Upgrade FreeIPA cluster from v4.6 (el7) to v4.9 (el8)

[Mikhail Kiselev]

Hello, how can I update the cluster specified in the subject without data loss and service downtime?
I raised the host from EL8 and ran ipa-replica-install. Log output:
Configuring directory server (dirsrv). Estimated time: 30 seconds
  [1/38]: creating directory server instance
  [2/38]: tune ldbm plugin
  [3/38]: adding default schema
  [4/38]: enabling memberof plugin
  [5/38]: enabling winsync plugin
  [6/38]: configure password logging
  [7/38]: configuring replication version plugin
  [8/38]: enabling IPA enrollment plugin
  [9/38]: configuring uniqueness plugin
  [10/38]: configuring uuid plugin
  [11/38]: configuring modrdn plugin
  [12/38]: configuring DNS plugin
  [13/38]: enabling entryUSN plugin
  [14/38]: configuring lockout plugin
  [15/38]: configuring topology plugin
  [16/38]: creating indices
  [17/38]: enabling referential integrity plugin
  [18/38]: configuring certmap.conf
  [19/38]: configure new location for managed entries
  [20/38]: configure dirsrv ccache and keytab
  [21/38]: enabling SASL mapping fallback
  [22/38]: restarting directory server
  [23/38]: creating DS keytab
  [24/38]: ignore time skew for initial replication
  [25/38]: setting up initial replication
Starting replication, please wait until this has completed.
Update in progress, 11676 seconds elapsed

tail -f /var/log/dirsrv/slapd-OPENTECH-LOCAL/access
[02/Sep/2021:20:09:48.282984535 +0700] conn=84 op=6 SRCH base="cn=schema" scope=0 filter="(objectClass=*)" attrs="objectClasses"
[02/Sep/2021:20:09:48.366825074 +0700] conn=84 op=6 RESULT err=0 tag=101 nentries=1 wtime=0.000158968 optime=0.083844272 etime=0.083999242
[02/Sep/2021:20:09:48.368297195 +0700] conn=84 op=7 SRCH base="cn=schema" scope=0 filter="(objectClass=*)" attrs="attributeTypes"
[02/Sep/2021:20:09:48.455352207 +0700] conn=84 op=7 RESULT err=0 tag=101 nentries=1 wtime=0.000181242 optime=0.087049680 etime=0.087227596
[02/Sep/2021:20:09:48.598806315 +0700] conn=84 op=8 SRCH base="cn=schema" scope=0 filter="(objectClass=*)" attrs="objectClasses"
[02/Sep/2021:20:09:48.682435023 +0700] conn=84 op=8 RESULT err=0 tag=101 nentries=1 wtime=0.000253118 optime=0.083640981 etime=0.083890259
[02/Sep/2021:20:09:48.683959959 +0700] conn=84 op=9 SRCH base="cn=schema" scope=0 filter="(objectClass=*)" attrs="attributeTypes"
[02/Sep/2021:20:09:48.770110056 +0700] conn=84 op=9 RESULT err=0 tag=101 nentries=1 wtime=0.000208691 optime=0.086154930 etime=0.086360171
[02/Sep/2021:20:09:48.909866069 +0700] conn=84 op=10 EXT oid="2.16.840.1.113730.3.5.5" name="replication-multimaster-extop"
[02/Sep/2021:20:09:48.912490317 +0700] conn=84 op=10 RESULT err=0 tag=120 nentries=0 wtime=0.000289908 optime=0.002650238 etime=0.002936579

Am I doing the right thing and how long will the replica take to rise?