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* Re: ide drives performance issues, maybe related with buffer cache.
@ 2003-08-15 15:39 John Newbie
  2003-08-15 18:31 ` insecure
  0 siblings, 1 reply; 6+ messages in thread
From: John Newbie @ 2003-08-15 15:39 UTC (permalink / raw)
  To: vda; +Cc: linux-kernel





> > So question is : why when i am copying file from one HD to another (for
> > simplicity from /hda to /hdb)
> > the speed fall down ? Starting from about 27-30 MB/s (drives are in 
>UDMA-4,
> > hdparm -X68) it drops
> > down to 11-12 MB/s after 4-5s. In *indows transfer rate is almost 
>constant
> > and about 20-22 MB/s (same hardware). Why the h#ll we suck?
> > I feel that it's due to buffer cache, because when you use sync (while
> > copying) transfer rate is so small or even 0.
> > Drives are tuned with hdparm to highest transfer rates, readahead, 
>multiple
> > sector count (hdparm
> > for details).
> > Tried different filesystems, from classic ext2/3 to modern xfs/reiserfs. 
>The
> > same results.
> > Pure kernel from kernel.org (2.4.{19,20,21}), vendors kernels - all the

>How do you copy files? cp? dd? Midnight Commander? ;)
>Does it happen with SCSI?
>--
>vda

I've used cp & Midnight Commander (mc). Also when someone uploads big file 
on server through
samba, speed sometimes fall down to zero.

Have no idea about scsi, drives are IDE.

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^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: ide drives performance issues, maybe related with buffer cache.
@ 2003-08-16 13:11 John Newbie
  0 siblings, 0 replies; 6+ messages in thread
From: John Newbie @ 2003-08-16 13:11 UTC (permalink / raw)
  To: taz-007; +Cc: linux-kernel

>From: "T'aZ" <taz-007@skynet.be>
>To: "John Newbie" <john_r_newbie@hotmail.com>
>Subject: Re: ide drives performance issues, maybe related with buffer 
>cache.
>Date: Sat, 16 Aug 2003 15:01:33 +0200

>RTFM , and STOP SPAMMING

I've read them, see my previous posts. If you have nothing to say, better 
stay silent.
Ok, have a look at 2.6-test2, the same picture, slightly faster, though.
And 2.6 by default set unmaskirq to 1.
IO is really bursty (see post by insecure) opposite to `enemy I`.

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^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: ide drives performance issues, maybe related with buffer cache.
@ 2003-08-16 12:35 John Newbie
  2003-08-16 16:58 ` Alan Cox
  0 siblings, 1 reply; 6+ messages in thread
From: John Newbie @ 2003-08-16 12:35 UTC (permalink / raw)
  To: Anthony.Truong; +Cc: linux-kernel, vda

Drives were on different ide channels, but it makes no difference, even when 
they were on the
same channel.
In f##king windows copying is smooth (& faster then in Linux) in both cases.

Ok, guys you may close your eyes to such a problems with end users,
but in this way you never win desktop positions.

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^ permalink raw reply	[flat|nested] 6+ messages in thread
* ide drives performance issues, maybe related with buffer cache.
@ 2003-08-14  0:24 John Newbie
  0 siblings, 0 replies; 6+ messages in thread
From: John Newbie @ 2003-08-14  0:24 UTC (permalink / raw)
  To: linux-kernel

Hi guys!

Sorry for my post, but i didnt recieve answer on it after some googling & 
posting to local Linux Users Group, and i am confident that it is related 
with kernel.
I am using linux quite long, tried (&tired of) many FS's on different 
hardware, and think this behavior is common.
So question is : why when i am copying file from one HD to another (for 
simplicity from /hda to /hdb)
the speed fall down ? Starting from about 27-30 MB/s (drives are in UDMA-4, 
hdparm -X68) it drops
down to 11-12 MB/s after 4-5s. In *indows transfer rate is almost constant 
and about 20-22 MB/s (same hardware). Why the h#ll we suck?
I feel that it's due to buffer cache, because when you use sync (while 
copying) transfer rate is so small or even 0.
Drives are tuned with hdparm to highest transfer rates, readahead, multiple 
sector count (hdparm
for details).
Tried different filesystems, from classic ext2/3 to modern xfs/reiserfs. The 
same results.
Pure kernel from kernel.org (2.4.{19,20,21}), vendors kernels - all the 
same.
Doing experiments with 'sysctl -a |grep vm' values didnt resolve the 
problem.
This behavior is general, i think.
And, damn, this is very annoying for end users, for example when copying 
large files (movies,iso's).
Beyond any doubt this is very bad for IDE based file servers.

So please help me, and sorry if this post is offtopic.

==
Linux needs grouppies !
(inspired by Almost Famous & recent akpm interview)

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^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2003-08-16 16:58 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2003-08-15 15:39 ide drives performance issues, maybe related with buffer cache John Newbie
2003-08-15 18:31 ` insecure
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2003-08-16 13:11 John Newbie
2003-08-16 12:35 John Newbie
2003-08-16 16:58 ` Alan Cox
2003-08-14  0:24 John Newbie

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