dd + /dev/urandom

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



OK guys, what going on here?
Why is the length of dd's output file truncated if the job is
paused and backgrounded? The problem is reproducible but the
truncated lengths differ. It doesnt happen for if=/dev/zero

Cheers,
Terry.



[root@fmtest]# uname -a
Linux fmtest.lmb.internal 2.6.11-1.35_FC3 #1 Mon Jun 13 00:52:08 EDT 2005 i686 i686 i386 GNU/Linux

[root@fmtest]# dd if=/dev/urandom of=junk100M.uran bs=1000000 count=100 
100+0 records in
100+0 records out
[root@fmtest]# ls -l junk100M.uran 
-rw-r--r--  1 root root 100000000 Aug 18 17:54 junk100M.uran



[root@fmtest]# dd if=/dev/urandom of=junk100M.uran bs=1000000 count=100 &
[1] 4516
[root@fmtest]# 100+0 records in
100+0 records out

[1]    Done                          dd if=/dev/urandom of=junk100M.uran bs=1000000 count=100
[root@fmtest]# ls -l junk100M.uran
-rw-r--r--  1 root root 100000000 Aug 18 17:54 junk100M.uran




[root@fmtest]# dd if=/dev/urandom of=junk100M.uran bs=1000000 count=100

Suspended
[root@fmtest]# bg
[1]    dd if=/dev/urandom of=junk100M.uran bs=1000000 count=100 &
[root@fmtest]# 99+1 records in
99+1 records out

[1]    Done                          dd if=/dev/urandom of=junk100M.uran bs=1000000 count=100
[root@fmtest]# ls -l junk100M.uran
-rw-r--r--  1 root root 99506220 Aug 18 17:55 junk100M.uran


[Index of Archives]     [Current Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Yosemite News]     [Yosemite Photos]     [KDE Users]     [Fedora Tools]     [Fedora Docs]

  Powered by Linux