[Orca-users] reads writes on a disk fileysystem basis

[Charles R. Dennett]

Blair Zajac said:
> Charles R. Dennett wrote:
>
>> Blair Zajac said:
>>
>>>Garrett, Matt M SITI-ITDIEEE wrote:
>>>
>>>
>>>>Folks
>>>>
>>>>I have been using orca for a while now.
>>>>The graphs are real good and help us manage the systems.
>>>>
>>>>One small thing.
>>>>Currently the graphs for disk's are "Disk System Wide Reads/Writes
>>>> Per Second "
>>>>Is it possible to get "Disk System per file system Reads/Writes Per
>>>> Second" ?
>>>>Thanks
>>>>Matt
>>>
>>>Hi Matt,
>>>
>>>Current versions of orcallator.se and Orca support this.  Check out:
>>>
>>>http://www.dennett.org/orca/procallator/o_gauge_disk_rd_c3_d0_per_s,o_gauge_disk_wr_c3_d0_per_s-quarterly.html
>>>
>>>Best,
>>>Blair
>>
>>
>> Please be aware my graphs are from my home Linux system and therefore
>> orcallator.se is not used.  I use the contributed procallator script
>> as my data gatherer.
>
> Thanks.  I saw the rd_c3_d0 part which I assumed was from Solaris.  I'm
> used to  seeing sda for Linux.
>
> Looks like the c3_d0 comes from this line in /proc/stat:
>
> disk_io: (3,0):(71239280,45869685,2015637314,25369595,475961144)
>
> Blair


Yes.  A while ago I dug into the code of procallator to figure out where
it got all the data.  A lot comes from /proc (hence the name.)

I have 2 IDE disks on my system.  They show up in the graphs as c3_d0 and
c3_d1.  Obviouly both are connected to the same IDE controller.  The other
IDE controller handles the CDROM and CD-RW drives.  The CD-RW drive is
treated like a SCSI drive.  There is a parameter on the kernel at boot
time that tells it to do this.  Some kind of SCSI emulation mode so the cd
writing software can deal with it I think.

I've noticed in /proc/stat right after the system boots that it will only
list the hard drives.  AS long as the CD drives are not mounted, they
won't show up there.  As soon as one is mounted, it will show up there and
stay there until the next boot.  In the graphs you'll see c11_d0.  I think
this is the CD-ROM drive.  I still need to investigate how the CD-RW drive
shows up, if it does at all.  Just haven't had the urge to dig into that
part yet.  One of these days I will play around with it.


-- 
Charlie