ber_flush2 - Linux


ber_flush2 is a command-line utility used to flush buffers associated with block devices. It’s particularly useful for ensuring data consistency and preventing data loss in scenarios where data is written to a block device but not yet physically committed to the storage medium (e.g., solid-state drives).


ber_flush2 [-f] [-v] [-i] device [sector-start sector-end]


  • -f: Force flush operation. This option is useful when the kernel is unresponsive or the flush operation is blocked. Use with caution.
  • -v: Verbose mode. Provides detailed information about the flush operation.
  • -i: Ignore errors. The command will continue flushing even if errors occur.


Flush the entire /dev/sda device:

ber_flush2 /dev/sda

Flush a specific range of sectors (100-200) on /dev/sdb:

ber_flush2 /dev/sdb 100 200

Flush the entire /dev/sdc device forcefully:

ber_flush2 -f /dev/sdc

Common Issues

  • Permission denied: Ensure you have sufficient privileges to access the specified block device.
  • Invalid arguments: Double-check your syntax and make sure sector ranges are valid.


ber_flush2 can be integrated into scripts or automated processes to ensure data consistency. For instance, it can be used after data is written to a block device to guarantee its immediate commit to the storage medium.

Related Commands

  • blkdiscard – Discard data from a block device
  • hdparm – Hard disk parameter utility
  • fsync – Flush a file to disk