Found out something about megacli and checked settings for cache and stuff following
http://highperfpostgres.com/guides/lsi-megaraid-setup-for-postgresql/ Did I set a wrong Strip Size for the third array? good night, late here ... Stefan # megacli -LDInfo -Lall -aALL Adapter 0 -- Virtual Drive Information: Virtual Drive: 0 (Target Id: 0) Name :root RAID Level : Primary-6, Secondary-3, RAID Level Qualifier-3 Size : 500.0 GB Sector Size : 512 Is VD emulated : No Parity Size : 250.0 GB State : Optimal Strip Size : 256 KB Number Of Drives : 6 Span Depth : 1 Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Default Access Policy: Read/Write Current Access Policy: Read/Write Disk Cache Policy : Disabled Encryption Type : None Bad Blocks Exist: No Is VD Cached: No Virtual Drive: 1 (Target Id: 1) Name :swap RAID Level : Primary-6, Secondary-3, RAID Level Qualifier-3 Size : 8.0 GB Sector Size : 512 Is VD emulated : No Parity Size : 4.0 GB State : Optimal Strip Size : 64 KB Number Of Drives : 6 Span Depth : 1 Default Cache Policy: WriteBack, ReadAheadNone, Cached, No Write Cache if Bad BBU Current Cache Policy: WriteBack, ReadAheadNone, Cached, No Write Cache if Bad BBU Default Access Policy: Read/Write Current Access Policy: Read/Write Disk Cache Policy : Disabled Encryption Type : None Bad Blocks Exist: No Is VD Cached: No Virtual Drive: 2 (Target Id: 2) Name :lvm RAID Level : Primary-6, Secondary-3, RAID Level Qualifier-3 Size : 1.321 TB Sector Size : 512 Is VD emulated : No Parity Size : 676.5 GB State : Optimal Strip Size : 64 KB Number Of Drives : 6 Span Depth : 1 Default Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteBack, ReadAdaptive, Direct, No Write Cache if Bad BBU Default Access Policy: Read/Write Current Access Policy: Read/Write Disk Cache Policy : Disabled Encryption Type : None Bad Blocks Exist: No Is VD Cached: No