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u-noneinc-s
6th December 2006, 11:40 PM
I was just playin' with ksysguard and found this sensor called disk throughput. I googled it and found an explaination and even tried the example
dd if=/dev/zero of=~/Media/junk bs=4k count=125000 and got what I figure to be a good output

125000+0 records in
125000+0 records out
512000000 bytes (512 MB) copied, 15.8497 seconds, 32.3 MB/s My question is, why are there so many throughput sensors in ksysguard. I have 30 of them. 1:0 through 9:0 (including a 22:0 and 22:64)

Or perhaps a better question would be what do these numbers represent (My guess would be physical discs like hd0 hd1 (or hda1 hda2 sda1 sda2) etc but there is no mention of this in ksysguard handbook and no indication of what disk 1:0 1:1 2:0 22:0 would represent, and I can find no man or doc for throughput (even with a grep disk).

Continuing to google :D

leigh123linux
7th December 2006, 12:06 AM
I gave the command a go on a avi file , I think the result of the test is out as it is a single drive.
can you explain what the count option is for.

[leigh@localhost Barnyard]$ dd if=/dev/zero of=~/Barnyard.avi bs=4k count=125000
125000+0 records in
125000+0 records out
512000000 bytes (512 MB) copied, 3.80838 seconds, 134 MB/s


thank leigh

u-noneinc-s
7th December 2006, 12:22 AM
I gave the command a go on a avi file , I think the result of the test is out as it is a single drive.
can you explain what the count option is for. Here is the past from the page I got the example from
dd if=/dev/zero of=/playpen4/junk bs=4k count=125000

This command will create a file junk in /playpen1, writing as fast as possible 125,000 blocks of 4 KB (500 MB), and print out a report like the following one

u-noneinc-s
7th December 2006, 12:35 AM
dd if=/dev/zero of=~/Barnyard.avi bs=4k count=125000
Now this is strange. It won't let me run it on a file, only on a dir

dd: opening `/home/mark/ATHF_The_Dressing/junk': Not a directory

leigh123linux
7th December 2006, 12:36 AM
thanks for original post , It gives a higher output than the drive can physically do?

[root@localhost leigh]# dd if=/dev/zero of=/junk bs=4k count=125000
125000+0 records in
125000+0 records out
512000000 bytes (512 MB) copied, 2.14849 seconds, 238 MB/s

[root@localhost ~]# hdparm -t /dev/hdc

/dev/hdc:
Timing buffered disk reads: 142 MB in 3.03 seconds = 46.84 MB/sec
[root@localhost ~]# hdparm -t /dev/sda

/dev/sda:
Timing buffered disk reads: 204 MB in 3.01 seconds = 67.69 MB/sec
[root@localhost ~]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 180 MB in 3.02 seconds = 59.54 MB/sec
[root@localhost ~]# hdparm -t /dev/sdc

/dev/sdc:
Timing buffered disk reads: 202 MB in 3.00 seconds = 67.29 MB/sec
[root@localhost ~]#

leigh123linux
7th December 2006, 12:51 AM
Now this is strange. It won't let me run it on a file, only on a dir

I cd to the directory containing barnyard.avi

u-noneinc-s
7th December 2006, 01:13 AM
I cd to the directory containing barnyard.avi
Same here (not in my example, but I tried cd ~ then ran [CODE]dd if=/dev/zero of=~/ATHF_The_Dressing/junk bs=4k count=125000[/CODE

dd: opening `~/ATHF_The_Dressing/junk': Not a directory] I was assuming because it can't create a dir in a file???, but your command appears to have succeeded.

I missed you previous post about output being higher than the drive is capable of. Just for the hell of it, try it on a dir instead of a file

leigh123linux
7th December 2006, 01:53 AM
[root@localhost leigh]# dd if=/dev/zero of=/junk bs=4k count=125000
125000+0 records in
125000+0 records out
512000000 bytes (512 MB) copied, 2.14849 seconds, 238 MB/s

when i ran it on barnyard.avi i did not add junk to end.

dd if=/dev/zero of=~/Barnyard.avi bs=4k count=125000

u-noneinc-s
7th December 2006, 01:56 AM
when i ran it on barnyard.avi i did not add junk to end.
I Didn't notice that :rolleyes:

leigh123linux
7th December 2006, 02:12 AM
got it this is more like it , changed /dev/zero to a proper harddrive address

[root@localhost ~]# dd if=/dev/hdc of=/junk bs=4k count=125000

125000+0 records in
125000+0 records out
512000000 bytes (512 MB) copied, 19.2479 seconds, 26.6 MB/s

this was the drive containing / on a ATA133 drive

this is with a SATA drive with /home

[root@localhost ~]# dd if=/dev/sdc of=/junk bs=4k count=125000
125000+0 records in
125000+0 records out
512000000 bytes (512 MB) copied, 7.12805 seconds, 71.8 MB/s
[root@localhost ~]#

u-noneinc-s
7th December 2006, 06:42 AM
You might want to check barnyard.avi. You might just find it to be an empty file with a 512000000 count.

nick.stumpos
7th December 2006, 08:57 AM
i dont get it why are you guys just writing zeros what is this supposed to accomplish other then making a very empty file? Am i missing something?

u-noneinc-s
7th December 2006, 11:00 AM
As I said in the first post I was just curious about what disk throughput was as well as the ksysguard numbering convention (1:0, 1:1 1:10)and why I had so many and started googling.

The first thing I found was the answer about what disk throughput was along with the example command. I ran it and saw the results and deleted the /junk folder. Then leigh replied with the command run on a file and I couldn't figure out why I couldn't.

Long story short, sometimes for me it's monkee see ... monkee do. I see something I try it. That's how I figure out some of the more cryptic man pages (if I'm lucky enough that they have examples in them) ;).

I did read man dd, but except for if and of, it's way over my head. And with only one mention of zero in the man, and no "0"s in the example, I don't even know where the zeros are coming from. And even though I did notice right away it created an empty junk file, or I guess not so empty after all but full of nothing (or zeros) It didn't dawn on this CRS inflicted old brain that it's not a good idea to run it on a file).

I went to read the ATHF file for a joke sig for a message to a friend and noticed it was 500 MB of nothing and I said "Ooops" If it had been an important file I would have said worse. :D

So, can you explain 30 sensors from 1:0 to 9:0? :p I continued to google but haven't found an explaination. Guess I should try the kde-linux list.