Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-25 Thread Goswin von Brederlow
Wouter Verhelst wou...@debian.org writes: On Sun, Jun 24, 2012 at 09:54:22PM +0200, Stephan Seitz wrote: On Sat, Jun 23, 2012 at 11:43:03PM +0200, Wouter Verhelst wrote: Meanwhile, you've got a non-FHS directory on your system that is of no immediate use. Your later suggested /store as a

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-25 Thread Goswin von Brederlow
Henrique de Moraes Holschuh h...@debian.org writes: On Sun, 24 Jun 2012, Goswin von Brederlow wrote: Henrique de Moraes Holschuh h...@debian.org writes: I've read that some SSDs really *dislike* the way Linux does TRIM batching (or doesn't :p), so yes, it may well be that on most SSDs

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-24 Thread Goswin von Brederlow
Henrique de Moraes Holschuh h...@debian.org writes: On Sun, 24 Jun 2012, Osamu Aoki wrote: On Sat, Jun 23, 2012 at 06:00:15PM +0300, Touko Korpela wrote: Tollef Fog Heen wrote: On Sun, Jun 10, 2012 at 07:46:57PM +0200, Stephan Seitz wrote: On Sun, Jun 10, 2012 at 07:12:11PM +0200,

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-24 Thread Henrique de Moraes Holschuh
On Sun, 24 Jun 2012, Goswin von Brederlow wrote: Henrique de Moraes Holschuh h...@debian.org writes: I've read that some SSDs really *dislike* the way Linux does TRIM batching (or doesn't :p), so yes, it may well be that on most SSDs regular fstrim will do much better. I'm assuming this

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-24 Thread Stephan Seitz
On Sat, Jun 23, 2012 at 11:43:03PM +0200, Wouter Verhelst wrote: On Thu, Jun 21, 2012 at 03:46:16PM +0200, Stephan Seitz wrote: So most of your Debian systems have several users working at the same time on the same system? Okay, then you have a different user base. webserver. Sorry, I

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-24 Thread Wouter Verhelst
On Sun, Jun 24, 2012 at 09:54:22PM +0200, Stephan Seitz wrote: On Sat, Jun 23, 2012 at 11:43:03PM +0200, Wouter Verhelst wrote: Meanwhile, you've got a non-FHS directory on your system that is of no immediate use. Your later suggested /store as a user /tmp replacement is a non-FHS directory

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-23 Thread Touko Korpela
Tollef Fog Heen wrote: On Sun, Jun 10, 2012 at 07:46:57PM +0200, Stephan Seitz wrote: On Sun, Jun 10, 2012 at 07:12:11PM +0200, Tollef Fog Heen wrote: ]] Stephan Seitz Will Wheezy support SSDs out of the box with all trimming functions, even if your SSD partition is using LUKS and

SSDs and discard (was: Summary: Moving /tmp to tmpfs makes it useless)

2012-06-23 Thread Stephan Seitz
On Sat, Jun 23, 2012 at 06:00:15PM +0300, Touko Korpela wrote: Tollef Fog Heen wrote: You need to enable it in all layers (fstab, crypttab, lvm.conf), yes. For now you shouldn't use discard option with SSDs, it's bad for performance. Better is to run fstrim periodically. Does this mean you

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-23 Thread Wouter Verhelst
On Thu, Jun 21, 2012 at 03:46:16PM +0200, Stephan Seitz wrote: On Thu, Jun 21, 2012 at 09:06:30AM +0200, Wouter Verhelst wrote: Maybe, but we are talking about defaults. Please correct me, but I think that most Debian systems are in some way single user systems. Not in my experience. So

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-23 Thread Osamu Aoki
On Sat, Jun 23, 2012 at 06:00:15PM +0300, Touko Korpela wrote: Tollef Fog Heen wrote: On Sun, Jun 10, 2012 at 07:46:57PM +0200, Stephan Seitz wrote: On Sun, Jun 10, 2012 at 07:12:11PM +0200, Tollef Fog Heen wrote: ]] Stephan Seitz Will Wheezy support SSDs out of the box with all

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-23 Thread Henrique de Moraes Holschuh
On Sun, 24 Jun 2012, Osamu Aoki wrote: On Sat, Jun 23, 2012 at 06:00:15PM +0300, Touko Korpela wrote: Tollef Fog Heen wrote: On Sun, Jun 10, 2012 at 07:46:57PM +0200, Stephan Seitz wrote: On Sun, Jun 10, 2012 at 07:12:11PM +0200, Tollef Fog Heen wrote: ]] Stephan Seitz Will

