Failed to Start After Moving /var to Another Drive

I am running CentOS 7. I have /var on a separate hard drive, and smartctl shows that it has some read error. Hence, I would like to move /var to another hard drive. For the new hard drive, I used gparted to create two partitions (1MB alignment). Then, I mounted one partition to /mnt/var_new and then rsync -avHPSAX --filter='-x security.selinux' /var/ /mnt/var_new/. And as expected, one file was failed to sync (that just confirmed why smartctl got read errors): WARNING: cache/yum/x86_64/7/centos-sclo-sclo/gen/primary_db.sqlite failed verification -- update discarded (will try again). cache/yum/x86_64/7/centos-sclo-sclo/gen/primary_db.sqlite 1,607,680 100% 2.81MB/s 0:00:00 (xfr#3, ir-chk=1309/1607) rsync: read errors mapping "/var/cache/yum/x86_64/7/centos-sclo-sclo/gen/primary_db.sqlite": Input/output error (5) ERROR: cache/yum/x86_64/7/centos-sclo-sclo/gen/primary_db.sqlite failed verification -- update discarded. And no other file was failed to sync (I re-ran rsync again to confirm). Then, I correctly removed the entry that mounted the old /var and added a new entry to mount the new /var. Then, I rebooted and then it failed to start with tons of failures (just plain black screen). Then, I booted into emergency mode, and the new /var did mount correctly that I could see the related files there. I did read some articles that /var needed to be in 755 mode and /var/tmp needed to have the sticky bit set. I had both. What did I do wrong? Thanks!