I have been trying to upgrade postgres 9.5 to 9.6 with pg_upgrade
Everything seems to start fine but when pg_upgrade gets to "Copying
user relation files"
It takes ages to complete copying.
ie
Each file like
/var/lib/pgsql/9.5/data/base/24602/25140
is 1G and taking ~5-10 minutes to copyand that directory is 223G of
about 990 files
After a couple of hours running pg_upgrade I had to give up.
looking a iotop I was seeing
99% IO load caused by [md0_raid1]
and only seeing pg_upgrade go to 99% every 3-4 seconds
I had no other processes using io or high cpu.
Has anyone got any pointers of what could be the issue ?
Ps running cp on /var/lib/pgsql/9.5/data/base/24602/25140 to my home
directory is instantaneous
System is Centos 7
Thanks