Re: To swap or not to swap
On Thu, 4 Dec 2008 23:16:23 + Frank Shute <[EMAIL PROTECTED]> wrote: > The alternative to not having swap is a machine that on occasion could > run out of memory. I don't know what happens in those circumstances > but I doubt if it's pretty. FreeBSD behaves fairly nicely when it runs out of memory: when I last checked it killed off the memory hog, as one might expect. There's an argument that the memory hog might just be your important database or something and the right course of action would be to panic and make sure someone gets alerted to the fact the machine's run out of memory; however the current behaviour seems good to me. -- Bruce Cran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
On Tue, Dec 02, 2008 at 04:56:52PM +, Anthony M. Rasat wrote: > > Fellas, I need opinions. Asus Eee PC, SSD storage, 512MB RAM, with > GNOME and other desktop thingy (testing out of curiousity). > > > Question is, swap or no swap? Remember, this is SSD, it is > reasonable to have no swap. However, what if I wanted OpenOffice? > This beast is memory hog AFAIK. Thanks for opinions. > What you need to do to make an informed decision is to get the characteristics of the SSD. How many writes can each cell stand? Does it have any wear levelling firmware? I'd be tempted to have swap and if it starts to crap out, replace with bigger/better SSD which as things stand should have improved write durability. There are already (or coming out) new SSDs with improved write performance & wear levelling, which if the manufacturers are to be believed, out perform electro-mechanical HDs in durability As Wojciech says, I'd dump Gnome & use some lightweight WM like fluxbox so all your memory isn't sucked up & you start to go into swap. ie. hit swap as little as possible by your choice of softs (am glad I use LaTeX ;) The alternative to not having swap is a machine that on occasion could run out of memory. I don't know what happens in those circumstances but I doubt if it's pretty. > -- > > Regards, > Regards, -- Frank Contact info: http://www.shute.org.uk/misc/contact.html ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Swapping to MMC (Was: To swap or not to swap)
On Tue, 2 Dec 2008 22:46:40 + RW <[EMAIL PROTECTED]> wrote: > On Tue, 2 Dec 2008 20:47:26 + > "Anthony M. Rasat" <[EMAIL PROTECTED]> wrote: > > > > Pros: 1) System requires swap. Period. 2) Swap may need size in > > range between 2.17 times to 2.22 time or whatever size it need. > > This is not prohibited by Eee's SSD size (4GB btw, 701 series). > > Add what swap you need, but in my experience things get pretty slow > before you even reach 1x system memory on hard disks. AFAIK the 2x > figure is to do with saving kernel dumps, which you probably don't > want to bother with. > > > > > Cons: 1) Since SSD is manufactured have limited lifetime (around > > 100,000 times write operation or so, I read it somewhere), swapping > > to SSD is more likely not a wise thing to do. > > I don't think it's much of a problem with modern wear-levelling. > It's 100,000 writes per block with the writes being spread evenly over > the device (albeit with extra write for the wear-levelling). > > There are few writes to swap until you run low on memory, so simply > having swap wont by itself wear out the device. > > > Two against one. I concurr that swap is needed. However since SSD in > > 701 series is not removable, having a bad sector in SSD is one thing > > you don't want to have. > > I would think they have spare sectors like hard disks do. > > > > performances? And what happened if FreeBSD kernel suddenly lose its > > swap file by absent-minded human? Is it going to be just angry or > > having massive heart attack? > > > I'm not sure whether an active swap file can be deleted or not, but it > would be owned by root, so not deletable by a normal user. I suspect > that it would behave like an open file and not be genuinely deleted > until swapoff'ed. In any case it's not more of a risk than deleting > any critical file. I suspect it was more a worry about someone pulling the MMC card out of the slot; in that case I think FreeBSD would panic rather quickly! Another thing to consider is that the bus the MMC sits on is probably somewhat slower than the bus the SSD is on, so any swapping is going to slow the system down even more than usual. -- Bruce Cran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Swapping to MMC (Was: To swap or not to swap)
