[lug] Re: help on new disk. Speed and formatting issues

[Phil Rasch]

On Fri, Nov 22, 2002 "John Hernandez" <John.Hernandez at noaa.gov> wrote
> 
> | I decided I wanted a journalled file system on most of it, so I
> | repartitioned it (three partitions sda1, sda2, sda2) with parted,
> | and formatted it with reiserfs(sda2 and sda2) and mke2fs (sda1). I am
> | not quite sure why I used an ext2 file system on sda1 but that is what
> | I chose.
> 
> 
> If desired, you can add a journal to your ext2 filesystem by using
> 'tune2fs -j /dev/sda1', then mount it as ext3.
> 

There is one thing that I dont like about ext2f filesystems. This is
the disk access that takes place every 5 seconds or so on each file
system. The incessant chirping is like chinese water torture to me. (I
am running ext3 on the internal disk on this laptop and it is bugging
me as we speak. I thought it worthwhile to try again.

> |
> | Anyway, now hdparm reports pitiful transfer rates
> | /dev/sda:
> |  Timing buffer-cache reads:  128MB in 0.9 seconds = 137.63 MB/sec
> |  Timing buffered disk reads: 64 MB in 69 seconds = 938 kB/sec
> |
> | Can anybody tell me what I have screwed up?
> 
> 
> Check to see that DMA transfers are enabled with 'hdparm -d /dev/sda'.
> ~ Are you sure there is no disk activity during your test?
> 

I dont think you can set the DMA mode on disks driven through the
SCSI interface. I tried last night. There is no other disk
activity. The OS is running of the internal disk (/dev/hda), and I
can watch the access light when I start the test. 

Any other suggestions are appreciated.

Phil

 -- 
 Phil Rasch, Climate Modeling Section, National Center for Atmospheric Research
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