[LU-11634] sanityn/test_77 improvements

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.13.0, Lustre 2.12.3
• Labels: patch
• Severity: 3
• Assignee: Vladimir Saveliev
• Reporter: Vladimir Saveliev

Description

sshd limits number of simultaneous unauthenticated connections via MaxStartups configuration parameter. By default, 10 connections are allowed.
sanityn/test_77* 's actor nrs_write_read() tries to run up to 32 do_nodes() in parallel, causing sshd to drop some of connections.

== sanityn test 77a: check FIFO NRS policy =========================================================== 22:21:58 (1541024518)
ost.OSS.ost.nrs_policies=fifo
...
fre1336: 1+0 records in
fre1336: 1+0 records out
fre1336: 1048576 bytes (1.0 MB) copied, 0.00722902 s, 145 MB/s
fre1335: ssh_exchange_identification: read: Connection reset by peer

pdsh@fre1335: fre1335: ssh exited with exit code 255
...
fre1336: 1048576 bytes (1.0 MB) copied, 0.00595128 s, 176 MB/s
 sanityn test_77a: @@@@@@ FAIL: dd at 11MB on client failed (2)