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-23 Thread Serge
2012/6/19 Wouter Verhelst wrote: That's not true. Only applications, that are limited by /tmp speed will become faster then. Do you know such applications? Any application which performs I/O anywhere has a chance of being limited by it. In theory. But do you know any applications actually

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-22 Thread Andrei POPESCU
On Mi, 20 iun 12, 15:18:55, Stephan Seitz wrote: Fine let’s talk. Why can’t we find a compromise? Additional to our disk /tmp we create a /ramtmp (so the name suggests that this tmp is a ramdisk) with tmpfs. This should be doable in time for Wheezy. The release notes should mention it. And

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-22 Thread Henrique de Moraes Holschuh
On Fri, 22 Jun 2012, Andrei POPESCU wrote: On Mi, 20 iun 12, 15:18:55, Stephan Seitz wrote: Fine let’s talk. Why can’t we find a compromise? Additional to our disk /tmp we create a /ramtmp (so the name suggests that this tmp is a ramdisk) with tmpfs. This should be doable in time for

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-21 Thread Wouter Verhelst
On Wed, Jun 20, 2012 at 03:18:55PM +0200, Stephan Seitz wrote: On Mon, Jun 18, 2012 at 11:42:06PM +0200, Wouter Verhelst wrote: If you write to /tmp on disk and someone or something calls sync at precisely the wrong moment, you're stuck, and your performance suffers. Not so with tmpfs.

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-21 Thread Stephan Seitz
On Thu, Jun 21, 2012 at 09:06:30AM +0200, Wouter Verhelst wrote: Maybe, but we are talking about defaults. Please correct me, but I think that most Debian systems are in some way single user systems. Not in my experience. So most of your Debian systems have several users working at the same

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-21 Thread Tomasz Rybak
Dnia 2012-06-21, czw o godzinie 09:06 +0200, Wouter Verhelst pisze: [ cut ] Yes; but if you're going to make /tmp be a separate partition, then your argument that there's more space on disk doesn't really hold anymore, either, since now /tmp is much much smaller than your disk (I've never seen

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-21 Thread Russ Allbery
Stephan Seitz stse+deb...@fsing.rootsland.net writes: On Thu, Jun 21, 2012 at 09:06:30AM +0200, Wouter Verhelst wrote: Maybe, but we are talking about defaults. Please correct me, but I think that most Debian systems are in some way single user systems. Not in my experience. So most of

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-21 Thread David Weinehall
On Wed, Jun 20, 2012 at 09:08:51PM +0200, Carlos Alberto Lopez Perez wrote: On 20/06/12 15:18, Stephan Seitz wrote: Fine let’s talk. Why can’t we find a compromise? Additional to our disk /tmp we create a /ramtmp (so the name suggests that this tmp is a ramdisk) with tmpfs. This should

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-21 Thread Stephan Seitz
On Thu, Jun 21, 2012 at 10:20:03PM +0200, David Weinehall wrote: because I think it'd be impossible to convince some people that /tmp isn't a random dumping ground for anything and everything. But what is /tmp for you? Since my first Unix experience in the 90s, /tmp was always the local disk

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-20 Thread Stephan Seitz
On Mon, Jun 18, 2012 at 11:42:06PM +0200, Wouter Verhelst wrote: If you write to /tmp on disk and someone or something calls sync at precisely the wrong moment, you're stuck, and your performance suffers. Not so with tmpfs. Maybe, but we are talking about defaults. Please correct me, but I

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-20 Thread Carlos Alberto Lopez Perez
On 20/06/12 15:18, Stephan Seitz wrote: Fine let’s talk. Why can’t we find a compromise? Additional to our disk /tmp we create a /ramtmp (so the name suggests that this tmp is a ramdisk) with tmpfs. This should be doable in time for Wheezy. The release notes should mention it. And those who

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-19 Thread Goswin von Brederlow
Wouter Verhelst wou...@debian.org writes: On Wed, Jun 13, 2012 at 04:14:52AM +0300, Serge wrote: User cannot break the system filling /tmp on disk. But he can do that if he fills /tmp on tmpfs. So /tmp on tmpfs adds one more point of failure for servers. No, that's not true. The real danger

