Speed up md raid rebuilds

turbo_md_rebuild.py

#!/usr/bin/env python

import argparse
import sys

MAX_FP = '/proc/sys/dev/raid/speed_limit_max'
MIN_FP = '/proc/sys/dev/raid/speed_limit_min'
MAX_DEFAULT=200000
MIN_DEFAULT=1000
MAX_TURBO = MAX_DEFAULT * 2
MIN_TURBO = MIN_DEFAULT * 50


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        '--enable',
        dest='enable',
        action='store_true',
        default=False)
    parser.add_argument(
        '--disable',
        dest='disable',
        action='store_true',
        default=False)
    args = parser.parse_args()

    if args.enable and args.disable:
        sys.stderr.write('you cannot enable and disable turbo at the same time\n')
        sys.exit(1)
    elif not args.enable and not args.disable:
        sys.stderr.write('doing nothing, use --enable or --disable\n')
        sys.exit(1)

    if args.enable:
        enable_turbo = True
    elif args.disable:
        enable_turbo = False

    with open(MAX_FP, 'w') as fd:
        if enable_turbo:
            fd.write(str(MAX_TURBO))
        else:
            fd.write(str(MAX_DEFAULT))

    with open(MIN_FP, 'w') as fd:
        if enable_turbo:
            fd.write(str(MIN_TURBO))
        else:
            fd.write(str(MIN_DEFAULT))

    if enable_turbo:
        sys.stdout.write('turbo rebuild enabled\n')
    else:
        sys.stdout.write('turbo rebuild disabled\n')


if __name__ == '__main__':
    main()