After a hot/warm boot (pressing Ctrl + Alt + Del) or reboot all five drives are detected: $ lsscsi [4:0:0:0] disk ATA OCZ-VERTEX 1.3 /dev/sda [5:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdb [7:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdc [8:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdd [9:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sde [10:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdf [12:0:0:0] process Marvell 91xx Config 1.01 - But after a cold boot (power cycling) still only 3 of 5 PUIS drives are detected: $ lsscsi [4:0:0:0] disk ATA OCZ-VERTEX 1.3 /dev/sda [5:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdb [7:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdc [9:0:0:0] disk ATA Hitachi HDS5C302 MZ4O /dev/sdd [12:0:0:0] process Marvell 91xx Config 1.01 - The relevant dmesg part for a warm boot: ====== ... [ 3.178775] ahci 0000:03:00.0: irq 44 for MSI/MSI-X [ 3.211923] ahci 0000:03:00.0: AHCI 0001.0200 32 slots 8 ports 6 Gbps 0xff impl SATA mode [ 3.211924] ahci 0000:03:00.0: flags: 64bit ncq pio [ 3.212601] scsi5 : ahci [ 3.212662] scsi6 : ahci [ 3.212710] scsi7 : ahci [ 3.212757] scsi8 : ahci [ 3.212802] scsi9 : ahci [ 3.212849] scsi10 : ahci [ 3.212896] scsi11 : ahci [ 3.212941] scsi12 : ahci [ 3.212964] ata6: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510100 irq 44 [ 3.212966] ata7: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510180 irq 44 [ 3.212967] ata8: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510200 irq 44 [ 3.212969] ata9: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510280 irq 44 [ 3.212970] ata10: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510300 irq 44 [ 3.212972] ata11: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510380 irq 44 [ 3.212973] ata12: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510400 irq 44 [ 3.212975] ata13: SATA max UDMA/133 abar m2048@0xf0510000 port 0xf0510480 irq 44 [ 3.343965] usb 3-10.1: new full-speed USB device number 3 using xhci_hcd [ 3.563530] ata13: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 3.563551] ata12: SATA link down (SStatus 0 SControl 300) [ 3.563573] ata9: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.563591] ata6: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.563612] ata10: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.563631] ata7: SATA link down (SStatus 0 SControl 300) [ 3.563652] ata8: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.563669] ata11: SATA link down (SStatus 0 SControl 300) [ 3.563684] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 3.595296] ata13.00: ATAPI: MARVELL VIRTUALL, 1.09, max UDMA/66 [ 3.626338] usb 3-10.1: New USB device found, idVendor=05ac, idProduct=0205 [ 3.626339] usb 3-10.1: New USB device strings: Mfr=1, Product=3, SerialNumber=0 [ 3.626340] usb 3-10.1: Product: Apple Extended USB Keyboard [ 3.626341] usb 3-10.1: Manufacturer: Mitsumi Electric [ 3.626364] ata5.00: ACPI cmd ef/10:06:00:00:00:00 (SET FEATURES) succeeded [ 3.626366] ata5.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out [ 3.626367] ata5.00: ACPI cmd b1/c1:00:00:00:00:00 (DEVICE CONFIGURATION OVERLAY) filtered out [ 3.626404] usb 3-10.1: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes [ 3.626405] usb 3-10.1: ep 0x82 - rounding interval to 1024 microframes, ep desc says 2040 microframes [ 3.657552] ata13.00: configured for UDMA/66 [ 3.688238] ata10.00: ATA-8: Hitachi HDS5C3020BLE630, MZ4OAAB0, max UDMA/133 [ 3.688239] ata10.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.688245] ata8.00: ATA-8: Hitachi HDS5C3020BLE630, MZ4OAAB0, max UDMA/133 [ 3.688246] ata8.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.688249] ata6.00: ATA-8: Hitachi HDS5C3020BLE630, MZ4OAAB0, max UDMA/133 [ 3.688249] ata6.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.688253] ata9.00: ATA-8: Hitachi HDS5C3020BLE630, MZ4OAAB0, max UDMA/133 [ 3.688253] ata9.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.718452] ata5.00: ATA-7: OCZ-VERTEX, 1.3, max UDMA/133 [ 3.718453] ata5.00: 125045424 sectors, multi 1: LBA48 NCQ (depth 31/32), AA [ 3.777817] hidraw: raw HID events driver (C) Jiri Kosina [ 3.835198] ata5.00: ACPI cmd ef/10:06:00:00:00:00 (SET FEATURES) succeeded [ 3.835199] ata5.