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-18 Thread Wouter Verhelst
On Wed, Jun 13, 2012 at 04:14:52AM +0300, Serge wrote: 2012/6/10 Wouter Verhelst wrote: A lot of people (including you) said that tmpfs makes things faster. But there were no examples of popular use-cases becoming faster because of /tmp on tmpfs, so I had nothing to quote. You're not

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-18 Thread Uoti Urpala
Wouter Verhelst wrote: I don't think compiling C code has been CPU bound since before I was born (and I was born in the late 70s, so that's quite a while). C++ is a different matter, but still. Bullshit. GCC uses a lot of CPU unless you compile without optimization, and is surprisingly slow

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-13 Thread Josselin Mouette
Le mercredi 13 juin 2012 à 04:14 +0300, Serge a écrit : Yes. Everything. Every popular /tmp usage that most users expect to work is limited either by CPU (gcc compiling) or by network speed (browser or flash temporaries), or is just too fast already (bash heredoc). So moving /tmp to tmpfs

Re: Moving /tmp to tmpfs makes it useless

2012-06-13 Thread Goswin von Brederlow
Josselin Mouette j...@debian.org writes: Le jeudi 07 juin 2012 à 15:48 +0100, Ben Hutchings a écrit : There's no need to be a dick about it. Because this discussion was all about not being a dick to begin with, of course. Remind me who, in absence of consensus, explained that if tmpfs

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-13 Thread Ben Hutchings
On Wed, 2012-06-13 at 09:22 +0200, Josselin Mouette wrote: Le mercredi 13 juin 2012 à 04:14 +0300, Serge a écrit : Yes. Everything. Every popular /tmp usage that most users expect to work is limited either by CPU (gcc compiling) or by network speed (browser or flash temporaries), or is

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-12 Thread Serge
2012/6/10 Wouter Verhelst wrote: A lot of people (including you) said that tmpfs makes things faster. But there were no examples of popular use-cases becoming faster because of /tmp on tmpfs, so I had nothing to quote. You're not even trying. if tmpfs is faster than (say) ext4, then

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-11 Thread Josselin Mouette
Le dimanche 10 juin 2012 à 01:51 +0300, Serge a écrit : Some people asked for a thread summary. So here it is. /tmp on tmpfs is good quotes == No real quotes here. So much for a thread summary. -- .''`. Josselin Mouette : :' : `. `' `- -- To

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Adam Borowski
On Sun, Jun 10, 2012 at 01:51:19AM +0300, Serge wrote: Some people asked for a thread summary. So here it is. [Lots of drivel, including thoroughly debunked statements, snipped. Seriously, can't you even read what's written to you? Sorry for being angry, but there's a limit to how many times you

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Wouter Verhelst
On Sun, Jun 10, 2012 at 01:51:19AM +0300, Serge wrote: Some people asked for a thread summary. So here it is. Sorry, but this is a biased summary, and therefore useless for what it intends to be. [...] /tmp on tmpfs is good quotes == No real quotes here. Most of

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Serge
2012/6/10 Adam Borowski wrote: Some people asked for a thread summary. So here it is. Seriously, can't you even read what's written to you? Yes, I know it was a biased summary. So as yours. But there's a difference between mine and yours. Mine is based on some real-world applications, yours is

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Bjørn Mork
Serge sergem...@gmail.com writes: 2012/6/10 Adam Borowski wrote: Some people asked for a thread summary. So here it is. Seriously, can't you even read what's written to you? Yes, I know it was a biased summary. I think you might start to piss off a few people now... Look at what you are

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Serge
2012/6/10 Wouter Verhelst wrote: Sorry, but this is a biased summary, and therefore useless for what it intends to be. Yes, I know. It's biased toward the /tmp and real-world applications. /tmp on tmpfs is good quotes No real quotes here. Most of this and other threads were about why /tmp

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Uoti Urpala
Serge wrote: 2012/6/10 Adam Borowski wrote: Some people asked for a thread summary. So here it is. Seriously, can't you even read what's written to you? Yes, I know it was a biased summary. So as yours. But there's a difference between mine and yours. Mine is based on some real-world

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Stephan Seitz
On Sun, Jun 10, 2012 at 12:35:47PM +0200, Adam Borowski wrote: * Less wear of SSD drives. • Contrary to Serge's claims, SSDs are not an oddity, and it's not unlikely these will be a majority before wheezy becomes oldstable. He didn’t say they were oddities. He said you should more worry

