How do I choose the right parameters when using badblocks?
Since your drive has a 4096 byte physical sector size, you want to use -b 4096
. I don't think the -c argument makes much difference, so just leave it alone.
Also the drive's internal SMART test is better and faster than badblocks, so using smartmontools or the disk utility to run that instead is a better idea.
I have created a benchmark tool to test different settings. The test may take long time and remove your data, so please use with care.
badblocks_benchmark.sh:
#!/bin/bash
blocks=4194304 # 2^22, must be dividable by 2^8 (max i) = 256
block_size=512
result=""
for i in {1..8}
do
block_count=1
for j in {1..18}
do
echo -n "Benchmark with block count: $block_count, block size: $block_size: "
execution_time=`/usr/bin/time 2>&1 -f "%Es" badblocks >/dev/null -w -b $block_size -c $block_count -t random $1 $blocks`
status=$?
if [ $status -eq 0 ]; then
result=`echo -e "$result""\n""$execution_time: badblocks -b $block_size -c $block_count"`
echo "$execution_time"
fi
block_count=$(( $block_count * 2 ))
done
block_size=$(( $block_size * 2 ))
blocks=$(( $blocks / 2 ))
done
echo "Result:"
echo "$result" | sort --numeric-sort
You can use it as:
./badblocks_benchmark.sh /dev/sdX
If you want to benchmark with only 4k blocks then:
#!/bin/bash
blocks=4194304 # 2^22, you can use any 2^x number
block_size=4096
result=""
block_count=1
for j in {1..18}
do
echo -n "Benchmark with block count: $block_count, block size: $block_size: "
execution_time=`/usr/bin/time 2>&1 -f "%Es" badblocks >/dev/null -w -b $block_size -c $block_count -t random $1 $blocks`
status=$?
if [ $status -eq 0 ]; then
result=`echo -e "$result""\n""$execution_time: badblocks -b $block_size -c $block_count"`
echo "$execution_time"
fi
block_count=$(( $block_count * 2 ))
done
echo "Result:"
echo "$result" | sort --numeric-sort
Based on my benchmarks the using only -b 4096 without -c (default 64) is pretty good.
My results (smaller is better): Execution time in seconds and arguments
0:28.50s: badblocks -b 1024 -c 512
0:28.50s: badblocks -b 4096 -c 1024
0:28.50s: badblocks -b 512 -c 1024
0:28.50s: badblocks -b 65536 -c 8
0:28.51s: badblocks -b 2048 -c 1024
0:28.51s: badblocks -b 32768 -c 16
0:28.51s: badblocks -b 65536 -c 128
0:28.51s: badblocks -b 65536 -c 64
0:28.52s: badblocks -b 32768 -c 128
0:28.52s: badblocks -b 65536 -c 4
0:28.52s: badblocks -b 8192 -c 64
0:28.53s: badblocks -b 16384 -c 512
0:28.53s: badblocks -b 16384 -c 8
0:28.53s: badblocks -b 32768 -c 32
0:28.53s: badblocks -b 32768 -c 4
0:28.53s: badblocks -b 32768 -c 64
0:28.53s: badblocks -b 65536 -c 16
0:28.53s: badblocks -b 8192 -c 512
0:28.54s: badblocks -b 4096 -c 256
0:28.54s: badblocks -b 4096 -c 32
0:28.54s: badblocks -b 4096 -c 64
0:28.54s: badblocks -b 8192 -c 128
0:28.55s: badblocks -b 1024 -c 1024
0:28.55s: badblocks -b 1024 -c 256
0:28.55s: badblocks -b 16384 -c 256
0:28.55s: badblocks -b 2048 -c 128
0:28.55s: badblocks -b 2048 -c 64
0:28.55s: badblocks -b 32768 -c 8
0:28.55s: badblocks -b 4096 -c 16
0:28.55s: badblocks -b 512 -c 2048
0:28.55s: badblocks -b 512 -c 256
0:28.55s: badblocks -b 65536 -c 1
0:28.55s: badblocks -b 8192 -c 1024
0:28.55s: badblocks -b 8192 -c 16
0:28.55s: badblocks -b 8192 -c 256
0:28.55s: badblocks -b 8192 -c 32
0:28.56s: badblocks -b 2048 -c 2048
0:28.56s: badblocks -b 512 -c 512
0:28.57s: badblocks -b 1024 -c 64
0:28.57s: badblocks -b 16384 -c 128
0:28.57s: badblocks -b 16384 -c 4
0:28.57s: badblocks -b 16384 -c 64
