HOWTO: work around SATA HDD hotplug problem (in Linux)

Sometimes some SATA controllers do not recognize an attached HDD if it was hot-plugged after the Linux system has been booted. Fortunately, there're some simple workarounds (note: it should work for some PATA controllers too).

1. A standard "soft" solution (should work by default):
   0. Connect the HDD to the SATA controller (and make sure it doesn't get auto-recognized by the system).
   1. Force a rescan of SCSI buses:

      # for h in /sys/class/scsi_host/host*/scan; do echo "- - -" > $h; done

   2. Ensure the drive has been recognized (check the dmesg logs, run lsblk etc.) and enjoy it!
2. A more "aggressive" method
   (note: some old SATA controller made by VIA Technologies and managed by sata_via kernel driver is used here for sample purposes; should work with any recent 2.6+ Linux kernel versions):
   0. To prevent any data loss, flush caches & unmount all the mounted partitions for all the drives connected to any VIA SATA controller(s) installed on the affected system!
   1. Remove the kernel driver module (verbosity is helpful sometimes):

      # modprobe -v -r sata_via

   2. Physically attach (or detach) any drives to the VIA SATA controller.
   3. Re-insert the kernel module:

      # modprobe -v sata_via

   4. Enjoy!

References:

1. Scanning Storage Interconnects - RHEL7 Storage Administration Guide

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Last updated: 2014-06-20