Qdb NODE-HEALTH is RED for unclear reasons

Hi,
I was setting up a small test cluster with three qdb following the Getting Started guide, but I’m constantly seeing the node-health as ‘red’ although qdb appears to run.
This is what ‘eos daemon config qdb qdb info’ shows:

[putenv] EOS_USE_MQ_ON_QDB=1
[putenv] EOS_XROOTD=/opt/eos/xrootd/
[putenv] GEO_TAG=072::rack102::35
[putenv] INSTANCE_NAME=eosdev
[putenv] LD_LIBRARY_PATH=/opt/eos/xrootd//lib64:/opt/eos/grpc/lib64
[putenv] LD_PRELOAD=/usr/lib64/libjemalloc.so
[putenv] QDB_CLUSTER_ID=eosdev
[putenv] QDB_HOST=eos1.math.tu-berlin.de
[putenv] QDB_NODE=eos1.math.tu-berlin.de:7777
[putenv] QDB_NODES=eos1.math.tu-berlin.de:7777,eos2.math.tu-berlin.de:7777,eosfst3.math.tu-berlin.de:7777
[putenv] QDB_PATH=/var/lib/qdb
[putenv] QDB_PORT=7777
[putenv] SERVER_HOST=eos1.math.tu-berlin.de
 1) TERM 1
 2) LOG-START 0
 3) LOG-SIZE 67
 4) LEADER eos1.math.tu-berlin.de:7777
 5) CLUSTER-ID eosdev
 6) COMMIT-INDEX 66
 7) LAST-APPLIED 66
 8) BLOCKED-WRITES 0
 9) LAST-STATE-CHANGE 324 (5 minutes, 24 seconds)
10) ----------
11) MYSELF eos1.math.tu-berlin.de:7777
12) VERSION 5.3.15.1
13) STATUS LEADER
14) NODE-HEALTH RED
15) JOURNAL-FSYNC-POLICY sync-important-updates
16) ----------
17) MEMBERSHIP-EPOCH 0
18) NODES eos1.math.tu-berlin.de:7777,eos2.math.tu-berlin.de:7777,eosfst3.math.tu-berlin.de:7777
19) OBSERVERS 
20) QUORUM-SIZE 2
21) ----------
22) REPLICA eos2.math.tu-berlin.de:7777 | ONLINE | UP-TO-DATE | LOG-SIZE 67 | VERSION 5.3.15.1
23) REPLICA eosfst3.math.tu-berlin.de:7777 | ONLINE | UP-TO-DATE | LOG-SIZE 67 | VERSION 5.3.15.1
info: run 'export REDISCLI_AUTH=`cat /etc/eos.keytab`; redis-cli -p `cat /var/run/eos/xrd.cf.qdb|grep xrd.port | cut -d ' ' -f 2` <<< raft-info' retc=0

The qdb log does not state any obvious problem and I’m not aware of any file permission problems. Can anyone tell me what to look for ?

Thank you,
Norbert

Ok, found it myself: Qdb needs at least 5GB space in /var/lib/qdb/ for a ‘green’ health status.
As mine was a small test install, I hadn’t enlarged it yet.

Norbert