Load Peaks on Standby/Replication Server using Luks/dmcrypt

Hi,

we are using luks/dmycrypt to encrypt our pgdata volumes.
On some standby/replication machines we see load peaks up to 15x of the
primary server.
If we remove the dmcrypt/luks and run it on a non-encrypted device this
does not happen.

We have tried to analyze this but could not find where the load comes from.
Using atop, pg_top we do not see any waits, not on cpu and not on I/O,
just the higher load.

We see this on KVM hosts and also on Hardware (HDD, SSD, RAID/Non-RAID)
and also tried to set different powerprofiles in the BIOS.

Do you have any idea here? I am happy to get any information you need to
analyze this problem.

Thanks,
Dennis

--
Dennis Schwan

DBA
Database Services

1&1 De-Mail GmbH | Brauerstraße 50 | 76135 Karlsruhe | Germany
Phone: +49 721 91374-8738
E-Mail: dennis(dot)schwan(at)1und1(dot)de | Web: www.1und1.de

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