 30 Aug 2000, Erik Peter P. Abella wrote: 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff Swap: 104380K av, 3128K used, 101252K free 35860K cached I'm a little worried that the harddisk might thrash as there's hardly any more memory to spare (1828K free). This server is pretty much an of that 61296 used k, 35860k is cache. filesystem cache. things happened so that linux uses the memory if it has. would it make any sense having unused memory ? ok, it's cheap these days, but not _that_ cheap... -- [-] ``And there are plenty of other innovative pieces of software such as Napster and ICQ.'' -- comment on ``Systems Software Research is Irrelevant'' at http://freshmeat.net/news/2000/08/05/965534399.html
Re: what is sufficient free memory?
Erik, linux will always use almost 100% of the memory (unless you have a BUTTLOAD of extra (ie. 512MB RAM)) for buffers and things like that. For example: skank:~# free total used free sharedbuffers cached Mem: 62956 61460 1496 15432 2064 12864 -/+ buffers/cache: 46532 16424 Swap: 102780 15476 87304 I only have 1396 bytes of memory free, and this machine has alot of processes running on it. What you really want to watch out for, is using alot of the swap. If your computer constantly dips heavily into the swap, it's time to add more memory. I recently increased the tasks that the above box needs to perform (mysql database for one, apache for two) so the memory requirements have no increased. Before, 64MB was more then sufficient. Now, it can handle it, but i would feel more comfortable with 128. I would suggest upgrading your box to 128MB at minimum as you are using a healthy portion of the swap, and being as how important that machine SEEMS (ie. the number of important tasks it performs) You may want to at least buy another stick of 128 as well, in case one of them goes bad, you'll have sufficient memory to run on in the mean time of a replacement. On Wed, 30 Aug 2000, Erik Peter P. Abella wrote: | Hello All, | | I had problems with the RAM (128MB SDRAM DIMM) of my server and the only | spare I had was (64MB SDRAM DIMM). | | Hear is what top says: | | 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped | CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle | Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff | Swap: 104380K av, 3128K used, 101252K free 35860K | cached | | I'm a little worried that the harddisk might thrash as there's hardly | any more memory to spare (1828K free). This server is pretty much an | all-in-one box running DNS, squid, postfix, apache and radius (I have | 17 modems on it's cyclades). Any recommendations on the bare-minimum | RAM for this configuration? The suits at our purchasing division are | stiff at best so when I make the requesition for the replacement, I | need to know if I need to demand that they immediately cough-up the | 128mb (or more). | | | Thanks in advance, | | | Erik | | | -- | To UNSUBSCRIBE, email to [EMAIL PROTECTED] | with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED] | | -- ___ _ __ _ __ /___ ___ /__ John Gonzalez/Net.Tech __ __ \ __ \ __/_ __ `__ \/ __ /_ ___/ MDC Computers/netMDC! _ / / / `__/ /_ / / / / / / /_/ / / /__ (505)439-0200/fax-437-3052 /_/ /_/\___/\__/ /_/ /_/ /_/\__,_/ \___/ http://www.netmdc.com [-[system info]---] 1:50pm up 110 days, 19:53, 4 users, load average: 0.10, 0.19, 0.37
Re: what is sufficient free memory?
On Tue, 29 Aug 2000, Tamas TEVESZ wrote: On Wed, 30 Aug 2000, Erik Peter P. Abella wrote: 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 61296K used, 1828K free, 36880K shrd, 7712K buff Swap: 104380K av, 3128K used, 101252K free 35860K cached of that 61296 used k, 35860k is cache. filesystem cache. things happened so that linux uses the memory if it has. would it make any sense having unused memory ? ok, it's cheap these days, but not _that_ cheap... Why not that cheap? Less than half of his ram is being used for actual needed data. The rest is either free, in cache or in buffers which means the memory isn't even close to being stressed on the system. The 3MB in swap is just crap the system doesn't mind not having ;) I don't think the memory problem is as bad as only 1.8Mb free. -Nathan
Re: what is sufficient free memory?
Not to mention that unless you are having MILD traffic through the squid box, you probably want a box dedicated to just that. On Tue, 29 Aug 2000, Bulent Murtezaoglu wrote: | | Your biggest potential hog is squid. It maintains data structures in | memory and their size grows with your cache size. If anything causes | trashing that'll be it. The squid FAQ's give some back-of-envelope | calculations for this AFAIK. | | cheers, | | BM -- ___ _ __ _ __ /___ ___ /__ John Gonzalez/Net.Tech __ __ \ __ \ __/_ __ `__ \/ __ /_ ___/ MDC Computers/netMDC! _ / / / `__/ /_ / / / / / / /_/ / / /__ (505)439-0200/fax-437-3052 /_/ /_/\___/\__/ /_/ /_/ /_/\__,_/ \___/ http://www.netmdc.com [-[system info]---] 2:00pm up 110 days, 20:03, 4 users, load average: 0.04, 0.09, 0.23
Re: what is sufficient free memory?
On Tue, 29 Aug 2000, Nathan wrote: Why not that cheap? Less than half of his ram is being used for actual needed data. The rest is either free, in cache or in buffers which means the memory isn't even close to being stressed on the system. The 3MB in that's exactly what i'm talking about. the rest is being used as cache, just because it's there, and once it's there and it's not needed for ``real'' data storage, it's being used as cache. nothing's cheap enough just to lay around unused ;) -- [-] ``And there are plenty of other innovative pieces of software such as Napster and ICQ.'' -- comment on ``Systems Software Research is Irrelevant'' at http://freshmeat.net/news/2000/08/05/965534399.html
Re: what is sufficient free memory?
