Low bitrate when writing from /dev/urandom to /dev/null The Next CEO of Stack OverflowWhat...
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Low bitrate when writing from /dev/urandom to /dev/null
The Next CEO of Stack OverflowWhat prevents rm /dev/null?How to dump data to DVD when the disk space reach 80% on RAID 1, and clean the dumped space from disk after burnThe 'real', 'user' and 'sys' description from time(1) differ when they shouldn't?Why is my /dev/random so slow when using dd?Does dd care when cloning from smaller hdd to bigger hdd?Can dd copy raw data from hard drives when operating system cannot recognize file system of partitions of hard disks?dd from /dev/zero to /dev/sda does not overwrite the whole diskRecovering data from a hard drive which disappears from /dev upon reading data in a bad blockSecurely wiping a drive with DD, /dev/zero or /dev/urandom?dd read into /dev/null, page cache
now for something completely different. I've got a Mac server and I got to continuously dd-write from /dev/urandom to /dev/null, efficiently. And now the data transfer speed is only about 11Mb/s. This feels wrong for me and I would like to increase the speed.
What should I check first?
Is it slow randomize algorithm, maybe some features are not supported by my CPU, or is it the kernel dropping the data to /dev/null too much slowly? I could use /dev/random instead, but its deprecated and does not guarantee sequence randomness.
Maybe I should rebuild the kernel tweaking some features? Oh I know, that's Mac and for sure I cannot rebuild the kernel... Will freebsd write to /dev/null faster?
freebsd dd
asked 3 hours ago
Dodger.elfDodger.elf
1
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Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
now for something completely different. I've got a Mac server and I got to continuously dd-write from /dev/urandom to /dev/null, efficiently. And now the data transfer speed is only about 11Mb/s. This feels wrong for me and I would like to increase the speed.
What should I check first?
Is it slow randomize algorithm, maybe some features are not supported by my CPU, or is it the kernel dropping the data to /dev/null too much slowly? I could use /dev/random instead, but its deprecated and does not guarantee sequence randomness.
Maybe I should rebuild the kernel tweaking some features? Oh I know, that's Mac and for sure I cannot rebuild the kernel... Will freebsd write to /dev/null faster?
freebsd dd
asked 3 hours ago
Dodger.elfDodger.elf
1
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
Its not the writing to /dev/null thats the bottleneck, its.the creation of random data. How random do you need random to be?
– davidgo
3 hours ago
It must be totally random. Not having this, I will never end my Qi harmonizing experiment.
– Dodger.elf
3 hours ago
In that case, forget it. You should not even be using urandom, you should (at best) be using /dev/random as /dev/urandom is not totally random (arguably /dev/random isnt either, but its a lot better). Your understanding of /dev/random and other things is incorrect.
– davidgo
3 hours ago
add a comment |
now for something completely different. I've got a Mac server and I got to continuously dd-write from /dev/urandom to /dev/null, efficiently. And now the data transfer speed is only about 11Mb/s. This feels wrong for me and I would like to increase the speed.
What should I check first?
Is it slow randomize algorithm, maybe some features are not supported by my CPU, or is it the kernel dropping the data to /dev/null too much slowly? I could use /dev/random instead, but its deprecated and does not guarantee sequence randomness.
Maybe I should rebuild the kernel tweaking some features? Oh I know, that's Mac and for sure I cannot rebuild the kernel... Will freebsd write to /dev/null faster?
freebsd dd
asked 3 hours ago
Dodger.elfDodger.elf
1
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
now for something completely different. I've got a Mac server and I got to continuously dd-write from /dev/urandom to /dev/null, efficiently. And now the data transfer speed is only about 11Mb/s. This feels wrong for me and I would like to increase the speed.
What should I check first?
Is it slow randomize algorithm, maybe some features are not supported by my CPU, or is it the kernel dropping the data to /dev/null too much slowly? I could use /dev/random instead, but its deprecated and does not guarantee sequence randomness.
Maybe I should rebuild the kernel tweaking some features? Oh I know, that's Mac and for sure I cannot rebuild the kernel... Will freebsd write to /dev/null faster?
freebsd dd
freebsd dd
asked 3 hours ago
Dodger.elfDodger.elf
1
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 3 hours ago
Dodger.elfDodger.elf
1
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 3 hours ago
Dodger.elfDodger.elf
1
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 3 hours ago
Dodger.elfDodger.elf
1
asked 3 hours ago
Dodger.elfDodger.elf
1
1
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Dodger.elf is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
Its not the writing to /dev/null thats the bottleneck, its.the creation of random data. How random do you need random to be?
– davidgo
3 hours ago
It must be totally random. Not having this, I will never end my Qi harmonizing experiment.
– Dodger.elf
3 hours ago
In that case, forget it. You should not even be using urandom, you should (at best) be using /dev/random as /dev/urandom is not totally random (arguably /dev/random isnt either, but its a lot better). Your understanding of /dev/random and other things is incorrect.
– davidgo
3 hours ago
add a comment |
1
Its not the writing to /dev/null thats the bottleneck, its.the creation of random data. How random do you need random to be?
– davidgo
3 hours ago
It must be totally random. Not having this, I will never end my Qi harmonizing experiment.
– Dodger.elf
3 hours ago
In that case, forget it. You should not even be using urandom, you should (at best) be using /dev/random as /dev/urandom is not totally random (arguably /dev/random isnt either, but its a lot better). Your understanding of /dev/random and other things is incorrect.
– davidgo
3 hours ago
1
1
Its not the writing to /dev/null thats the bottleneck, its.the creation of random data. How random do you need random to be?
– davidgo
3 hours ago
Its not the writing to /dev/null thats the bottleneck, its.the creation of random data. How random do you need random to be?
– davidgo
3 hours ago
It must be totally random. Not having this, I will never end my Qi harmonizing experiment.
– Dodger.elf
3 hours ago
It must be totally random. Not having this, I will never end my Qi harmonizing experiment.
– Dodger.elf
3 hours ago
In that case, forget it. You should not even be using urandom, you should (at best) be using /dev/random as /dev/urandom is not totally random (arguably /dev/random isnt either, but its a lot better). Your understanding of /dev/random and other things is incorrect.
– davidgo
3 hours ago
In that case, forget it. You should not even be using urandom, you should (at best) be using /dev/random as /dev/urandom is not totally random (arguably /dev/random isnt either, but its a lot better). Your understanding of /dev/random and other things is incorrect.
– davidgo
3 hours ago
add a comment |
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1
Its not the writing to /dev/null thats the bottleneck, its.the creation of random data. How random do you need random to be?
– davidgo
3 hours ago
It must be totally random. Not having this, I will never end my Qi harmonizing experiment.
– Dodger.elf
3 hours ago
In that case, forget it. You should not even be using urandom, you should (at best) be using /dev/random as /dev/urandom is not totally random (arguably /dev/random isnt either, but its a lot better). Your understanding of /dev/random and other things is incorrect.
– davidgo
3 hours ago