Wednesday, October 07, 2009
A nice feature added to most Linux desktops in the last couple years, is the robust support of plugging almost any USB device into it and having it "just work". Printers, USB keys, Mp3 players, pretty much all "do the right thing" now. USB support in linux is comparable to Mac and Windows now...
... Including the flaws.
I don't understand all the magic that takes place behind the scenes to get a mp3 player to mount on /media. I understand it picks up the partition table name somehow, and gets an event...
But...
Why do we mount the devices read/write? And leave them mounted all the time? And require human
intervention to eject them? And have bad things happen if you don't do that? And (at least on the box I'm in front of) require you be logged in to the desktop to have it automount it in the first place?
Linux has had an automounter since the days of Apollo (Not the NASA version, the HP version), and for local devices it works pretty well. Automounters have never worked perfectly of course, particularly over failing networks...
It turned out pocobelle didn't do any of the magic that my desktop did, not mounting the drive at all, so I sat down and implemented automounts mostly the way I wanted them to work in the first place.
I added the following lines to /etc/auto.misc
sansa -fstype=vfat,rw,uid=1000,gid=1000,umask=022 :/dev/disk/by-id/usb-Rockbox_Internal_Storage_90000000000000000A4B4511712031AFD-0\:0-part1
sansa2 -fstype=vfat,rw,uid=1000,gid=1000,umask=022 :/dev/disk/by-id/usb-Rockbox_Internal_Storage_90000000000000000A4B4511712031AFD-0\:0-part2
(These are each one line. yes, my sansa runs Rockbox)
I created symlinks to the device in my public_html directory, so when it was plugged in I could stream media from it from any of the other devices in the house. When not plugged in, attempts to access it result in file not found, which is what I want. Also, when it is plugged in, I have a cron job setup to suck down some music at night from some internet radio stations I like (and not when it's not connected)
According to the setting in auto.master, it auto-dismounts 60 seconds after the last program using it stops, which makes it easy to just unplug it when I want to take it on the road... 99.99% of the time it will be dismounted - and I'd like it to mount read-only until something wants to write to it, which would take care of a few other nines... and implement a forced killall processes and umount triggered by a switch on one of the DIOs on the board to take care of the last .000001% of the problem.
... Including the flaws.
I don't understand all the magic that takes place behind the scenes to get a mp3 player to mount on /media. I understand it picks up the partition table name somehow, and gets an event...
But...
Why do we mount the devices read/write? And leave them mounted all the time? And require human
intervention to eject them? And have bad things happen if you don't do that? And (at least on the box I'm in front of) require you be logged in to the desktop to have it automount it in the first place?
Linux has had an automounter since the days of Apollo (Not the NASA version, the HP version), and for local devices it works pretty well. Automounters have never worked perfectly of course, particularly over failing networks...
It turned out pocobelle didn't do any of the magic that my desktop did, not mounting the drive at all, so I sat down and implemented automounts mostly the way I wanted them to work in the first place.
I added the following lines to /etc/auto.misc
sansa -fstype=vfat,rw,uid=1000,gid=1000,umask=022 :/dev/disk/by-id/usb-Rockbox_Internal_Storage_90000000000000000A4B4511712031AFD-0\:0-part1
sansa2 -fstype=vfat,rw,uid=1000,gid=1000,umask=022 :/dev/disk/by-id/usb-Rockbox_Internal_Storage_90000000000000000A4B4511712031AFD-0\:0-part2
(These are each one line. yes, my sansa runs Rockbox)
I created symlinks to the device in my public_html directory, so when it was plugged in I could stream media from it from any of the other devices in the house. When not plugged in, attempts to access it result in file not found, which is what I want. Also, when it is plugged in, I have a cron job setup to suck down some music at night from some internet radio stations I like (and not when it's not connected)
According to the setting in auto.master, it auto-dismounts 60 seconds after the last program using it stops, which makes it easy to just unplug it when I want to take it on the road... 99.99% of the time it will be dismounted - and I'd like it to mount read-only until something wants to write to it, which would take care of a few other nines... and implement a forced killall processes and umount triggered by a switch on one of the DIOs on the board to take care of the last .000001% of the problem.
Labels: automounts, pocobelle
¶ 8:54 AM