On Tue, 2 Dec 2008 20:47:26 + "Anthony M. Rasat" <[EMAIL PROTECTED]> wrote: > Pros: 1) System requires swap. Period. 2) Swap may need size in range > between 2.17 times to 2.22 time or whatever size it need. This is not > prohibited by Eee's SSD size (4GB btw, 701 series). Add what swap you need, but in my experience things get pretty slow before you even reach 1x system memory on hard disks. AFAIK the 2x figure is to do with saving kernel dumps, which you probably don't want to bother with. > > Cons: 1) Since SSD is manufactured have limited lifetime (around > 100,000 times write operation or so, I read it somewhere), swapping > to SSD is more likely not a wise thing to do. I don't think it's much of a problem with modern wear-levelling. It's 100,000 writes per block with the writes being spread evenly over the device (albeit with extra write for the wear-levelling). There are few writes to swap until you run low on memory, so simply having swap wont by itself wear out the device. > Two against one. I concurr that swap is needed. However since SSD in > 701 series is not removable, having a bad sector in SSD is one thing > you don't want to have. I would think they have spare sectors like hard disks do. > performances? And what happened if FreeBSD kernel suddenly lose its > swap file by absent-minded human? Is it going to be just angry or > having massive heart attack? I'm not sure whether an active swap file can be deleted or not, but it would be owned by root, so not deletable by a normal user. I suspect that it would behave like an open file and not be genuinely deleted until swapoff'ed. In any case it's not more of a risk than deleting any critical file. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Swapping to MMC (Was: To swap or not to swap)
I put in your opinions in kinda pros or cons to swap in Asus Eee PC like following: Pros: 1) System requires swap. Period. it doesn't. Cons: 1) Since SSD is manufactured have limited lifetime (around 100,000 1 for MLC flash it uses. after every rewrite flash gets less reliable and keeps data for shorter time. new flash chip guarrantes 10 years data persistency using standard error correction, after 9000 rewrites it's about 1 year etc. and: SSD "disks" emulates disks instead of using flash-designed filesystem. they do LOTS of extra writes for "worn up management", mapping tables. you can safely assume 2 times more data written in reality than requested. assuming 4GB flash, 1*4GB/2=20TB of writes and flash is dead. not that much with swapping IO ranged in megabytes/s ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Swapping to MMC (Was: To swap or not to swap)
Anthony M. Rasat wrote: The rule of thumb is 2.2 times memory size. why not 2.17? Sounds good to me.Takes one more character to type... and both 2.2 and 2.17 is nonsense. the only rule is use as much as needed It's fun watching you fellas argue about 0.03 thing. I put in your opinions in kinda pros or cons to swap in Asus Eee PC like following: Pros: 1) System requires swap. Period. 2) Swap may need size in range between 2.17 times to 2.22 time or whatever size it need. This is not prohibited by Eee's SSD size (4GB btw, 701 series). Cons: 1) Since SSD is manufactured have limited lifetime (around 100,000 times write operation or so, I read it somewhere), swapping to SSD is more likely not a wise thing to do. Two against one. I concurr that swap is needed. However since SSD in 701 series is not removable, having a bad sector in SSD is one thing you don't want to have. So the questions are, because Asus Eee have MMC reader built in, is it wise to swap to MMC? Since MMC is presumably slower on write operation than SSD, isn't it become bottleneck for system performances? And what happened if FreeBSD kernel suddenly lose its swap file by absent-minded human? Is it going to be just angry or having massive heart attack? I might as well change the subject. There. FYI I asked those questions because I don't have any MMC to play with. In here 1GB MMC is about USD 5 or so. Not exactly expensive but it's late, I have to continue playing FreeBSD in Eee tommorrow. Thanks again for your opinions. i have a very small machine with ssd drive, the write issue is pretty much null on the very newest ones.. but that is neither here nor there. i'm using a high speed sd card for my swap and a couple other things, there is not drop in performance with, in fact, its reads /writes are faster than my hd. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]" ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Swapping to MMC (Was: To swap or not to swap)
>>> The rule of thumb is 2.2 times memory size. >> >> why not 2.17? > > Sounds good to me.Takes one more character to type... >and both 2.2 and 2.17 is nonsense. > >the only rule is use as much as needed It's fun watching you fellas argue about 0.03 thing. I put in your opinions in kinda pros or cons to swap in Asus Eee PC like following: Pros: 1) System requires swap. Period. 