Strange multiple hard disk io activity

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Strange multiple hard disk io activity

Postby nordle » Sun Jul 23, 2006 2:45 pm

I have two disks on primary controller, PATA, master+slave by jumper.

I'm in the process of copying 10GB of opensuse goodness from hdb to a samba share on another machine via konqueror's url smb://servername/sharename/dir

Konq has two tabs, local tree and smb tree, and I just did a right click copy and paste.

What is strange, I noticed that gkrellm was showing 15MB/sec throughput on both hdb and 12MB/sec on hda (both drives on original machine).
If this is true, then its a bizarre waste of power, resources, time etc I mean, does the data seriously have to go from hdb to hda then to the remote server, that seems very odd.

Is this real? How can I check that this is truly happening and its not some weird little bug in gkrellm?

If its real, does anyone know if its supposed to be like that or could it be:
- Hardware bug (mobo's disk controller being weird)
- KDE bug
- samba bug
- kernel bug
etc

Thanks for any suggestions.
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RE: Strange multiple hard disk io activity

Postby wyliecoyoteuk » Sun Jul 23, 2006 6:15 pm

Depends on how your PC (and NIC, and Samba) is setup, there could be temporary buffer somewhere on hda
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RE: Strange multiple hard disk io activity

Postby ollie » Tue Jul 25, 2006 4:57 am

Remember Konqueror is running from hda, as is the graphics display drivers, everytime you do something it has to be processed by an application. Also, is your swap file on hda? If your RAM is being pushed into swap file space whilst files are being loaded and moved you will have disk activity.
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RE: Strange multiple hard disk io activity

Postby nordle » Tue Jul 25, 2006 3:29 pm

This machines has 1GB of RAM, swap never gets used. I think what it is, is /proc I think /proc/copy_process_number/fd has the file copied and stored as it goes along, then when the process is finished its released again.

I don't think its a bug, but equally i'm not sure it makes a lot of sense.
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RE: Strange multiple hard disk io activity

Postby wyliecoyoteuk » Tue Jul 25, 2006 7:41 pm

Probably a FIFO pipe, acting as a cache for the network card.
In any transfer there is a "send" buffer on the transmitting pc, and a "receive" buffer at the other end.
The "send" buffer queues read packets for transmission, the "receive" buffer queues received packets for disk write.
Looks like /proc is where the pipe lives.

(Yes, this is a gross simplification)
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Re: RE: Strange multiple hard disk io activity

Postby nordle » Tue Jul 25, 2006 7:54 pm

wyliecoyoteuk wrote:(Yes, this is a gross simplification)


Which us grossly smple people appreciate, as its understandable :)
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