Hey folks, I have my system (Gigabyte P55A-UD4 r1 F15 firmware) configured in AHCI mode with a 1+3 TB HDDs, and a DVD drive. ata5 = 1TB SATA (msdos partition scheme) ata9 = DVD SATA ata10 = 3TB SATA (GPT scheme to use 3TB as one, but not a boot drive) ata16 = Appears to be virtual "Marvell" device (I am not using hardware or fake RAID, and have disabled eSATA port) I have two 6Gbps SATA ports, and the rest are 3 I think. One of the 6GB ports goes to the 3TB drive, the other goes to a docking bay in the case that I use to do occasional offline backups. The kernel seems to be bitching about the DVD drive all the time (and sometimes my 1TB drive), and I'm not quite sure why. Buggy AHCI? Crappy SATA cables? Something else? Used AHCI mode for ages, but only with upgrade to Ubuntu version that I've noticed more bitching. The other day, my 1TB drive got pushed into read only mode on boot - I did several SMART tests and an fsck from a live environment and nothing out of the ordinary came up (I have recently installed Windows 10 in dual boot, but prior to that had Windows 7 - Windows didn't touch grub at all). Using search: zegrep 'ata([59]|10|16)|status: \{' /var/log/syslog.3.gz I've pulled out two examples of boot time fun: [ 1.062473] ata5: SATA max UDMA/133 abar m2048@0xfbffd000 port 0xfbffd200 irq 37 [ 1.078468] ata9: SATA max UDMA/133 abar m2048@0xfbdff000 port 0xfbdff100 irq 39 [ 1.078470] ata10: SATA max UDMA/133 abar m2048@0xfbdff000 port 0xfbdff180 irq 39 [ 1.078480] ata16: SATA max UDMA/133 abar m2048@0xfbdff000 port 0xfbdff480 irq 39 [ 1.400286] ata16: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 1.400383] ata10: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 1.400411] ata16.00: ATAPI: MARVELL VIRTUALL, 1.09, max UDMA/66 [ 1.400689] ata16.00: configured for UDMA/66 [ 1.401396] ata10.00: ATA-8: WDC WD3000FYYZ-01UL1B0, 01.01K01, max UDMA/133 [ 1.401401] ata10.00: 5860533168 sectors, multi 8: LBA48 NCQ (depth 31/32), AA [ 1.403407] ata10.00: configured for UDMA/133 [ 1.404179] ata9: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 1.405880] ata9.00: ATAPI: ATAPI iHAS124 Y, BL0V, max UDMA/100 [ 1.408124] ata9.00: configured for UDMA/100 [ 2.192223] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 2.207881] ata5.00: ATA-8: WDC WD1002FAEX-00Z3A0, 05.01D05, max UDMA/133 [ 2.207887] ata5.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 2.209995] ata5.00: configured for UDMA/133 [ 3.184967] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.185027] ata9.00: irq_stat 0x40000001 [ 3.200944] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.201002] ata9.00: irq_stat 0x40000001 [ 3.216173] ata16.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.216223] ata16.00: irq_stat 0x40000001 [ 3.216271] ata16.00: cmd a0/01:00:00:00:01/00:00:00:00:00/a0 tag 1 dma 16640 in [ 3.216336] ata16.00: status: { DRDY } [ 3.268939] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.268988] ata9.00: irq_stat 0x40000001 [ 3.284496] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.284545] ata9.00: irq_stat 0x40000001 [ 3.300450] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.300499] ata9.00: irq_stat 0x40000001 [ 3.324919] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.324967] ata9.00: irq_stat 0x40000001 [ 3.340548] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.340596] ata9.00: irq_stat 0x40000001 [ 3.356589] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.356636] ata9.00: irq_stat 0x40000001 [ 3.380945] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.380993] ata9.00: irq_stat 0x40000001 [ 10.885181] ata5.00: exception Emask 0x0 SAct 0x40000007 SErr 0x0 action 0x0 [ 10.885257] ata5.00: irq_stat 0x40000008 [ 10.885322] ata5.00: failed command: READ FPDMA QUEUED [ 10.885382] ata5.00: cmd 60/00:f0:c0:3d:83/01:00:1d:00:00/40 tag 30 ncq 131072 in [ 10.885490] ata5.00: status: { DRDY ERR } [ 10.885545] ata5.00: error: { UNC } [ 10.889441] ata5.00: configured for UDMA/133 [ 10.889571] ata5: EH complete [ 13.185375] ata5.00: exception Emask 0x0 SAct 0x3000000 SErr 0x0 action 0x0 [ 13.185463] ata5.00: irq_stat 0x40000008 [ 13.185526] ata5.00: failed command: READ FPDMA QUEUED [ 13.185585] ata5.00: cmd 60/08:c0:e0:3d:83/00:00:1d:00:00/40 tag 24 ncq 4096 in [ 13.185693] ata5.00: status: { DRDY ERR } [ 13.185749] ata5.00: error: { UNC } [ 13.189954] ata5.00: configured for UDMA/133 [ 13.190146] ata5: EH complete [ 15.037279] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 15.037342] ata9.00: irq_stat 0x40000001 [ 15.053304] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 15.053368] ata9.00: irq_stat 0x40000001 [ 15.073351] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 15.073423] ata9.00: irq_stat 0x40000001 [ 15.097661] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 15.097734] ata9.00: irq_stat 0x40000001 [ 15.117315] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 15.117378] ata9.00: irq_stat 0x40000001 [ 15.137616] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 15.137689] ata9.00: irq_stat 0x40000001 [ 139.870144] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 139.870148] ata9.00: irq_stat 0x40000001 [ 139.890320] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 139.890324] ata9.00: irq_stat 0x40000001 [ 139.897804] ata9: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 t4 [ 139.897807] ata9: irq_stat 0x40000001 [ 1.063019] ata5: SATA max UDMA/133 abar m2048@0xfbffd000 port 0xfbffd200 irq 37 [ 1.078151] ata9: SATA max UDMA/133 abar m2048@0xfbdff000 port 0xfbdff100 irq 39 [ 1.078153] ata10: SATA max UDMA/133 abar m2048@0xfbdff000 port 0xfbdff180 irq 39 [ 1.078163] ata16: SATA max UDMA/133 abar m2048@0xfbdff000 port 0xfbdff480 irq 39 [ 1.396028] ata16: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 1.396046] ata10: SATA link up 6.0 Gbps (SStatus 133 SControl 300) [ 1.396200] ata16.00: ATAPI: MARVELL VIRTUALL, 1.09, max UDMA/66 [ 1.396470] ata16.00: configured for UDMA/66 [ 1.397147] ata10.00: ATA-8: WDC WD3000FYYZ-01UL1B0, 01.01K01, max UDMA/133 [ 1.397153] ata10.00: 5860533168 sectors, multi 8: LBA48 NCQ (depth 31/32), AA [ 1.399072] ata10.00: configured for UDMA/133 [ 1.403953] ata9: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [ 1.405630] ata9.00: ATAPI: ATAPI iHAS124 Y, BL0V, max UDMA/100 [ 1.407746] ata9.00: configured for UDMA/100 [ 2.191935] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 2.204992] ata5.00: ATA-8: WDC WD1002FAEX-00Z3A0, 05.01D05, max UDMA/133 [ 2.204998] ata5.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 2.207106] ata5.00: configured for UDMA/133 [ 3.184727] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.184787] ata9.00: irq_stat 0x40000001 [ 3.200768] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.200826] ata9.00: irq_stat 0x40000001 [ 3.215932] ata16.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.215991] ata16.00: irq_stat 0x40000001 [ 3.216044] ata16.00: cmd a0/01:00:00:00:01/00:00:00:00:00/a0 tag 1 dma 16640 in [ 3.216111] ata16.00: status: { DRDY } [ 3.276729] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.276788] ata9.00: irq_stat 0x40000001 [ 3.292414] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.292472] ata9.00: irq_stat 0x40000001 [ 3.308295] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.308343] ata9.00: irq_stat 0x40000001 [ 3.332740] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.332799] ata9.00: irq_stat 0x40000001 [ 3.352472] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.352530] ata9.00: irq_stat 0x40000001 [ 3.372280] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.372328] ata9.00: irq_stat 0x40000001 [ 3.396795] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 3.396854] ata9.00: irq_stat 0x40000001 [ 7.936707] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 7.936770] ata9.00: irq_stat 0x40000001 [ 7.984588] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 7.984652] ata9.00: irq_stat 0x40000001 [ 8.000647] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 8.000714] ata9.00: irq_stat 0x40000001 [ 8.024891] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 8.024958] ata9.00: irq_stat 0x40000001 [ 8.040638] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 8.040700] ata9.00: irq_stat 0x40000001 [ 8.060998] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 8.061060] ata9.00: irq_stat 0x40000001 [ 649.042550] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 649.042557] ata9.00: irq_stat 0x40000001 [ 649.062840] ata9.00: exception Emask 0x1 SAct 0x0 SErr 0x0 action 0x0 [ 649.062846] ata9.00: irq_stat 0x40000001