I am currently developing an embedded product using Linux that must have a USB based multi port flash reader. It must support the most common flash card form factors and USB flash drives. It should also be internal (for example fit into a 3.5 inch internal drive bay). Can anyone recommend a flash reader that they have tested with Linux that meets these requirements?

If so what flavor of Linux and what version(s) have you tried it on? Did you have to do anything special to get the flash drives recognized and mounted (in addition to adding an entry to fstab, creating a mount directory and mounting the device)? Which flash cards/drives did you try? Any other useful tidbits of info?

I am partial to Redhat if you have info on that (9 or FC 3) but only because I haven't used the Debian, Suse and Slackware distributions in about 3 years.

Hi,

My father's machine has got an el-cheapo 'In-win Developments' 6 in 1 card reader fitted (goes in a 3.5" bay) which works well with SuSE 9.2, Mandrake 10...

The latest distros (SuSE 9.2 included here), such as Fedora Core 3, Ubuntu, use dbus/HAL/udev - so you plug a card into the reader and up pops a dialog box on-screen - neat. Earlier distros (such as the Mandrake 10 above) still offer support, but the card has to be manually mounted - no big deal, just an extra step.

Thanks for the info. I put in my PO for that In-Win device. I hope it doesn't go obsolete soon. I also ordered a couple of others for testing and will post the results of those tests when I finish.

Results:

I was not able to order that In-Win device because it was obsolete. Instead I tested a Sabrent 15 in 1 (now obsolete), an Apacer 15 in 1 and an Addonics Digidrive. Each of these usb flash card readers has 4 slots for reading the different types of flash drives and all 3 worked the same way. I did like that the Addonics came with a cable to go from the internal usb header that the device uses, to an external one (useful for my testing), even though the cable was incorrectly wired (easily fixed). But I liked that the Sabrent and the Apacer had an additional USB connector on the front.

In order to mount the devices, I found the best way (on Redhat 9 at least) was to edit /etc/modules.conf and add the line:
options scsi_mod max_scsi_luns=8
Then create 4 different mount directories in /mnt, one for each drive.
(For example /mnt/flash1, /mnt/flash2, /mnt/flash3, /mnt/flash4)
After installing the USB reader and rebooting, I could then mount each of the drives:
mount -t vfat /dev/sda1 /mnt/flash1
mount -t vfat /dev/sdb1 /mnt/flash2
mount -t vfat /dev/sdc1 /mnt/flash3
mount -t vfat /dev/sdd1 /mnt/flash4
assuming flash media was installed in each of the card reader slots.

One problem that I had was that on a non-updated Redhat 9 install, secure digital and sony memory stick media with the write protect tab on were not detected as read only using the mount function called in a C program. This is fixed in the updates for Redhat 9. I used yum to get these updates and then read only detection worked properly.