Hello All, Thanks for all the reponses. From most of the replies, can I gather that I'll have to observe my how much is being swapped to determine whether I should immediately up the RAM back to 128MB? (and pester the tight-wad suits who'll approve the requesition) To paint a better picture, here's an entire top screen: 70 processes: 69 sleeping, 1 running, 0 zombie, 0 stopped CPU states: 0.1% user, 0.7% system, 0.0% nice, 99.0% idle Mem: 63124K av, 60764K used, 2360K free, 38700K shrd, 32216K buff Swap: 104380K av, 3572K used, 100808K free 7772K cached PID USER PRI NI SIZE RSS SHARE STAT LIB %CPU %MEM TIME COMMAND 1047 beyonder 10 0 1032 1032 820 R 0 0.7 1.6 0:00 top 717 root 1 0 1340 1288 1040 S 0 0.1 2.0 0:01 sshd 1 root 0 0 460 460 388 S 0 0.0 0.7 0:06 init 2 root 0 0 00 0 SW 0 0.0 0.0 0:00 kflushd 3 root 0 0 00 0 SW 0 0.0 0.0 0:00 kupdate 4 root 0 0 00 0 SW 0 0.0 0.0 0:00 kpiod 5 root 0 0 00 0 SW 0 0.0 0.0 0:00 kswapd 6 root -20 -20 00 0 SW 0 0.0 0.0 0:00 mdrecoveryd 297 root 1 0 480 472 388 S 0 0.0 0.7 0:00 syslogd 308 root 0 0 684 672 316 S 0 0.0 1.0 0:00 klogd 324 root 1 0 548 548 480 S 0 0.0 0.8 0:00 crond 340 root 15 0 472 468 392 S 0 0.0 0.7 0:00 inetd 356 root 0 0 1556 1244 596 S 0 0.0 1.9 0:00 named 366 root 0 0 772 700 604 S 0 0.0 1.1 0:01 sshd 394 root 0 0 516 508 412 S 0 0.0 0.8 0:00 automount 452 root 2 0 688 688 548 S 0 0.0 1.0 0:00 master 458 postfix0 0 812 812 648 S 0 0.0 1.2 0:00 qmgr 470 root 0 0 400 384 324 S 0 0.0 0.6 0:00 gpm 486 root 0 0 1368 1364 1288 S 0 0.0 2.1 0:00 httpd 490 nobody 0 0 1220 1172 1044 S 0 0.0 1.8 0:00 httpd 491 nobody 0 0 1224 1224 1096 S 0 0.0 1.9 0:00 httpd 492 nobody 0 0 964 964 872 S 0 0.0 1.5 0:00 httpd 493 nobody 0 0 964 964 872 S 0 0.0 1.5 0:00 httpd 494 nobody 0 0 1220 1220 1096 S 0 0.0 1.9 0:00 httpd 495 nobody 0 0 1268 1268 1120 S 0 0.0 2.0 0:00 httpd The stats on the swapping have been constant for the past hour or so, but notable too is that it's 4am here in the Philippines and there aren't any subscribers who've dialed in and engaged squid as they surf. I guess I'll be able to get a better idea later on when my subscribers start pouring in. Mabuhay kayong lahat at debian! (long live you all and debian) Erik
Re: what is sufficient free memory?
Thanks for all the reponses. From most of the replies, can I gather that I'll have to observe my how much is being swapped to determine whether I should immediately up the RAM back to 128MB? (and pester the tight-wad suits who'll approve the requesition) Why wait? Run the command vmstat, and observe how much is paged in /out, what is the scan rate? That indicates how hard the page stealer is looking for pages it can free off. vmstat 10 is usually a goodish, number but if you can run it a long time, longer sample times is useful. If you still have the 128MB in the machine, you could force Linux to ignore it, using a boot parameter. With lilo, that would mean an append line with 'mem=64M' in it, or enter it at the lilo boot prompt. boot: linux mem=64M That way you can actually trial your system out, at the cost of a reboot, to see the affect. With squid, you probably want to lower the mem cache down to about 1/4 of physical RAM, if it's higher than the default. Depending on usage perhaps less than 16MB would be a waste of RAM, your call! If the suits don't blink, then perhaps you could investigate interleaving swap over a number of disk partions, by using mkswap, and swap entries in fstab all set with a priority=5, instead of the defaults which don't interleave. Rob
Re: what is sufficient free memory?
Hello again, Robert Davies wrote: Why wait? Run the command vmstat, and observe how much is paged in /out, what is the scan rate? That indicates how hard the page stealer is looking for pages it can free off. vmstat 10 is usually a goodish, number but if you can run it a long time, longer sample times is useful. OK, here goes: procs memoryswap io system cpu r b w swpd free buff cache si sobibo incs us sy id 0 0 0 3560 1644 31188 8608 0 0 4 1 10417 0 0 99 If you still have the 128MB in the machine, you could force Linux to ignore it, using a boot parameter. Nah, the machine won't boot unless I remove it. With squid, you probably want to lower the mem cache down to about 1/4 of physical RAM, if it's higher than the default. Depending on usage perhaps less than 16MB would be a waste of RAM, your call! presumably via /etc/squid.conf ? If the suits don't blink, then perhaps you could investigate interleaving swap over a number of disk partions, by using mkswap, and swap entries in fstab all set with a priority=5, instead of the defaults which don't interleave. We'll see, I'm still waiting for a larger barracuda. It'd be nice if I can have both in one shabbang! for now I'm fairly confident that with the adjustment of squid, my swap partition can manage until I get the 128MB. Or won't that be enough? I'll soon find out and tell everyone how it goes. Mabuhay! Erik