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Serge
2012/6/10 Uoti Urpala wrote: Yes, I know it was a biased summary. So as yours. But there's a difference between mine and yours. Mine is based on some real-world applications, You've posted blatantly false claims. If you post claims like 1+1 equals 2 because the moon is made of cheese, then

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Tollef Fog Heen
]] Stephan Seitz Will Wheezy support SSDs out of the box with all trimming functions, even if your SSD partition is using LUKS and LVM? Depends on what you mean by out of the box. I suspect you still need to turn on discard support (since it has security implications). It does not require

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Stephan Seitz
On Sun, Jun 10, 2012 at 07:12:11PM +0200, Tollef Fog Heen wrote: ]] Stephan Seitz Will Wheezy support SSDs out of the box with all trimming functions, even if your SSD partition is using LUKS and LVM? Depends on what you mean by out of the box. I suspect you still need to turn on discard

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Wouter Verhelst
On Sun, Jun 10, 2012 at 06:13:24PM +0300, Serge wrote: 2012/6/10 Wouter Verhelst wrote: Sorry, but this is a biased summary, and therefore useless for what it intends to be. Yes, I know. It's biased toward the /tmp and real-world applications. /tmp on tmpfs is good quotes No real

Re: Is it me or virtualbox memory management crap? (was: Summary: Moving /tmp to tmpfs makes it useless)

2012-06-10 Thread Thomas Goirand
On 06/10/2012 11:55 PM, Stephan Seitz wrote: Well, if I start Virtual Box on my notebook (4 GB RAM), the system uses the swap partition. Frankly, I don't know what the fuck virtualbox is doing with its memory management, but I was tempted more than once to file a RC bug with a title like this

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Jon Dowland
On Sun, Jun 10, 2012 at 12:35:47PM +0200, Adam Borowski wrote: On Sun, Jun 10, 2012 at 01:51:19AM +0300, Serge wrote: Some people asked for a thread summary. So here it is. But, for the rest of us, here's a different summary. I've long thought that the wiki might be a good tool for trying to

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Philipp Kern
On Sun, Jun 10, 2012 at 07:46:57PM +0200, Stephan Seitz wrote: On Sun, Jun 10, 2012 at 07:12:11PM +0200, Tollef Fog Heen wrote: ]] Stephan Seitz Will Wheezy support SSDs out of the box with all trimming functions, even if your SSD partition is using LUKS and LVM? Depends on what you mean by

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Uoti Urpala
Serge wrote: 2012/6/10 Uoti Urpala wrote: You've posted blatantly false claims. If you post claims like 1+1 equals 2 because the moon is made of cheese, then you're a moron, even if 1+1 does equal 2. (I like this example :)) It could be, it's impossible to know everything in the world,

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Tollef Fog Heen
]] Philipp Kern On Sun, Jun 10, 2012 at 07:46:57PM +0200, Stephan Seitz wrote: On Sun, Jun 10, 2012 at 07:12:11PM +0200, Tollef Fog Heen wrote: ]] Stephan Seitz Will Wheezy support SSDs out of the box with all trimming functions, even if your SSD partition is using LUKS and LVM?

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Stephan Seitz
On Sun, Jun 10, 2012 at 10:31:21PM +0200, Tollef Fog Heen wrote: Well, nice to hear, but I thought, discard was needed in all layers, so in my example in LUKS, then in LVM and then in the filesystem. Or is his only a function you activate via hdparm? It's available in all layers, but as

Re: Is it me or virtualbox memory management crap? (was: Summary: Moving /tmp to tmpfs makes it useless)

2012-06-10 Thread Serge
2012/6/10 Thomas Goirand wrote: Let's put it this way: I can't run Virtualbox AND Firefox at the same time, or my laptop becomes unusably slow and non responsive. Do you use 2.6 kernel and have FF profile and VB images on the same ext4 partition? Can you reproduce that with 3.2 kernel? PS:

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Charles Plessy
Some people asked for a thread summary. So here it is. Seriously, can't you even read what's written to you? Yes, I know it was a biased summary. I think you might start to piss off a few people now... Look at what you are quoting above. You introduced your biased summary like this:

