Hotswap Disks

Regain Control infinite disk
1

Hotswap Disks are great, we can replace them seamlessly with no downtime to the host computer. Applications on the computer keep on running non-stop.

1. Hotswap SATA

Steps to perform BEFORE pulling hotswap SATA disks out:

  1. unmount
  2. sync (unmount takes care of this but it doesn’t hurt to run it)
  3. hdparm -Y /dev/sdX (put in sleep mode)
  4. echo offline > /sys/block/sdX/device/state (prevent any access)
  5. echo 1 > /sys/block/sdX/device/delete (delete associated driver)
  6. dmesg (to check that the drive is stopped)
  7. wait at least a minute for the disk to spin down
  8. pull the drive out slowly

Notes:

  1. SATA mode set to AHCI
  2. Enable any hot-swap support in the BIOS
  3. All steps above should be taken in sequence
  4. Waiting for spin down to finish before removing the disk is important, step 5 will also spin the disk down if step 3 does not perform the spin down.

2. Hotswap USB

  1. unmount
  2. sync
  3. echo 'offline' > /sys/block/sdX/device/state
  4. echo '1' > /sys/block/sdX/device/delete
  5. dmesg (to check that the drive is stopped)
  6. wait at least a minute for the disk to spin down
  7. unplug the drive slowly

Some other options:

  1. eject /dev/sdX
  2. udisksctl power-off -b /dev/sdX