Re: Improved performance by reformatting?

Re: Improved performance by reformatting?

[Hans Reiser]

Jens Benecke wrote:

>Hi,
>
>recently I have begun to notice that my server (Duron 650, Via chipset,
>UDMA harddisks, hdparm says 30-35MB/sec on the raw device) have been
>slowing down during long copy actions. If I copy a 300MB file, e.g.
>midnight commander pauses frequently, sometimes over ten seconds, while
>the CPU Load (according to xosview) is stuck at 100%.
>
>DMA and so on is enabled on all harddisks.
>
>The file systems in question were created with early 2.4 kernels (2.4.4
>IIRC) and one of them is a LVM volume which was resized and moved
>several times until now. Would a backup & reformat & restore noticeably
>improve performance to make it worth the effort?
>
>I'm asking this because I will have the chance to do this shortly (new
>harddisks) and if it will make a difference, I will not just copy the
>stuff over, but recreate the FS.
>
>
>  
>
You need the latest bitmap.c (ask zam), and to turn off border, and turn 
on skip_busy.

If I can just get some decent benchmarks, we'll determine what options 
should be standard, and put this bitmap.c in the mainline kernel, but 
there are delays in benchmarking....

Hans

Re: Improved performance by reformatting?

[Hans Reiser]

Jens Benecke wrote:

>Hi,
>
>recently I have begun to notice that my server (Duron 650, Via chipset,
>UDMA harddisks, hdparm says 30-35MB/sec on the raw device) have been
>slowing down during long copy actions. If I copy a 300MB file, e.g.
>midnight commander pauses frequently, sometimes over ten seconds, while
>the CPU Load (according to xosview) is stuck at 100%.
>
>DMA and so on is enabled on all harddisks.
>
>The file systems in question were created with early 2.4 kernels (2.4.4
>IIRC) and one of them is a LVM volume which was resized and moved
>several times until now. Would a backup & reformat & restore noticeably
>improve performance to make it worth the effort?
>
>I'm asking this because I will have the chance to do this shortly (new
>harddisks) and if it will make a difference, I will not just copy the
>stuff over, but recreate the FS.
>
>
>  
>
using tar rather than dd to copy things will improve performance.  The 
repacker is scheduled for v4.1....