I recently set up OMV 5 on an AMD system (A75m-itx motherboard). it has 4x SATA ports. OMV 5.x is installed on USB connected SSD. After playing a bit with this system, I am now ready to add HDDs to it.
I have 3x HGST 2TB (HDS5C3020ALA632) hard drives. I believe these are 5940 RPM.
I also have 1x 2TB HGST drive (HDS722020ALA330). This is a 7200 RPM drive.
My intention is to create a RAID5. So 4x TB drives resulting in a 6TB data volume. All my data will be backed up to a 6 TB USB connected external hard drive.
Question: Is it OK to create a RAID with drives that have different RPM speeds?