This last weekend at sf-lug meeting Rick Moen mentioned a Pi-like
board with an actual pci-express port (!)
You could place a SATA controller in that slot and make yourself
a small file server.
So people have been hanging USB 3 drives off the Pi 4 and making
file servers that way.
I just discovered that USB 3 drives are accessed in Linux via two
different drivers "uas" (USB Attached Scsi) and "usb-storage"
And there is quite a difference between the two:
So looking at the drives I have:
tom@tom-desktop:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 3.7T 0 disk
├─sda1 8:1 0 1T 0 part /mnt/steam
└─sda2 8:2 0 1T 0 part
sdb 8:16 0 931.5G 0 disk
└─sdb1 8:17 0 931.5G 0 part
sdc 8:32 0 238.5G 0 disk
├─sdc1 8:33 0 190M 0 part /boot/efi
├─sdc2 8:34 0 111.8G 0 part /
├─sdc3 8:35 0 7.5G 0 part [SWAP]
└─sdc4 8:36 0 119.1G 0 part
sdd 8:48 0 931.5G 0 disk
└─sdd1 8:49 0 931.5G 0 part /media/tom/Toms 1TB
sde 8:64 0 4.6T 0 disk
└─sde1 8:65 0 4.6T 0 part /media/tom/Tom's Passport
tom@tom-desktop:~$ lsusb -t
/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
|__ Port 3: Dev 9, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
|__ Port 4: Dev 8, If 0, Class=Mass Storage, Driver=uas, 5000M
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 480M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M
|__ Port 5: Dev 3, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 5: Dev 3, If 1, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 5: Dev 3, If 2, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 6: Dev 4, If 2, Class=Audio, Driver=snd-usb-audio, 12M
|__ Port 6: Dev 4, If 0, Class=Audio, Driver=snd-usb-audio, 12M
|__ Port 6: Dev 4, If 3, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 6: Dev 4, If 1, Class=Audio, Driver=snd-usb-audio, 12M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M
|__ Port 6: Dev 3, If 0, Class=Video, Driver=uvcvideo, 480M
|__ Port 6: Dev 3, If 1, Class=Video, Driver=uvcvideo, 480M
sdd is a 1TB 2.5in SATA drive connected through an Anker SATA to USB 3 adapter
and it uses "uas" : |__ Port 4: Dev 8, If 0, Class=Mass Storage, Driver=uas, 5000M
sde is a 5TB WD Passport 2.5in external USB and it uses "usb-storage"
|__ Port 3: Dev 9, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
I was thinking of using the 5TB with the PI but now I think it may not be the
best. Not too many options there. The USB interface on the Passport drives
is built in -- there is no SATA inside.
Also I come to find out the Passport is one of the dreaded SMR drives:
Though I am not really expecting to do a zfs raid on a Pi4
uas vs usb-storage is also a factor in the new USB boot firmware (well I think it is
still in beta) Some are finding the PI won't boot from a drive detected as uas.
Thomas