0:28.57s: badblocks -b 2048 -c 512
0:28.57s: badblocks -b 2048 -c 8192
0:28.57s: badblocks -b 32768 -c 256
0:28.57s: badblocks -b 4096 -c 128
0:28.57s: badblocks -b 4096 -c 2048
0:28.57s: badblocks -b 512 -c 16384
0:28.57s: badblocks -b 65536 -c 32
0:28.57s: badblocks -b 65536 -c 65536
0:28.57s: badblocks -b 8192 -c 8
0:28.58s: badblocks -b 1024 -c 2048
0:28.58s: badblocks -b 1024 -c 4096
0:28.58s: badblocks -b 16384 -c 16
0:28.58s: badblocks -b 2048 -c 4096
0:28.58s: badblocks -b 4096 -c 512
0:28.58s: badblocks -b 65536 -c 131072
0:28.59s: badblocks -b 1024 -c 8192
0:28.59s: badblocks -b 2048 -c 256
0:28.59s: badblocks -b 2048 -c 32
0:28.59s: badblocks -b 32768 -c 2
0:28.60s: badblocks -b 1024 -c 128
0:28.60s: badblocks -b 1024 -c 16384
0:28.60s: badblocks -b 512 -c 4096
0:28.60s: badblocks -b 65536 -c 2
0:28.62s: badblocks -b 16384 -c 32
0:28.62s: badblocks -b 512 -c 128
0:28.62s: badblocks -b 512 -c 32768
0:28.63s: badblocks -b 512 -c 8192
0:28.65s: badblocks -b 4096 -c 4096
0:28.67s: badblocks -b 16384 -c 1024
0:28.79s: badblocks -b 8192 -c 2048
0:28.80s: badblocks -b 8192 -c 4
0:28.81s: badblocks -b 16384 -c 2048
0:28.83s: badblocks -b 32768 -c 512
0:28.86s: badblocks -b 65536 -c 512
0:28.89s: badblocks -b 2048 -c 16384
0:28.98s: badblocks -b 65536 -c 256
0:29.09s: badblocks -b 8192 -c 4096
0:29.10s: badblocks -b 4096 -c 8192
0:29.10s: badblocks -b 512 -c 65536
0:29.15s: badblocks -b 1024 -c 32768
0:29.15s: badblocks -b 32768 -c 1024
0:29.34s: badblocks -b 4096 -c 8
0:29.35s: badblocks -b 1024 -c 32
0:29.40s: badblocks -b 16384 -c 2
0:29.41s: badblocks -b 32768 -c 1
0:29.41s: badblocks -b 512 -c 64
0:29.45s: badblocks -b 32768 -c 131072
0:29.46s: badblocks -b 2048 -c 16
0:30.10s: badblocks -b 2048 -c 32768
0:30.13s: badblocks -b 1024 -c 65536
0:30.14s: badblocks -b 16384 -c 4096
0:30.16s: badblocks -b 4096 -c 16384
0:30.16s: badblocks -b 512 -c 131072
0:30.22s: badblocks -b 8192 -c 8192
0:30.23s: badblocks -b 65536 -c 1024
0:30.26s: badblocks -b 32768 -c 2048
0:30.38s: badblocks -b 1024 -c 131072
0:30.38s: badblocks -b 2048 -c 65536
0:30.49s: badblocks -b 4096 -c 32768
0:30.50s: badblocks -b 65536 -c 2048
0:30.50s: badblocks -b 8192 -c 16384
0:30.53s: badblocks -b 32768 -c 4096
0:30.64s: badblocks -b 16384 -c 8192
0:31.01s: badblocks -b 2048 -c 131072
0:31.13s: badblocks -b 32768 -c 8192
0:31.14s: badblocks -b 65536 -c 4096
0:31.17s: badblocks -b 16384 -c 16384
0:31.17s: badblocks -b 4096 -c 65536
0:31.17s: badblocks -b 8192 -c 32768
0:32.20s: badblocks -b 4096 -c 131072
0:32.20s: badblocks -b 65536 -c 8192
0:32.21s: badblocks -b 8192 -c 65536
0:32.24s: badblocks -b 32768 -c 16384
0:32.25s: badblocks -b 16384 -c 32768
0:34.42s: badblocks -b 8192 -c 131072
0:34.57s: badblocks -b 16384 -c 65536
0:34.61s: badblocks -b 32768 -c 32768
0:34.71s: badblocks -b 65536 -c 16384
0:39.08s: badblocks -b 4096 -c 4
0:39.23s: badblocks -b 1024 -c 16
0:39.39s: badblocks -b 8192 -c 2
0:39.56s: badblocks -b 16384 -c 1
0:39.60s: badblocks -b 2048 -c 8
0:39.69s: badblocks -b 512 -c 32
1:02.34s: badblocks -b 1024 -c 8
1:02.45s: badblocks -b 4096 -c 2
1:02.50s: badblocks -b 512 -c 16
1:02.57s: badblocks -b 2048 -c 4
1:03.64s: badblocks -b 8192 -c 1
1:10.68s: badblocks -b 512 -c 4
1:10.69s: badblocks -b 1024 -c 2
1:11.07s: badblocks -b 2048 -c 1
1:14.60s: badblocks -b 512 -c 2
1:15.02s: badblocks -b 1024 -c 1
1:22.85s: badblocks -b 512 -c 1
1:47.08s: badblocks -b 1024 -c 4
1:47.21s: badblocks -b 4096 -c 1
1:47.49s: badblocks -b 2048 -c 2
1:47.96s: badblocks -b 512 -c 8