I have a perc5i (and perc5e) raid controller in my poweredge 2970 running centos 5.5. The RAID controller config is set for write-back policy, which I can confirm by checking in OpenManage. I also called Dell and ran their reporting application and had them double check to make sure everything looks OK hardware wise and they confirm that it does
Yet when CentOS boots is appears to use the write through policy as can be seen below from dmesg output. Am I wrong that CentOS should query the RAID controller and go into the correct write mode: write-back?
hub 1-5:1.0: 4 ports detected Vendor: DP Model: BACKPLANE Rev: 1.00 Type: Enclosure ANSI SCSI revision: 05 Vendor: DELL Model: PERC 5/i Rev: 1.03 Type: Direct-Access ANSI SCSI revision: 05 SCSI device sda: 2435317760 512-byte hdwr sectors (1246883 MB) sda: Write Protect is off sda: Mode Sense: 1f 00 00 08 SCSI device sda: drive cache: write through SCSI device sda: 2435317760 512-byte hdwr sectors (1246883 MB) sda: Write Protect is off sda: Mode Sense: 1f 00 00 08 SCSI device sda: drive cache: write through sda: sda1 sda2 sda3 sd 0:2:0:0: Attached scsi disk sda megasas: 0x1028:0x0015:0x1028:0x1f01: bus 16:slot 14:func 0 GSI 21 sharing vector 0x62 and IRQ 21 ACPI: PCI Interrupt 0000:10:0e.0[A] -> GSI 18 (level, low) -> IRQ 98 megasas: FW now in Ready state