Re: dump runs at ~ 4 MB pr. second using Fedora Core 2 instead of the ~ 33 MB pr. second I am used to from previous distributions !

[Kristian Elof Sørensen <elof@xxxxxxxx>]

VJ wrote:

> What are the settings of your hard disks? Try running hdparm to see and
> change. Normally using 32bit drivers and enabling DMA brings dramatic change
> in data transfer.
>  
That was my first thought too, since I had a problem with the 2.4.27 
kernel refusing to use dma for the backup disk for some bizarre reason.

However hdparm -c and -d reports that 32 bit data transfer and dma are 
being used.



> VJ
> ----- Original Message ----- 
> From: "Kristian Elof Sørensen" <elof@xxxxxxxx>
> To: <fedora-list@xxxxxxxxxx>
> Sent: Sunday, September 12, 2004 1:02 PM
> Subject: dump runs at ~ 4 MB pr. second using Fedora Core 2 instead of the ~
> 33 MB pr. second I am used to from previous distributions !
>
>
>  
>
> > Problem:
> >    dump of an entire partition on one disk to a file on an EIDE disk on
> > another controller progresses at the slooow speed of approx. 4 MB pr.
> > second
> >
> >    Using the same kernel on the same machine but with a heavily
> > upgraded Redhat 7.3 instead of Fedora Core 2, dump progressed at a rate
> > of 16-33,6 MB pr. second depending on which disk was being dumped. Write
> > speed to the disk being written to is limited to 33,6 due to long EIDE
> > cables.
> >
> >
> > Details:
> >
> >    During dump with Fedora Core 2 the system load is between 2,2 and
> > 3,2, the three dump threads are consuming 1-3% cpu and less than 2 MB of
> > memory.
> >
> >    During dump with Fedora Core 2 free reports that "buffers" is around
> > 0,75 GB and "cached" around 0,65 GB during dump. Se below for snapshots.
> >
> >
> >
> >
> >
> > System:
> >    Fedora Core 2
> >    2.6.8.1 kernel compiled for SMP
> >    Dual Athlon
> >    1,5 GB RAM
> >    1,5 GB swap space
> >
> >
> >
> > free:
> >
> >    before starting dump
> >
> > bash-2.05b# free
> >             total       used       free     shared    buffers     cached
> > Mem:       1555436     129140    1426296          0       4460      26456
> > -/+ buffers/cache:      98224    1457212
> > Swap:      1509352      92368    1416984
> >
> >
> >       while dump is running (the numbers stays pretty much the same for
> > the entire run of dump)
> >
> > bash-2.05b# free
> >             total       used       free     shared    buffers     cached
> > Mem:       1555436    1547356       8080          0     735380     629692
> > -/+ buffers/cache:     182284    1373152
> > Swap:      1509352     120756    1388596
> >
> >
> > --
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> >
> >    
>
>
>