Re: Summary: Moving /tmp to tmpfs makes it useless

2012-06-10 Thread Serge
2012/6/10 Uoti Urpala wrote: What false claim are you talking about? The problem is that you've posted quite a few of those false claims [...] For example, the page you linked for your SSDs can take 50 years of writing before they wear out claim has a first paragraph saying durability IS

Summary: Moving /tmp to tmpfs makes it useless

2012-06-09 Thread Serge
Some people asked for a thread summary. So here it is. Contents * Short Problem Summary * My point * Initial suggestion - RAMTMP=no + d-i extension * Later suggestion - RAMTMP=auto * Other ideas * Alternatives - SSD setup - Normal - SSD setup - Paranoid * /tmp on tmpfs is good quotes

Re: Moving /tmp to tmpfs makes it useless

2012-06-07 Thread Josselin Mouette
Le mercredi 06 juin 2012 à 19:56 -0400, Joey Hess a écrit : A lot of people came down on the pro-tmpfs side in this thread. You have some good reasons to want to make it available to users. I just wanted to invite you to make it easier for users to enable tmpfs where appropriate -- d-i's

Re: Moving /tmp to tmpfs makes it useless

2012-06-07 Thread Ben Hutchings
On Thu, 2012-06-07 at 09:37 +0200, Josselin Mouette wrote: Le mercredi 06 juin 2012 à 19:56 -0400, Joey Hess a écrit : A lot of people came down on the pro-tmpfs side in this thread. You have some good reasons to want to make it available to users. I just wanted to invite you to make it

Re: Moving /tmp to tmpfs makes it useless

2012-06-07 Thread Josselin Mouette
Le jeudi 07 juin 2012 à 15:48 +0100, Ben Hutchings a écrit : There's no need to be a dick about it. Because this discussion was all about not being a dick to begin with, of course. Remind me who, in absence of consensus, explained that if tmpfs was enabled by default, he would forcefully make

Re: Moving /tmp to tmpfs makes it useless

2012-06-06 Thread Joey Hess
So RAMTMP now defaults to off. I know it can be hard to give ground on something you've invested a lot of work into, so Roger Leigh has my respect for taking this thread into consideration. A lot of people came down on the pro-tmpfs side in this thread. You have some good reasons to want to make

Re: Moving /tmp to tmpfs makes it useless

2012-06-05 Thread Goswin von Brederlow
Salvo Tomaselli tipos...@tiscali.it writes: If anyone wants to experience that then write out some GB of data over NFS. After a short while processes will hang while others keep running. True, that's what i was saying. But if there is not enough memory, it's not only one process that will

Re: Moving /tmp to tmpfs makes it useless

2012-06-05 Thread Goswin von Brederlow
Ben Hutchings b...@decadent.org.uk writes: On Fri, Jun 01, 2012 at 11:19:40PM +0200, Carlos Alberto Lopez Perez wrote: On 01/06/12 13:33, Goswin von Brederlow wrote: I don't know the ultimate reason behind this ugly behaviour of Linux when the swapping process is happening, but I know

Re: Moving /tmp to tmpfs makes it useless

2012-06-05 Thread Goswin von Brederlow
Salvo Tomaselli tipos...@tiscali.it writes: No, tmpfs will be swapped out if you don't use a file for a while but something else uses memory, including IO caching. unless too many things want to use memory, then tmpfs gives a great contribution in taking down the machine. As you pointed

Re: Moving /tmp to tmpfs makes it useless

2012-06-05 Thread Goswin von Brederlow
Uoti Urpala uoti.urp...@pp1.inet.fi writes: Goswin von Brederlow wrote: Le vendredi 25 mai 2012 à 16:01 +0300, Uoti Urpala a écrit : There is one significant difference though. When you read data back to memory from swap, the kernel does not remember that it already exists on disk;

Re: Moving /tmp to tmpfs makes it useless

2012-06-05 Thread Uoti Urpala
Goswin von Brederlow wrote: Uoti Urpala uoti.urp...@pp1.inet.fi writes: I haven't read the relevant kernel code, but that doesn't match the behavior I see. Reading a large file from tmpfs and then allocating memory results in large swap writes every time, even if the newly allocated

Re: Moving /tmp to tmpfs makes it useless

2012-06-03 Thread Joey Hess
Roger Leigh wrote: OK, some benchmarks were requested in this thread in a few places. No, a lack of premature optimisation was requested. When one is engaged in premature optimisation, one does lots of benchmarks, and finds things that seem to speed up nicely, and has many happy nice numbers

