Peter Farrow peter@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.