Hi,
are there known performance issues of older clients with newer servers?
We have an Ubuntu 10.04 LTS server exporting two directories.
/a - An ext4 filesystem over a RAID 6 partition.
/b - An ext4 filesystem over LVM over DRBD over a RAID 6 partition.
The underlaying partitions have the same size and number of disks on the
same controller.
When we put the same data on both partitions and mount them on a Opensuse
11.3 box we see no difference between both mount points. It does not matter
whether one uses /a or /b. Our reference benchmark is a compile job, where
all headers are located on the NFS server. The speed is very good and as
expected.
However if we mount both exports on a RedHat 4.4 box we see that
1. the job is 3 times slower using /a
2. the job is 9 times slower using /b
The network connection and cpu of the RedHat machine are very similar to the
opensuse machine.
Is there any reason why the RedHat machine is so much slower than the
opensuse machine? Is there a reason why the /b export is three times slower
than the /a export on the redhat machine?
Christoph