Editing Dd (command)
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:<code>oflag=sync</code><ref>https://www.gnu.org/software/coreutils/manual/html_node/dd-invocation.html#dd-invocation</ref> | :<code>oflag=sync</code><ref>https://www.gnu.org/software/coreutils/manual/html_node/dd-invocation.html#dd-invocation</ref> | ||
:<code>iflag=[fullblock|nocache]</code> | :<code>iflag=[fullblock|nocache]</code> | ||
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== Examples == | == Examples == | ||
* Write a 10G file with random data: 10 G (<code>bs=10G count=1</code>), with random data (<code>[[/dev]]/[[urandom]]</code>)<ref>https://superuser.com/a/470957</ref>: | * Write a 10G file with random data: 10 G (<code>bs=10G count=1</code>), with random data (<code>[[/dev]]/[[urandom]]</code>)<ref>https://superuser.com/a/470957</ref>: | ||
| − | <code>dd iflag=fullblock if=/dev/[[urandom]] of=sample_output_file.txt bs=10G count=1 status= | + | <code>dd iflag=fullblock if=/dev/[[urandom]] of=sample_output_file.txt bs=10G count=1 status=progress</code> |
<pre> | <pre> | ||
10737418240 bytes (11 GB, 10 GiB) copied, 66 s, 162 MB/s | 10737418240 bytes (11 GB, 10 GiB) copied, 66 s, 162 MB/s | ||
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10737418240 bytes (11 GB, 10 GiB) copied, 66.4367 s, 162 MB/s | 10737418240 bytes (11 GB, 10 GiB) copied, 66.4367 s, 162 MB/s | ||
</pre> | </pre> | ||
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| − | * Write a 10G with zeroes: 10 G (<code>bs=10G count=1</code>), file with "zeroes" (<code> | + | * Write a 10G with zeroes: 10 G (<code>bs=10G count=1</code>), file with "zeroes" (<code>/dev/zero</code>): |
<code>dd iflag=fullblock if=[[/dev/zero]] of=sample_output_file.txt bs=10G count=1 status=progress</code> | <code>dd iflag=fullblock if=[[/dev/zero]] of=sample_output_file.txt bs=10G count=1 status=progress</code> | ||
<pre> | <pre> | ||
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dd: memory exhausted by input buffer of size 10737418240 bytes (10 GiB) | dd: memory exhausted by input buffer of size 10737418240 bytes (10 GiB) | ||
</pre> | </pre> | ||
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== Activities == | == Activities == | ||
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Advanced | Advanced | ||
| − | # Understand iflags, such us | + | # Understand iflags, such us fullblock <code>iflag=fullblock</code> meaning |
# Try to interrupt/kill your command: <code>dd iflag=fullblock if=/dev/urandom of=sample_output_file.txt bs=10G count=1</code> and explain outcome. | # Try to interrupt/kill your command: <code>dd iflag=fullblock if=/dev/urandom of=sample_output_file.txt bs=10G count=1</code> and explain outcome. | ||
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== See also == | == See also == | ||
| − | * | + | * [[cp]] and [[rsync]] |
* {{Io performance commands}} | * {{Io performance commands}} | ||
| − | * | + | * [[pv]] |
* [[Benchmarking tools]] | * [[Benchmarking tools]] | ||
* {{files}} | * {{files}} | ||
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