I have copied over all TokuMX 1.4 data files to a fresh installed TokuMX 1.5 server, but launching the server fails with:
Fri Aug 1 09:51:04.633 [initandlisten] TokuMX starting : pid=42210 port=27017 dbpath=/data/db 64-bit host=beagle.massive-insights.com
Fri Aug 1 09:51:04.633 [initandlisten] TokuMX mongod server v1.5.0-mongodb-2.4.10, using TokuKV rev 479eed747982601fa52e4c4e4b9b4be18f58d3c1
Fri Aug 1 09:51:04.633 [initandlisten] git version: 3c686d0b09d6dfb9fd54da440247d3075fcfd0ac
Fri Aug 1 09:51:04.633 [initandlisten] build info: Linux a5f9a8a9a9af 3.11.0-20-generic #35-Ubuntu SMP Fri May 2 21:32:49 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux BOOST_LIB_VERSION=1_49
Fri Aug 1 09:51:04.633 [initandlisten] options: { config: "/etc/mongodb.conf", dbpath: "/data/db", logFlushPeriod: 300, logappend: "true", logpath: "/var/log/mongodb/mongodb.log", maxConns: 20000 }
Fri Aug 1 09:51:04.634 [initandlisten] [tokumx] startup
Cannot upgrade TokuDB version 25 database. Previous improper shutdown detected.
Fri Aug 1 09:51:04.661 [initandlisten] Assertion: 16767:Unhandled ydb error: -100011
0xb3b123 0x80c91b 0x8061f0 0x8069df 0x8071fc 0x749e7a 0x74a558 0x735caa 0x7f5a97b5ceed 0x746e79
/usr/local/bin/mongod(_ZN5mongo15printStackTraceERSo+0x23) [0xb3b123]
/usr/local/bin/mongod(_ZN5mongo7storage21MsgAssertionExceptionC2EiRKSs+0x9b) [0x80c91b]
/usr/local/bin/mongod(_ZN5mongo7storage16handle_ydb_errorEi+0x390) [0x8061f0]
/usr/local/bin/mongod(_ZN5mongo7storage22handle_ydb_error_fatalEi+0xf) [0x8069df]
/usr/local/bin/mongod(_ZN5mongo7storage7startupEPNS_16TxnCompleteHooksEPNS0_14UpdateCallbackE+0x5bc) [0x8071fc]
/usr/local/bin/mongod(_ZN5mongo14_initAndListenEi+0x34a) [0x749e7a]
/usr/local/bin/mongod(_ZN5mongo13initAndListenEi+0x18) [0x74a558]
/usr/local/bin/mongod(main+0x29a) [0x735caa]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd) [0x7f5a97b5ceed]
/usr/local/bin/mongod() [0x746e79]
Fri Aug 1 09:51:04.670 [initandlisten] fatal error 16767: Unhandled ydb error: -100011
Fri Aug 1 09:51:04.670 [initandlisten] 16767 Unhandled ydb error: -100011
Fri Aug 1 09:51:04.670 [initandlisten] Fatal Assertion 16767
0xb3b123 0x9e654c 0x806bc6 0x8071fc 0x749e7a 0x74a558 0x735caa 0x7f5a97b5ceed 0x746e79
/usr/local/bin/mongod(_ZN5mongo15printStackTraceERSo+0x23) [0xb3b123]
/usr/local/bin/mongod(_ZN5mongo13fassertFailedEi+0x4c) [0x9e654c]
/usr/local/bin/mongod(_ZN5mongo7storage22handle_ydb_error_fatalEi+0x1f6) [0x806bc6]
/usr/local/bin/mongod(_ZN5mongo7storage7startupEPNS_16TxnCompleteHooksEPNS0_14UpdateCallbackE+0x5bc) [0x8071fc]
/usr/local/bin/mongod(_ZN5mongo14_initAndListenEi+0x34a) [0x749e7a]
/usr/local/bin/mongod(_ZN5mongo13initAndListenEi+0x18) [0x74a558]
/usr/local/bin/mongod(main+0x29a) [0x735caa]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd) [0x7f5a97b5ceed]
/usr/local/bin/mongod() [0x746e79]
Fri Aug 1 09:51:04.677 [initandlisten]
How can I go about the migration path 1.4 to 1.5, and how to deal with that error above?
As the log file states, "Cannot upgrade TokuDB version 25 database. Previous improper shutdown detected."
TokuMX does not support upgrades (meaning the file format has changed) unless the files you are using from the prior version came from a cleanly shutdown TokuMX.
You need to cleanly shutdown your 1.4 server, then copy or re-use the data files with 1.5.