AIX server problem - network connection is unstable !

UNIX AIX
21

ok - so you have some link aggregations with 100/1000 and some with 10G adapters. The 10G will almost always be faster. Considering how many 10G ports you have on your box, you may want to consider to move all of them to 10G instead? That would make tuning your network much easier.

If / when you do this, after long and exhausting RAC testing on our systems (similar hardware), we have found below network tunables to be the most beneficial for us. But be careful - do not change all of them at once - but one by one and see if your performance gets better, worse or remains the same.
You can change them via no -p -o name=value - note there is NO space before and after the equal sign in the command to change them.

hstcp = 1
lo_perf = 1
rtentry_lock_complex = 1
sack = 1
sb_max = 33554432
tcp_ephemeral_high = 65535
tcp_ephemeral_low = 32768
tcp_init_window = 16
tcp_nodelayack = 1
tcp_recvspace = 8388608
tcp_sendspace = 8388608
udp_ephemeral_high = 65535
udp_ephemeral_low = 32768
udp_recvspace = 655360
udp_sendspace = 65536

in addition, you probably want to put this into your /etc/netsvc.conf
hosts=local,bind4

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22

Thank a lot for your help. Could you show me a little bit about your system, somethings like server's system model, OS version and Oracle version, so I can see how your system is similar to ours.

Cause our system is online now, it's dangerous to change something, so we need to be sure of what to do. Thanks again:)

23

we have P8 850s, 870s and P9 950s with various amounts of memory between about 256 GB up to 4 TB memory and anywhere between 40 and 128 cpus. Not virtualized. A lot less adapters (usually 4 HBAs and 4 NICs - with Oracle 12c and 19 (thats at least what the DBAs tell us). We do not have GPFS but that should not make any difference for network realistically, only for IO. OS level for us is 7.2.3.3, and we have 2-node clusters.

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24

We have solved this :). We did nothing but upgraded the OS to AIX 7.1 and GPFS 4.2 as well, and everything is OK. Thank all guys for helping me a lot.

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25

Congrats and thanks for posting back your success and reasons for your success.

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