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Serge
2012/6/2 Roger Leigh wrote: These tests were all performed on current unstable using a core2 quad core system with ext4 and swap on LVM on a 1 TiB MD RAID1 PV, and Btrfs internally using RAID1 over 2 1TiB partitions. Well, not fair for btrfs, but anyway, finally, some tests! Thank you for

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Serge
2012/6/2 Carlos Alberto Lopez Perez wrote: IMHO The logical way of behaving in such situation is to slow-down the IO bandwidth of the processes that are filling the cache, by sending to sleep any process that requests more IO while the cache is full instead of trying to free RAM by swapping

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Thomas Goirand
On 06/01/2012 06:50 PM, Goswin von Brederlow wrote: There is also no problem with having large files in tmpfs. Only requirement is that you make tmpfs large enough and add enough ram and/or swap to cope with it. Well, there's the problem that it will take some memory at least. So either your

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Toni Mueller
Hi Thomas, On Sat, Jun 02, 2012 at 07:33:26PM +0800, Thomas Goirand wrote: All the complaints about /tmp as tmpfs come down to one simple issue: The size of the tmpfs isn't chosen well. It would be more constructive to find a better heuristic for the size there. No. The complain is that

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Teemu Likonen
* Toni Mueller [2012-06-02 13:46:19 +0200] wrote: My suggested fix for this problem is to install a ~/tmp upon account creation, and set the TEMP environment variable in, say, /etc/environments. That *should* fix up all cases except for rogue applications that don't honour $TEMP. We can then

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Salvo Tomaselli
that problem applies to disks as well, and especially to small / partitions, if you don't have /tmp somewhere else. But by default the installer doesn't create a small / partition, it uses all the available space. So by default just by clicking next-next, there are no such problems. Users who

Re: Moving /tmp to tmpfs makes it useless

2012-06-02 Thread Stefan Lippers-Hollmann
Hi Now lets do a benchmark on a busy system (during a kernel compile) and some memory pressure, due to building on tmpfs. While this is not directly representative for /tmp/ usage patterns, it does show what happens if /tmp/ gets full and fights against normal RAM uses. Tested on a current

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Henrique de Moraes Holschuh h...@debian.org writes: On Fri, 25 May 2012, Thomas Goirand wrote: for small files, and in that case, it's faster. In reality, it's not that much faster, thanks to Linux caching of the filesystem, Under heavy filesystem IO load, yes it is. By several orders of

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Carlos Alberto Lopez Perez clo...@igalia.com writes: On 25/05/12 12:14, Henrique de Moraes Holschuh wrote: On Fri, 25 May 2012, Thomas Goirand wrote: for small files, and in that case, it's faster. In reality, it's not that much faster, thanks to Linux caching of the filesystem, Under

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Nikolaus Rath nikol...@rath.org writes: Thomas Goirand z...@debian.org writes: On 05/25/2012 05:33 PM, Mehdi Dogguy wrote: What if we're installing Debian on a very small system, and that we need operations with big files in /tmp? Increase your swap? So, in this case, we will have the

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Vincent Danjean vdanjean...@free.fr writes: Le 25/05/2012 05:03, Russell Coker a écrit : On Fri, 25 May 2012, Serge sergem...@gmail.com wrote: Q: /tmp on tmpfs increases apps performance. A: What apps? Real apps don't write files during performance-critical operations. Even if they do,

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Salvo Tomaselli tipos...@tiscali.it writes: Because paging out a couple Gigabytes is veery different from writing a couple Gigabytes to disk, of course. Yes because writing that on disk will only block the thread performing the write, not every thread that tries to allocate memory.

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Carlos Alberto Lopez Perez clo...@igalia.com writes: On 25/05/12 12:20, Henrique de Moraes Holschuh wrote: On Fri, 25 May 2012, Salvo Tomaselli wrote: Because paging out a couple Gigabytes is veery different from writing a couple Gigabytes to disk, of course. Yes because writing that on

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Salvo Tomaselli tipos...@tiscali.it writes: So what? If you write to a normal file system, it goes into the page cache, which is pretty much the same as writing into tmpfs. tmpfs will make it stay forever in the RAM, caches are flushed to disk and their space can be used for new things.

