[CentOS] slow responding firewall server

[Bryan J. Smith]

Peter Farrow <peter at farrows.org> wrote:
> [root@ ~]# hdparm -t /dev/hdb
> /dev/hdb:
>  Timing buffered disk reads:   62 MB in  3.07 seconds = 
> 20.17 MB/sec
> [root@ ~]# hdparm -t /dev/hda
> /dev/hda:
>  Timing buffered disk reads:   62 MB in  3.02 seconds = 
> 20.51 MB/sec

Ouch!  They are on the same channel!  Furthermore, you're
only getting the cache speed.  Try "-Tt" instead.  And try
running those 2 commands simultaneously!  You're going to see
more than a 50% drop (more like an 80%!).

>  UDMA modes: udma0 udma1 *udma2 udma3 udma4 udma5
>  UDMA modes: udma0 udma1 *udma2 udma3 udma4 udma5

Ultra DMA mode 2 (33MHz) is a good sign.

> I'm running software RAID and they are both on one IDE
> controller, but this is because the installer detects
> the drive geometry differently for each if they are on
> separate controller,

If it's Award BIOS, then set the geometry to "LBA" in the
BIOS.

Furthermore, _regardless_ of what the BIOS says, once you
partition with LBA, if you move it to another controller, the
partition table will _still_ be LBA when Linux loads the
partitions.

> which would be the best option, but as I am doing mirroring
I
> want the geometry the same. 

The geometry is _already_ the same once the partition table
has been created.  Linux _ignores_ the BIOS' geometry if it
was partitioned differently.

> Furthermore no amount of changing in the BIOS affects the
> detected geometry by Anaconda.  I've seen this quite a lot
on
> Compaqs.

Oh, a Compaq.  Yeah, broken BIOS.

But _regardless_, you've already got the correct geometry. 
You can now move channels, Linux will read the partition
table and use its geometry -- not what the BIOS says.

ATA DMA was _never_ designed for master/slave, that's an old
EIDE PIO configuration.  Drives only allow it to be
compatible, but it's not recommended at all.


-- 
Bryan J. Smith                | Sent from Yahoo Mail
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