I was migrating from 5.6.29 to 5.6.40. Initially, I attempted to do an in-place upgrade by running the "apt-get install --only-upgrade" command, but it failed with an error message about package dependency. So I went ahead to remove all the percona packages (server, client, etc...) by running "apt-get remove" and then reinstalled them with "apt-get install" command.

After installation, server is able to start but getting this error. 

root@healthdata-db-d01:~# apt-get install percona-server-server-5.6 Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be installed: libperconaserverclient18.1 percona-server-client-5.6 percona-server-common-5.6 Suggested packages: tinyca The following NEW packages will be installed: libperconaserverclient18.1 percona-server-client-5.6 percona-server-common-5.6 percona-server-server-5.6 0 upgraded, 4 newly installed, 0 to remove and 212 not upgraded. Need to get 13.5 MB of archives. After this operation, 138 MB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://repo.percona.com/apt/ trusty/main percona-server-common-5.6 amd64 5.6.40-84.0-1.trusty [12.0 kB] Get:2 http://repo.percona.com/apt/ trusty/main libperconaserverclient18.1 amd64 5.6.40-84.0-1.trusty [573 kB] Get:3 http://repo.percona.com/apt/ trusty/main percona-server-client-5.6 amd64 5.6.40-84.0-1.trusty [1,343 kB] Get:4 http://repo.percona.com/apt/ trusty/main percona-server-server-5.6 amd64 5.6.40-84.0-1.trusty [11.6 MB] Fetched 13.5 MB in 3s (3,668 kB/s) Preconfiguring packages ... Selecting previously unselected package percona-server-common-5.6. (Reading database ... 113185 files and directories currently installed.) Preparing to unpack .../percona-server-common-5.6_5.6.40-84.0-1.trusty_amd64.deb ... Unpacking percona-server-common-5.6 (5.6.40-84.0-1.trusty) ... Selecting previously unselected package libperconaserverclient18.1. Preparing to unpack .../libperconaserverclient18.1_5.6.40-84.0-1.trusty_amd64.deb ... Unpacking libperconaserverclient18.1 (5.6.40-84.0-1.trusty) ... Selecting previously unselected package percona-server-client-5.6. Preparing to unpack .../percona-server-client-5.6_5.6.40-84.0-1.trusty_amd64.deb ... Unpacking percona-server-client-5.6 (5.6.40-84.0-1.trusty) ... Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Setting up percona-server-common-5.6 (5.6.40-84.0-1.trusty) ... Selecting previously unselected package percona-server-server-5.6. (Reading database ... 113238 files and directories currently installed.) Preparing to unpack .../percona-server-server-5.6_5.6.40-84.0-1.trusty_amd64.deb ... Unpacking percona-server-server-5.6 (5.6.40-84.0-1.trusty) ... Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Processing triggers for ureadahead (0.100.0-16) ... ureadahead will be reprofiled on next reboot Setting up libperconaserverclient18.1 (5.6.40-84.0-1.trusty) ... Setting up percona-server-client-5.6 (5.6.40-84.0-1.trusty) ... Setting up percona-server-server-5.6 (5.6.40-84.0-1.trusty) ... * Stopping MySQL (Percona Server) mysqld [ OK ] * Percona Server is distributed with several useful UDF (User Defined Function) from Percona Toolkit. * Run the following commands to create these functions: mysql -e "CREATE FUNCTION fnv1a_64 RETURNS INTEGER SONAME 'libfnv1a_udf.so'" mysql -e "CREATE FUNCTION fnv_64 RETURNS INTEGER SONAME 'libfnv_udf.so'" mysql -e "CREATE FUNCTION murmur_hash RETURNS INTEGER SONAME 'libmurmur_udf.so'" * See http://www.percona.com/doc/percona-server/5.6/management/udf_percona_toolkit.html for more details * Starting MySQL (Percona Server) database server mysqld [ OK ] invoke-rc.d: initscript mysql, action "start" failed. dpkg: error processing package percona-server-server-5.6 (--configure): subprocess installed post-installation script returned error exit status 1 Processing triggers for libc-bin (2.19-0ubuntu6.9) ... Errors were encountered while processing: percona-server-server-5.6 E: Sub-process /usr/bin/dpkg returned an error code (1)