I probably am doing something strange that is a (minor?) problem and I wonder if there is a fix (maybe adding a script to the init scripts).
I have created a RAID1 (mirror) set with the uSD card and a partition of a USB attached SATA SSD drive. The M64 boots off the uSD card (that is where uBoot is installed). The boot process starts the RAID array in degraded mode, because the USB attached SATA SSD drive is not seen until a little later in the boot process. Is there a way to get the USB Disk settled earlier in the boot process?
Here is the relevant parts of dmesg:
[ 34.412844] usb 3-1.4: new full-speed USB device number 13 using ehci-platform [ 34.642763] usb 3-1.4: New USB device found, idVendor=0a05, idProduct=7211, bcdDevice= 1.00 [ 34.642772] usb 3-1.4: New USB device strings: Mfr=0, Product=1, SerialNumber=0 [ 34.642778] usb 3-1.4: Product: USB2.0 HUB [ 34.643534] hub 3-1.4:1.0: USB hub found [ 34.643762] hub 3-1.4:1.0: 4 ports detected [ 34.985541] usb 3-1.4: USB disconnect, device number 13 [ 35.004949] usb 3-1.4-port2: attempt power cycle [ 35.442593] md/raid1:md0: active with 1 out of 2 mirrors [ 35.442692] md0: detected capacity change from 0 to 31591563264 [ 35.504867] usb 3-1.4: new full-speed USB device number 18 using ehci-platform [ 35.722922] usb 3-1.4: New USB device found, idVendor=0a05, idProduct=7211, bcdDevice= 1.00 [ 35.722936] usb 3-1.4: New USB device strings: Mfr=0, Product=1, SerialNumber=0 [ 35.722943] usb 3-1.4: Product: USB2.0 HUB [ 35.723753] hub 3-1.4:1.0: USB hub found [ 35.723974] hub 3-1.4:1.0: 4 ports detected [ 42.609213] usb 3-1.4.2: new full-speed USB device number 44 using ehci-platform [ 42.816624] usb 3-1.4.2: not running at top speed; connect to a high speed hub [ 42.818032] usb 3-1.4.2: New USB device found, idVendor=152d, idProduct=2329, bcdDevice= 1.00 [ 42.818038] usb 3-1.4.2: New USB device strings: Mfr=1, Product=2, SerialNumber=5 [ 42.818043] usb 3-1.4.2: Product: USB to ATA/ATAPI bridge [ 42.818047] usb 3-1.4.2: Manufacturer: JMicron [ 42.818051] usb 3-1.4.2: SerialNumber: 153510A117BB [ 42.819280] usb-storage 3-1.4.2:1.0: USB Mass Storage device detected [ 42.819559] usb-storage 3-1.4.2:1.0: Quirks match for vid 152d pid 2329: 8020 [ 42.819639] scsi host0: usb-storage 3-1.4.2:1.0 [ 43.887741] scsi 0:0:0:0: Direct-Access Micron_M 500DC_MTFDDAK480 0144 PQ: 0 ANSI: 2 CCS [ 43.888506] sd 0:0:0:0: Attached scsi generic sg0 type 0 [ 43.889590] sd 0:0:0:0: [sda] 937703088 512-byte logical blocks: (480 GB/447 GiB) [ 43.890820] sd 0:0:0:0: [sda] Write Protect is off [ 43.890831] sd 0:0:0:0: [sda] Mode Sense: 28 00 00 00 [ 43.892124] sd 0:0:0:0: [sda] No Caching mode page found [ 43.902077] sd 0:0:0:0: [sda] Assuming drive cache: write through [ 43.954505] sda: sda1 sda2 [ 44.071996] sd 0:0:0:0: [sda] Attached SCSI disk
It is clear that the USB hub is itself seen early in the boot process, but it appears that detecting the attached devices is defered for some reason. Is there some trick to fix that? I am able to hot add the partition later (ala mdadm /dev/md0 --add /dev/sda1), but I would rather not have to do that.