UPDATED INSTRUCTIONS: for RTC on Raspberry pi for OMV are in a new thread. link below
Guide for installing a real time clock RTC in a raspberry pi on OMV 3 (jessie)
the remaining info below is out of date but the links are still helpful if you need further information and/or are installing on OMV 2!!!
I spent a couple of hours over the weekend doing new install of OMV 3 on a RPi v3 with a real time clock RTC module. Installation went well with steps below if anyone is interested:
1. download and install OMV 3.0.24 image to SD card.
2. install Raspi-config as this is not included in OMV image (apt-get update, apt-get install Raspi-config)
3. enable SPI and I2C through advance settings of raspi-config
Note that the following thread here at the OMV forum is very useful for RTC setup but relates to OMV 2.0 (wheezy) not OMV 3.0 (jessie)
RPi 2(RTC module): from unruly Stepchild to Wunderkind
4. setup/config RTC - as OMV 3.0 is built from Jessie much simpler RTC setup see page 2 of the following link
https://www.raspberrypi.org/forums/viewtopic.php?t=85683
5. Clear and reset folder2ram data - see page 2 of the following OMV forum / thread
Is it possible that system log entries and corrupt rrdcached data are included in the OMV boot image
6. delete/reset rrd data using following commands:
rm -r /var/lib/rrdcached/db/localhost
rm /var/lib/rrdcached/journal/*
7. clear syslog and reboot
