[SOLVED] Dude necessary time to do dd if=/dev/urandom of=/dev/sdx

Paulo2 · 11-21-2017, 10:00 AM

I'm running one of the latest 55020's dusk kernels (if not the latest) for -current.
Cpu fan doesn't spin faster, I think the load is too quick.

Code:

$ uname -a
Linux paulo.bfw 4.13.12 #1 SMP Wed Nov 8 09:17:19 UTC 2017 x86_64 AMD FX-8320E Eight-Core Processor AuthenticAMD GNU/Linux
paulo@paulobash~$ time dd if=/dev/urandom of=/dev/null bs=1MB count=1000
1000+0 registros de entrada
1000+0 registros de saída
1000000000 bytes (1,0 GB, 954 MiB) copiados, 3,88638 s, 257 MB/s

real    0m3,893s
user    0m0,005s
sys     0m3,887s

I'll reboot with the -current current 4.14.0 and post the results.

edit- Same results with 4.14.0, just slightly faster: 274 MB/s in 0m3,660s

FlinchX · 11-24-2017, 05:47 AM

Quote:

Originally Posted by 273

is good reason not to have a lot of random data around since I live in one of the places where it could lead to indefinite imprisonment.

Unfortunately, if you live in such a place and become a target, the Big Brother might just put a lot of random data on your drive just for the sake of getting a reason for indefinite imprisonment.

Ontopic: with kernel 4.4.14 on Slackware64-14.2, filling a 50GB with random data on a SATA hard drive, default bs value for dd, took about 80 minutes. This thread has been an interesting read, because ahead I'll have to make a few more, bigger encrypted partitions.

brianL · 11-24-2017, 06:22 AM

My ssssssssssssssllllllllllllllloooooooooooooowwwwwwwwwwwwest machine: an Asus eee pc 1001ha (modified: 2GB RAM + SSD).

Code:

brian@slacklap:~$ uname -a
Linux slacklap 4.4.88-smp #1 SMP Thu Sep 14 15:31:55 CDT 2017 i686 Intel(R) Atom(TM) CPU N270   @ 1.60GHz GenuineIntel GNU/Linux
brian@slacklap:~$ time dd if=/dev/urandom of=/dev/null bs=1MB count=1000
1000+0 records in
1000+0 records out
1000000000 bytes (1.0 GB, 954 MiB) copied, 279.87 s, 3.6 MB/s

real	4m39.886s
user	0m0.020s
sys	4m39.482s

Remember, folks! Speed kills!

lazardo · 02-07-2018, 05:47 PM

Nice being #-2

Code:

Linux eeepc 4.1.39 #2 SMP Mon Apr 17 23:02:18 PDT 2017 x86_64 Intel(R) Atom(TM) CPU D525   @ 1.80GHz GenuineIntel GNU/Linux
time dd if=/dev/urandom of=/dev/null bs=1MB count=1000
1000+0 records in
1000+0 records out
1000000000 bytes (1.0 GB) copied, 172.109 s, 5.8 MB/s

real	2m52.112s
user	0m0.003s
sys	2m52.107s

Gordie · 02-07-2018, 07:42 PM

What happened to the OP?