list node directory信息来自哪里

Your second question is related to the concept of
local db dir v.s. system db dir
They do have subtle difference收起

Hope the example will be helpful for you to understand when the sqlnodir being created;

[db2inst2@q2 sqllib]$ db2 list node directory
SQL1027N  The node directory cannot be found.
[db2inst2@q2 sqllib]$ ls ~/sqllib | grep dir
sqldbdir
[db2inst2@q2 sqllib]$ db2 catalog tcpip node q1 remote q1 server 50000
DB20000I  The CATALOG TCPIP NODE command completed successfully.
DB21056W  Directory changes may not be effective until the directory cache is
refreshed.
[db2inst2@q2 sqllib]$ ls ~/sqllib | grep dir
sqldbdir
sqlnodir
[db2inst2@q2 sqllib]$ db2 list node directory

Node Directory

Number of entries in the directory = 1

Node 1 entry:

Node name                      = Q1
Comment                        =
Directory entry type           = LOCAL
Protocol                       = TCPIP
Hostname                       = q1
Service name                   = 50000收起