Re: Network very very slow... was iSCSI and jumbo frames

[RVP <rvp%SDF.ORG@localhost>]

On Wed, 3 Feb 2021, BERTRAND Joël wrote:

> legendre# dd if=/dev/zero of=/opt/bacula/test.dd count=100 bs=1m
> iflag=direct oflag=creat,direct
> 100+0 records in
> 100+0 records out
> 104857600 bytes transferred in 0.315 secs (332881269 bytes/sec)

I'm thinking now that since you have 16GB RAM, 100MB maybe too
small for this test--which is how you are getting better than wire
speed on the test. That 100 MB of data is probably getting absorbed
in your local buffers somewhere. (And, I'm unsure if the `direct'
flag is useful with FFS ontop of iSCSI.)

> legendre# dd if=/dev/zero of=/opt/bacula/test.dd count=1000 bs=1m
> iflag=direct oflag=creat,direct
> 1000+0 records in
> 1000+0 records out
> 1048576000 bytes transferred in 53.515 secs (19594057 bytes/sec)

20 MB/sec may not be too shabby, I think. It's around 1/3 of what
Michael reported he gets (~68 MB/sec) with his setup.

> legendre# dd if=/dev/zero of=/opt/bacula/test.dd count=10000 bs=1m
> iflag=direct
> oflag=creat,direct
> 10000+0 records in
> 10000+0 records out
> 10485760000 bytes transferred in 1040.933 secs (10073424 bytes/sec)

I can't explain this; maybe Michael can.

> 	I have found a 4GB DDR3L. This afternoon, I will try to replace NAS memory.

Yes. Try tests 2 & 3 afterwards.

-RVP