Re: [HPDD-discuss] slow write performance on 2.4.1-RC1
On 2013-10-10, at 12:16, "Michael Bloom" <michael.bloom(a)trd2inc.com>
wrote:
I'm looking for some help to understand why write throughput in
my Lustre IB cluster is only about 50-80 MB/sec, while read performance is 5-6 GB/sec.
We've gotten multi-GB/s with 2.4, so 50 MB/s is definitely not expected.
It isn't really possible to make any sensible guesses about your performance problem
without knowing what kind of writes you are doing.
It is also possible that your underlying storage is having problems. Did you try mounting
it locally and running iozone directly?
I'm running 2.4.1-RC2-PRISTINE on my MDT and 2 OSS's. Also
using 2.4.92 on my 16 clients, 3 of which run iozone write throughput tests.
Is there any reason to be running the pre-release code on the clients? Testing is great,
and the 2.5 client should have some improved performance over 2.4, but that isn't
necessarily production ready yet.
Cheers, Andreas
I noticed a few threads in the 2.4.1 RC1 and RC2 timeframe discussing
low write performance. I noticed that curr_dirty_bytes start off at 0 at the start of the
test as one would expect. As the test proceeds, one OSS's curr_dirty_bytes stays
pegged at some huge number, implying it didn't see a commit. The other OSS's
curr_dirty_bytes varies during the test as iozone writes data that gets committed. What
can I look at to see why the commit isn't happening?
Thanks in advance,
Michael
_______________________________________________
HPDD-discuss mailing list
HPDD-discuss(a)lists.01.org
https://lists.01.org/mailman/listinfo/hpdd-discuss