Difference between revisions of "Hard drive dock notes"

Revision as of 03:40, 12 November 2013

LinuxMCE can almost support hard drive docking. But some pieces need to be engineered to facilitate the process. --Tschak909 02:40, 12 November 2013 (UTC)

UI Components

• Manage Hard Drive screen
• Attach Eject to hard drive button, make hidden if not removable disk.
• Disk is Ready for use, alert.
• Format Disk screen, with disk name, and "Windows or LinuxMCE" button.

Database Components

• Add Is Removable device data, so that we can do additional UI behavior

Script components

Eject_Removable_DIsk.sh

• Add Eject_Removable_Disk.sh which given a device #, and an Orbiter Device #, will do the following:
  • Stop UpdateMedia
  • Throw a lock "HardDriveEjected"
    • all StorageDevices_* scripts will WaitLock this, so that they are suspended while disk ejection happens.
  • exportfs -u the affected NFS share, on ALL media directors (TODO: Find out how best to do this, can StorageDevices_Setup.sh be used to this end?)
  • Unmount disk immediately.
  • Indicate that the Disk is safe to be removed by CMD_Display_Alert to orbiter PK_Device specified in second parameter.
  • Loop Wait for USB device to disappear from system, courtesy of UDEV (we keep the UUID, so we can track when this disk actually falls away. Loop.
  • When disk falls away, relinquish the lock.
  • Run StorageDevices_Setup.sh
  • Restart UpdateMedia

Format_Removable_Disk.sh

• Given a raw device path, and a filesystem name (ext3, ext4, xfs, jfs):
  • If disk is blank, Create a single partitionformat it with the given filesystem.
    • If the requested filesystem is NTFS, or FAT32, use the appropriate Microsoft compatible partition
    • Otherwise, use Linux partition.
  • If disk is not blank, politely exit with a non zero error code.

StorageDevices_Setup.sh

• While traversing disks to setup, find related interface parent given UUID.
  • If UUID belongs to a USB or eSATA channel, immediately assume that this disk is removable. Set Is Removable device data to true for this device.
    • If disk is indeed removable, and it now shows up, look at PK_Users device data, and run UpdateMedia for the affected paths immediately.

User Facing Behavior

This is preliminary, and subject to refinement, but I believe this will provide the following user facing behavior:

If this disk is Blank

• Show format screen.
• User formats disk
• User is then presented with the usual "Found a disk" screen.

If disk is already in device tree

• Simple notice will be shown top left, that disk is being added.
• Once UpdateMedia is done, then alert will be shown indicating to user that disk is ready to be used.

If Disk hasn't been placed in device tree

• Orbiter will ask whether user wants to use disk using usual methods.