Dimensioning of the SWAP space

Help with issues regarding installation of Debian
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trinidad
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Re: Dimensioning of the SWAP space

#41 Post by trinidad »

Never have had issue with cosmic rays!
God I hate those damn things!

TC
You can't believe your eyes if your imagination is out of focus.

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MicroScreen
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Re: Dimensioning of the SWAP space

#42 Post by MicroScreen »

CwF wrote:Never have had issue with cosmic rays!
Just wonderful, that's one of the few things that I hadn't considered until now. :lol:
I just hope that you won't experience any unpleasant surprises with neutrinos either. :D

@trinidad
Are there any comparative figures on data loss/errors with zramswap to alternatively using specifically targeted disk swap partitions?
Compression caching ... is still compression caching.
Well, nobody should claim that this is the ideal solution for every case, I would even vehemently reject it on old machines with extremely little space in RAM. The conventional setup of swap partitions on hard drives certainly still has some permission, but not always. However, the real issue here is still the dimensioning of an adequate solution, no matter what it looks like in the end. That means finding the optimal performance and data security through the most suitable individual solution.

Accordingly, the essential procedure is:
  1. 1. Installation according to recommended empirical values* as a starting point,
    2. Measurement and observation of the outsourcing behaviour,
    3. Adjustment and redimensioning of the swap space as required.
* David Both is of course only one of many who bring their experiences to a short denominator :!:
"Move forward and do what you think is best. If you make a mistake, you’ll learn something. But don't make the same mistake twice." - Akio Morita

LE_746F6D617A7A69
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Re: Dimensioning of the SWAP space

#43 Post by LE_746F6D617A7A69 »

CwF wrote:Well LE, I did give real examples and did say it's 'observational'. There's nothing theoretical about it. I've tested zramswap to lock, it works and manages better than nothing. I don't notice its operation (...)
What I've said, is that having mulicore CPUs *DOES NOT* improve the performance in case of compressed swap memory - this is technically impossible, as explained earlier, so we have a misunderstanding here..
Definitely, in most (but not all) cases compressed swap memory is faster than HDD-based swap, and in case of SSD it depends on quality and age of that SSD (BTW, I just can't wait for PLC SSDs - they will be slowing down dramatically within a month).

Another thing is, that Your 'observations' are subjective - f.e. what is the delay of switching between two desktop applications - is it 200ms or 10ms? - have You measured this?
Of course, You didn't - but such apparently "small" delays are killing the servers and time-critical applications.

On desktop:
Try to launch 2 huge applications for test - the easiest (but not very accurate) way to test this, is to create 2 virtual machines, which are using 2 times more memory than the host can offer - then You will at least start to see the problem.
Bill Gates: "(...) In my case, I went to the garbage cans at the Computer Science Center and I fished out listings of their operating system."
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MicroScreen
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Re: Dimensioning of the SWAP space

#44 Post by MicroScreen »

@ all of you:
ignore LE_746F6D617A7A69, he isn't able to adhere to the given topic or to contribute something constructive here!
His rubbish isn't worth looking into. The topic here is: Dimensioning of the SWAP space and not which solution is the "best" in each case. :roll:

There is enough reading material in the form of literature and also online that covers instruction-level parallelism and task parallelism. The hardware-specific facts are also taken into account here, such as the L1 and L2 CPU cashes, the number and size of which play an extremely important role here. So it always depends on the respective kernel architecture and the software used, how efficiently these options are used.

Nothing is impossible :!:
"Move forward and do what you think is best. If you make a mistake, you’ll learn something. But don't make the same mistake twice." - Akio Morita

LE_746F6D617A7A69
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Re: Dimensioning of the SWAP space

#45 Post by LE_746F6D617A7A69 »

MicroScreen wrote:@ all of you:
ignore LE_746F6D617A7A69, he isn't able to adhere to the given topic or to contribute something constructive here!
His rubbish isn't worth looking into. The topic here is: Dimensioning of the SWAP space and not which solution is the "best" in each case. :roll:
It's not Me who have started a sub-thread about compressed swap - apparently You have a serious problem with identifying who are You talking too... :lol:
MicroScreen wrote: There is enough reading material in the form of literature and also online that covers instruction-level parallelism and task parallelism. The hardware-specific facts are also taken into account here, such as the L1 and L2 CPU cashes, the number and size of which play an extremely important role here. So it always depends on the respective kernel architecture and the software used, how efficiently these options are used.
Better read that material instead of polluting this forums with your worthless posts.
Bill Gates: "(...) In my case, I went to the garbage cans at the Computer Science Center and I fished out listings of their operating system."
The_full_story and Nothing_have_changed

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4D696B65
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Re: Dimensioning of the SWAP space

#46 Post by 4D696B65 »

This thread has reduced to personal attacks therefore will be locked.

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