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11-28-2020 |
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DD - Disk
Duplication |
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DD command does the exact photo copy of
source to destination |
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Source sdb
8:16 0
16G 0 disk ├─sdb1
8:17 0 8G
0 part ├─sdb2
8:18 0 4G
0 part └─sdb3 8:19 0
2G 0 part |
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Destination sdf 8:80 0
40G 0 disk |
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[root@zmpt01 ~]# dd if=/dev/sdb of=/dev/sdf
The destination disk must be same size
or higher in capacity Disk Duplication is independent of file
system Example, you can disk duplicate a Windows
file system |
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33554432+0 records in # < ----Exact match of in and out 33554432+0 records out # < ----Exact match of in and out 17179869184 bytes (17 GB) copied,
608.854 s, 28.2 MB/s |
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sdb 8:16 0
16G 0 disk ├─sdb1
8:17 0 8G
0 part ├─sdb2
8:18 0 4G
0 part └─sdb3 8:19 0
2G 0 part /dev/sdb1:
UUID="47d30ab1-92ee-4dc8-8c79-ef9dd898e1f0" TYPE="ext4" /dev/sdb2:
UUID="e5a18729-daf6-4c7b-89db-3a5979d3c254" TYPE="xfs" /dev/sdb3:
UUID="7d459795-930e-4cc5-b737-a84b452ff04a" TYPE="swap" |
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Exact replica – even the UUID is
duplicated sdf 8:80 0
40G 0 disk ├─sdf1
8:81 0 8G
0 part ├─sdf2
8:82 0 4G
0 part └─sdf3 8:83
0 2G 0 part /dev/sdf1:
UUID="47d30ab1-92ee-4dc8-8c79-ef9dd898e1f0" TYPE="ext4" /dev/sdf2:
UUID="e5a18729-daf6-4c7b-89db-3a5979d3c254" TYPE="xfs" /dev/sdf3:
UUID="7d459795-930e-4cc5-b737-a84b452ff04a" TYPE="swap" |
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Create
Large file |
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[root@zmpt01 ~]# dd if=/dev/zero
of=zafar1 count=1 bs=2G 0+1 records in 0+1 records out 2147479552 bytes (2.1 GB) copied,
75.7903 s, 28.3 MB/s
[root@zmpt01 ~]# ls -ltrh total 2.0G -rw-r--r--. 1 root root 2.0G Nov 28
16:01 zafar1 Good for network t/s |
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Wipe the
disk |
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This is the lowest level of disk wipe [root@zmpt01 ~]# dd if=/dev/zero
of=/dev/sdb [root@zmpt01 ~]# dd if=/dev/zero
of=/dev/sdb dd: writing to ‘/dev/sdb’: No space
left on device 33554433+0 records in 33554432+0 records out 17179869184 bytes (17 GB) copied,
610.231 s, 28.2 MB/s |