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Goswin von Brederlow
Josselin Mouette j...@debian.org writes: Le vendredi 25 mai 2012 à 16:01 +0300, Uoti Urpala a écrit : There is one significant difference though. When you read data back to memory from swap, the kernel does not remember that it already exists on disk; when the data is evicted from memory

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Roger Leigh
On Mon, May 28, 2012 at 01:21:43PM +0800, Thomas Goirand wrote: On 05/28/2012 05:32 AM, Roger Leigh wrote: On Sun, May 27, 2012 at 10:46:27PM +0800, Thomas Goirand wrote: On 05/25/2012 07:44 PM, Roger Leigh wrote: However, the majority of software which finds the tmpfs too small has

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Roger Leigh
On Fri, May 25, 2012 at 12:44:03PM +0100, Roger Leigh wrote: On Fri, May 25, 2012 at 02:22:24AM +0300, Serge wrote: I've read across different debates about whether using tmpfs is good or bad but I could not find the most important reason, so here it is... I haven't got anything

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Salvo Tomaselli
If anyone wants to experience that then write out some GB of data over NFS. After a short while processes will hang while others keep running. True, that's what i was saying. But if there is not enough memory, it's not only one process that will hang. It's everything. So i think that adding

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Salvo Tomaselli
No, tmpfs will be swapped out if you don't use a file for a while but something else uses memory, including IO caching. unless too many things want to use memory, then tmpfs gives a great contribution in taking down the machine. As you pointed out yourself in another email, under memory

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Salvo Tomaselli
And you are not correct here. The tmpfs defaults to guaranteeing a certain fixed size being available, as I stated above. If the memory was used up by applications and data, then the system will swap, drop cached data, flush unwritten data to disc etc. in order to make room for it. You

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Serge
2012/6/1 Roger Leigh wrote: I'm certainly not averse to switching the default back, if this is the best solution at the present time for the majority of our users. If only it was the best solution... As was seen in both this an earlier discussions, there is not a clear-cut consensus

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Uoti Urpala
Goswin von Brederlow wrote: Le vendredi 25 mai 2012 à 16:01 +0300, Uoti Urpala a écrit : There is one significant difference though. When you read data back to memory from swap, the kernel does not remember that it already exists on disk; when the data is evicted from memory again, it

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Carlos Alberto Lopez Perez
On 01/06/12 13:33, Goswin von Brederlow wrote: I don't know the ultimate reason behind this ugly behaviour of Linux when the swapping process is happening, but I know this is real and it happens because I have experimented this situation myself more than a couple of times. It's a matter

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Roger Leigh
On Fri, May 25, 2012 at 02:22:24AM +0300, Serge wrote: Q: /tmp on tmpfs increases apps performance. A: What apps? Real apps don't write files during performance-critical operations. Even if they do, they write large files. And large files are written faster when they're written on real

Re: Moving /tmp to tmpfs makes it useless

2012-06-01 Thread Ben Hutchings
On Fri, Jun 01, 2012 at 11:19:40PM +0200, Carlos Alberto Lopez Perez wrote: On 01/06/12 13:33, Goswin von Brederlow wrote: I don't know the ultimate reason behind this ugly behaviour of Linux when the swapping process is happening, but I know this is real and it happens because I have

Re: Moving /tmp to tmpfs makes it useless

2012-05-30 Thread Josselin Mouette
Le samedi 26 mai 2012 à 23:02 +0200, Carlos Alberto Lopez Perez a écrit : With tmpfs on /tmp you are breaking many applications that assume that they have enough space to write on /tmp like the flash player ( see Debian bug #666096 ) or cdrecord software ( see #665634 ). Seriously, this is

Re: Moving /tmp to tmpfs makes it useless

2012-05-30 Thread Vincent Lefevre
On 2012-05-30 12:08:29 +0200, Josselin Mouette wrote: Le samedi 26 mai 2012 à 23:02 +0200, Carlos Alberto Lopez Perez a écrit : With tmpfs on /tmp you are breaking many applications that assume that they have enough space to write on /tmp like the flash player ( see Debian bug #666096 )

Re: Moving /tmp to tmpfs makes it useless

2012-05-30 Thread Bjørn Mork
Vincent Lefevre vinc...@vinc17.net writes: On 2012-05-30 12:08:29 +0200, Josselin Mouette wrote: Le samedi 26 mai 2012 à 23:02 +0200, Carlos Alberto Lopez Perez a écrit : With tmpfs on /tmp you are breaking many applications that assume that they have enough space to write on /tmp like the