2) Swap may need size in range between 2.17 times to 2.22 time or whatever size it need. This is not prohibited by Eee's SSD size (4GB btw, 701 series). Cons: 1) Since SSD is manufactured have limited lifetime (around 100,000 times write operation or so, I read it somewhere), swapping to SSD is more likely not a wise thing to do. Two against one. I concurr that swap is needed. However since SSD in 701 series is not removable, having a bad sector in SSD is one thing you don't want to have. So the questions are, because Asus Eee have MMC reader built in, is it wise to swap to MMC? Since MMC is presumably slower on write operation than SSD, isn't it become bottleneck for system performances? And what happened if FreeBSD kernel suddenly lose its swap file by absent-minded human? Is it going to be just angry or having massive heart attack? I might as well change the subject. There. FYI I asked those questions because I don't have any MMC to play with. In here 1GB MMC is about USD 5 or so. Not exactly expensive but it's late, I have to continue playing FreeBSD in Eee tommorrow. Thanks again for your opinions. -- Regards, Anthony M. Rasat Manager - Technical, Network and Support Division PT. Jawa Pos National Network Graha Pena Jawa Pos Group Building, 5th floor Jln. Raya Kebayoran Lama 12, Jakarta Barat 12210 Indonesia.- Phone 02132185562 Phone 081574217035 Fax 02153651465 Web http://www.jpnn.com___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
Yes, have some swap. The system uses this space for more than swapping out processes. It uses it for paging and for crash dumping. The rule of thumb is 2.2 times memory size. why not 2.17? Sounds good to me.Takes one more character to type... and both 2.2 and 2.17 is nonsense. the only rule is use as much as needed ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
On Tue, Dec 02, 2008 at 08:01:22PM +0100, Wojciech Puchar wrote: > >Yes, have some swap. The system uses this space for more than swapping > >out processes. It uses it for paging and for crash dumping. The > >rule of thumb is 2.2 times memory size. > > why not 2.17? Sounds good to me.Takes one more character to type... jerry > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "[EMAIL PROTECTED]" ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
Yes, have some swap. The system uses this space for more than swapping out processes. It uses it for paging and for crash dumping. The rule of thumb is 2.2 times memory size. why not 2.17? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
On Tue, Dec 02, 2008 at 04:56:52PM +, Anthony M. Rasat wrote: > Fellas, I need opinions. Asus Eee PC, SSD storage, 512MB RAM, with GNOME > and other desktop thingy (testing out of curiousity). > > Question is, swap or no swap? Remember, this is SSD, it is reasonable > to have no swap. However, what if I wanted OpenOffice? This beast is > memory hog AFAIK. Thanks for opinions. First, please break your lines at around 70 characters. It makes it much easier to read and to respond. Yes, have some swap. The system uses this space for more than swapping out processes. It uses it for paging and for crash dumping. The rule of thumb is 2.2 times memory size. jerry > > -- > > Regards, > > Anthony M. Rasat > Manager - Technical, Network and Support Division > PT. Jawa Pos National Network > Graha Pena Jawa Pos Group Building, 5th floor > Jln. Raya Kebayoran Lama 12, Jakarta Barat 12210 > Indonesia.- > Phone 02132185562 > Phone 081574217035 > Fax 02153651465 > Web http://www.jpnn.com > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "[EMAIL PROTECTED]" ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
Anthony, SSD or no, I feel that you should treat it as you would any other hard disks doesn't wear on writes. SSD do ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
Fellas, I need opinions. Asus Eee PC, SSD storage, 512MB RAM, with GNOME and other desktop thingy (testing out of curiousity). Question is, swap or no swap? Remember, this is SSD, it is reasonable to have no swap. However, what if I wanted OpenOffice? This beast is memory hog AFAIK. Thanks for opinions. without gnome openoffice starts without problems on 256MB RAM without storage. no - don't use swap on SSD. simply remove unneeded bloat (gnome/kde etc) and 512MB will be more than plenty ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: To swap or not to swap
On Dec 2, 2008, at 11:56 AM, Anthony M. Rasat wrote: Fellas, I need opinions. Asus Eee PC, SSD storage, 512MB RAM, with GNOME and other desktop thingy (testing out of curiousity). Question is, swap or no swap? Remember, this is SSD, it is reasonable to have no swap. However, what if I wanted OpenOffice? This beast is memory hog AFAIK. Thanks for opinions. -- Anthony, SSD or no, I feel that you should treat it as you would any other hard disk. Plan for a swap space, albeit a smaller one than you would normally allocate perhaps. Cheers, Mikel ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
To swap or not to swap
Fellas, I need opinions. Asus Eee PC, SSD storage, 512MB RAM, with GNOME and other desktop thingy (testing out of curiousity). Question is, swap or no swap? Remember, this is SSD, it is reasonable to have no swap. However, what if I wanted OpenOffice? This beast is memory hog AFAIK. Thanks for opinions. -- Regards, Anthony M. Rasat Manager - Technical, Network and Support Division PT. Jawa Pos National Network Graha Pena Jawa Pos Group Building, 5th floor Jln. Raya Kebayoran Lama 12, Jakarta Barat 12210 Indonesia.- Phone 02132185562 Phone 081574217035 Fax 02153651465 Web http://www.jpnn.com ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