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out [ 3.835201] ata5.00: ACPI cmd b1/c1:00:00:00:00:00 (DEVICE CONFIGURATION OVERLAY) filtered out [ 3.863060] ata6.00: configured for UDMA/133 [ 3.863067] ata8.00: configured for UDMA/133 [ 3.863072] ata9.00: configured for UDMA/133 [ 3.919092] ata5.00: configured for UDMA/133 [ 3.919158] scsi 4:0:0:0: Direct-Access ATA OCZ-VERTEX 1.3 PQ: 0 ANSI: 5 [ 3.919287] sd 4:0:0:0: [sda] 125045424 512-byte logical blocks: (64.0 GB/59.6 GiB) [ 3.919317] sd 4:0:0:0: [sda] Write Protect is off [ 3.919318] sd 4:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 3.919328] sd 4:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 3.919443] sd 4:0:0:0: Attached scsi generic sg0 type 0 [ 3.919518] scsi 5:0:0:0: Direct-Access ATA Hitachi HDS5C302 MZ4O PQ: 0 ANSI: 5 [ 3.919584] sd 5:0:0:0: Attached scsi generic sg1 type 0 [ 3.919644] scsi 7:0:0:0: Direct-Access ATA Hitachi HDS5C302 MZ4O PQ: 0 ANSI: 5 [ 3.919712] sd 7:0:0:0: [sdc] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 3.919713] sd 7:0:0:0: [sdc] 4096-byte physical blocks [ 3.919734] sd 7:0:0:0: [sdc] Write Protect is off [ 3.919735] sd 7:0:0:0: [sdc] Mode Sense: 00 3a 00 00 [ 3.919744] sd 7:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 3.919805] sd 7:0:0:0: Attached scsi generic sg2 type 0 [ 3.919887] scsi 8:0:0:0: Direct-Access ATA Hitachi HDS5C302 MZ4O PQ: 0 ANSI: 5 [ 3.919948] sd 8:0:0:0: Attached scsi generic sg3 type 0 [ 3.919978] sd 8:0:0:0: [sdd] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 3.919979] sd 8:0:0:0: [sdd] 4096-byte physical blocks [ 3.919997] sd 5:0:0:0: [sdb] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 3.919997] sd 5:0:0:0: [sdb] 4096-byte physical blocks [ 3.920018] sd 8:0:0:0: [sdd] Write Protect is off [ 3.920019] sd 8:0:0:0: [sdd] Mode Sense: 00 3a 00 00 [ 3.920036] sd 8:0:0:0: [sdd] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 3.920056] sd 5:0:0:0: [sdb] Write Protect is off [ 3.920057] sd 5:0:0:0: [sdb] Mode Sense: 00 3a 00 00 [ 3.920067] sd 5:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 4.027413] sda: sda1 sda2 < sda5 > [ 4.027577] sd 4:0:0:0: [sda] Attached SCSI disk [ 4.079988] sdc: unknown partition table [ 4.080027] sdd: unknown partition table [ 4.080114] sd 8:0:0:0: [sdd] Attached SCSI disk [ 4.080140] sd 7:0:0:0: [sdc] Attached SCSI disk [ 4.131390] sdb: unknown partition table [ 4.131487] sd 5:0:0:0: [sdb] Attached SCSI disk [ 4.183479] usbcore: registered new interface driver usbhid [ 4.183480] usbhid: USB HID core driver [ 4.287133] input: Mitsumi Electric Apple Extended USB Keyboard as /devices/pci0000:00/0000:00:14.0/usb3/3-10/3-10.1/3-10.1:1.0/input/input5 [ 4.287426] hid-generic 0003:05AC:0205.0001: input,hidraw0: USB HID v1.10 Keyboard [Mitsumi Electric Apple Extended USB Keyboard] on usb-0000:00:14.0-10.1/input0 [ 4.336770] input: Mitsumi Electric Apple Extended USB Keyboard as /devices/pci0000:00/0000:00:14.0/usb3/3-10/3-10.1/3-10.1:1.1/input/input6 [ 4.336792] ata10.00: configured for UDMA/133 [ 4.336855] scsi 9:0:0:0: Direct-Access ATA Hitachi HDS5C302 MZ4O PQ: 0 ANSI: 5 [ 4.336937] sd 9:0:0:0: Attached scsi generic sg4 type 0 [ 4.337009] sd 9:0:0:0: [sde] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 4.337010] sd 9:0:0:0: [sde] 4096-byte physical blocks [ 4.337032] sd 9:0:0:0: [sde] Write Protect is off [ 4.337033] sd 9:0:0:0: [sde] Mode Sense: 00 3a 00 00 [ 4.337043] sd 9:0:0:0: [sde] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 4.337561] hid-generic 0003:05AC:0205.0002: input,hidraw1: USB HID v1.10 Device [Mitsumi Electric Apple Extended USB Keyboard] on usb-0000:00:14.0-10.1/input1 [ 4.387883] scsi 12:0:0:0: Processor Marvell 91xx Config 1.01 PQ: 0 ANSI: 5 [ 4.387958] scsi 12:0:0:0: Attached scsi generic sg5 type 3 [ 4.490779] sde: unknown partition table [ 4.490872] sd 9:0:0:0: [sde] Attached SCSI disk [ 4.845049] random: nonblocking pool is initialized [ 5.063803] ata11: exception Emask 0x10 SAct 0x0 SErr 0x4000000 action 0xe frozen [ 5.063804] ata11: irq_stat 0x80000040, connection status changed [ 5.063804] ata11: SError: { DevExch } [ 5.063808] ata11: hard resetting link [ 6.113055] ata11: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 6.244474] ata11.00: ATA-8: Hitachi HDS5C3020BLE630, MZ4OAAB0, max UDMA/133 [ 6.244475] ata11.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 6.459574] ata11.00: configured for UDMA/133 [ 6.459577] ata11: EH complete [ 6.459635] scsi 10:0:0:0: Direct-Access ATA Hitachi HDS5C302 MZ4O PQ: 0 ANSI: 5 [ 6.459747] sd 10:0:0:0: [sdf] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 6.459748] sd 10:0:0:0: [sdf] 4096-byte physical blocks [ 6.459771] sd 10:0:0:0: [sdf] Write Protect is off [ 6.459772] sd 10:0:0:0: [sdf] Mode Sense: 00 3a 00 00 [ 6.459782] sd 10:0:0:0: [sdf] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 6.459883] sd 10:0:0:0: Attached scsi generic sg6 type 0 [ 6.676198] sdf: unknown partition table [ 6.676292] sd 10:0:0:0: [sdf] Attached SCSI disk ... ====== ======