Re: Moving /tmp to tmpfs makes it useless

2012-05-30 Thread Jon Dowland
On Wed, May 30, 2012 at 02:48:26PM +0200, Bjørn Mork wrote: Does that make any difference at all? If an application is unable to handle the out-of-space condition, then it will be unable to handle the out-of-space condition no matter how big the file system is. Increasing the file system

Re: Moving /tmp to tmpfs makes it useless

2012-05-30 Thread Steve Langasek
On Wed, May 30, 2012 at 02:48:26PM +0200, Bjørn Mork wrote: Vincent Lefevre vinc...@vinc17.net writes: On 2012-05-30 12:08:29 +0200, Josselin Mouette wrote: Le samedi 26 mai 2012 à 23:02 +0200, Carlos Alberto Lopez Perez a écrit : With tmpfs on /tmp you are breaking many applications

Re: Moving /tmp to tmpfs makes it useless

2012-05-29 Thread Toni Mueller
On Mon, May 28, 2012 at 08:26:52AM -0400, Weldon Goree wrote: at some point). Much better developers than me seem to have formed this opinion too (cf browsers' behavior while it waits for you to tell it what to do with an unknown content-type: it's a disk-based pipe to whatever program you

Re: Moving /tmp to tmpfs makes it useless

2012-05-28 Thread Toni Mueller
Hi, On Fri, May 25, 2012 at 02:22:24AM +0300, Serge wrote: What's a temporary file? Really, why would applications temporarily store its data in a file? They do that to *free some memory*. Placing those files back to memory renders the whole process of writing the file useless. If the files

Re: Moving /tmp to tmpfs makes it useless

2012-05-28 Thread Weldon Goree
On Mon, 28 May 2012 13:03:47 +0200 Toni Mueller t...@debian.org wrote: It's not, see below. Also, most of the time, /tmp goes into / (on smaller systems), and is thus typically *very* much limited in space. If the theory is to design for the trained chicken install (and it still is, right?),

Re: Moving /tmp to tmpfs makes it useless

2012-05-28 Thread Stephan Seitz
On Mon, May 28, 2012 at 01:21:43PM +0800, Thomas Goirand wrote: As you wrote, nothing is infinite. I don't think that /tmp is worse than /home like other said. Your /home could become full as well. Your /home could be a network share like NFS and /tmp a local partition, so you don’t want to

Re: Moving /tmp to tmpfs makes it useless

2012-05-27 Thread Adam Borowski
On Sat, May 26, 2012 at 10:59:06PM -0400, Joey Hess wrote: Adam Borowski wrote: I think that box had jfs, but other filesystems are no different: for example, ext* will fsync() during a rename() call behind your back even if you don't request it, forcing every file to hit the disk platters

Re: Moving /tmp to tmpfs makes it useless

2012-05-27 Thread Adam Borowski
On Sun, May 27, 2012 at 05:21:04AM +0300, Serge wrote: 2012/5/27 Adam Borowski wrote: I think that box had jfs, but other filesystems are no different: for example, ext* will fsync() during a rename() call behind your back even if you don't request it, forcing every file to hit the disk

Re: Moving /tmp to tmpfs makes it useless

2012-05-27 Thread Henrique de Moraes Holschuh
On Sat, 26 May 2012, Joey Hess wrote: Henrique de Moraes Holschuh wrote: In fact it is the other way. We have /var/tmp for the large file since about forever, and important platforms that have /tmp in memory since the early 2000's (Solaris) And that STILL wasn't enough for people

Re: Moving /tmp to tmpfs makes it useless

2012-05-27 Thread Henrique de Moraes Holschuh
On Sat, 26 May 2012, Carlos Alberto Lopez Perez wrote: So please, don't argue about theoretical things about virtual memory or IO schedulers. If you are a desktop Linux user, you should know how ugly the things get when the system is swapping. Mine is not that annoying, but certainly not

Re: Moving /tmp to tmpfs makes it useless

2012-05-27 Thread Thomas Goirand
On 05/27/2012 04:32 AM, Russ Allbery wrote: The root problem here is that we have multiple parameters that we want to set on temporary storage: 1. Space for dumping arbitrary files without assuming anything about the structure of the user's home directory. 2. Fast space for small

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