How to append data in a file by dd?
I want to append new data in a file stored in SSD.
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append
But df -h shows the dd command always overwrite the test file, instead appends new data in the test file.
I also tried
dd if=/dev/shm/test of=/data/sdb/test bs=1G conv=notrunc
It does not work, either.
unix ssd dd
asked Dec 9 '14 at 5:52
city
193116
add a comment |
I want to append new data in a file stored in SSD.
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append
But df -h shows the dd command always overwrite the test file, instead appends new data in the test file.
I also tried
dd if=/dev/shm/test of=/data/sdb/test bs=1G conv=notrunc
It does not work, either.
unix ssd dd
asked Dec 9 '14 at 5:52
city
193116
add a comment |
I want to append new data in a file stored in SSD.
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append
But df -h shows the dd command always overwrite the test file, instead appends new data in the test file.
I also tried
dd if=/dev/shm/test of=/data/sdb/test bs=1G conv=notrunc
It does not work, either.
unix ssd dd
asked Dec 9 '14 at 5:52
city
193116
I want to append new data in a file stored in SSD.
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append
But df -h shows the dd command always overwrite the test file, instead appends new data in the test file.
I also tried
dd if=/dev/shm/test of=/data/sdb/test bs=1G conv=notrunc
It does not work, either.
unix ssd dd
unix ssd dd
asked Dec 9 '14 at 5:52
city
193116
asked Dec 9 '14 at 5:52
city
193116
asked Dec 9 '14 at 5:52
city
193116
asked Dec 9 '14 at 5:52
city
193116
asked Dec 9 '14 at 5:52
city
193116
193116
add a comment |
add a comment |
4 Answers
4
active
oldest
votes
What about:
dd if=/dev/shm/test bs=1G >>/data/sdb/test
answered Dec 9 '14 at 5:55
mdpc
3,81532033
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
add a comment |
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append conv=notrunc
That is what I think you should have used.
REF : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=373736
answered Dec 9 '14 at 7:16
Charm_quark
675514
1
Withoutcount=1option it appends all available space.
– mixel
Jan 29 '17 at 17:21
add a comment |
In Linux kernel 4.1 FALLOC_FL_INSERT_RANGE option was added. From fallocate(2) man page:
Specifying the FALLOC_FL_INSERT_RANGE flag (available since Linux 4.1)
in mode increases the file space by inserting a hole within the file
size without overwriting any existing data. The hole will start at
offset and continue for len bytes. When inserting the hole inside
file, the contents of the file starting at offset will be shifted
upward (i.e., to a higher file offset) by len bytes. Inserting a hole
inside a file increases the file size by len bytes.
And recently this option support was added to util-linux:
-i, --insert-range
Insert a hole of length bytes from offset, shifting existing
data.
So when util-linux version 2.30 will be released and your linux distro will update to this version we will be able to increase file size in a flash by running:
fallocate -i -l 1G -o 128M /path/to/file
where 128M is the current file size.
answered Jan 29 '17 at 18:15
mixel
22637
add a comment |
There is an easier way to append a sparse hole to a file.
truncateis much faster than dd. To grow the file with 10 bytes use:
truncate -s +10 file.txt
answer found in:
https://serverfault.com/a/343726/70242
answered Dec 19 '18 at 19:38
akostadinov
845918
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
What about:
dd if=/dev/shm/test bs=1G >>/data/sdb/test
answered Dec 9 '14 at 5:55
mdpc
3,81532033
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
add a comment |
What about:
dd if=/dev/shm/test bs=1G >>/data/sdb/test
answered Dec 9 '14 at 5:55
mdpc
3,81532033
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
add a comment |
What about:
dd if=/dev/shm/test bs=1G >>/data/sdb/test
answered Dec 9 '14 at 5:55
mdpc
3,81532033
What about:
dd if=/dev/shm/test bs=1G >>/data/sdb/test
answered Dec 9 '14 at 5:55
mdpc
3,81532033
answered Dec 9 '14 at 5:55
mdpc
3,81532033
answered Dec 9 '14 at 5:55
mdpc
3,81532033
answered Dec 9 '14 at 5:55
mdpc
3,81532033
3,81532033
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
add a comment |
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
your solution works. Thanks. But do you know why my solutions don't work? I have checked the man page. cannot find the reason. thanks.
– city
Dec 9 '14 at 6:46
add a comment |
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append conv=notrunc
That is what I think you should have used.
REF : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=373736
answered Dec 9 '14 at 7:16
Charm_quark
675514
1
Withoutcount=1option it appends all available space.
– mixel
Jan 29 '17 at 17:21
add a comment |
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append conv=notrunc
That is what I think you should have used.
REF : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=373736
answered Dec 9 '14 at 7:16
Charm_quark
675514
1
Withoutcount=1option it appends all available space.
– mixel
Jan 29 '17 at 17:21
add a comment |
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append conv=notrunc
That is what I think you should have used.
REF : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=373736
answered Dec 9 '14 at 7:16
Charm_quark
675514
dd if=/dev/shm/test of=/data/sdb/test bs=1G oflag=append conv=notrunc
That is what I think you should have used.
REF : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=373736
answered Dec 9 '14 at 7:16
Charm_quark
675514
answered Dec 9 '14 at 7:16
Charm_quark
675514
answered Dec 9 '14 at 7:16
Charm_quark
675514
answered Dec 9 '14 at 7:16
Charm_quark
675514
675514
1
Withoutcount=1option it appends all available space.
– mixel
Jan 29 '17 at 17:21
add a comment |
1
Withoutcount=1option it appends all available space.
– mixel
Jan 29 '17 at 17:21
1
1
Without
count=1 option it appends all available space.– mixel
Jan 29 '17 at 17:21
Without
count=1 option it appends all available space.– mixel
Jan 29 '17 at 17:21
add a comment |
In Linux kernel 4.1 FALLOC_FL_INSERT_RANGE option was added. From fallocate(2) man page:
Specifying the FALLOC_FL_INSERT_RANGE flag (available since Linux 4.1)
in mode increases the file space by inserting a hole within the file
size without overwriting any existing data. The hole will start at
offset and continue for len bytes. When inserting the hole inside
file, the contents of the file starting at offset will be shifted
upward (i.e., to a higher file offset) by len bytes. Inserting a hole
inside a file increases the file size by len bytes.
And recently this option support was added to util-linux:
-i, --insert-range
Insert a hole of length bytes from offset, shifting existing
data.
So when util-linux version 2.30 will be released and your linux distro will update to this version we will be able to increase file size in a flash by running:
fallocate -i -l 1G -o 128M /path/to/file
where 128M is the current file size.
answered Jan 29 '17 at 18:15
mixel
22637
add a comment |
In Linux kernel 4.1 FALLOC_FL_INSERT_RANGE option was added. From fallocate(2) man page:
Specifying the FALLOC_FL_INSERT_RANGE flag (available since Linux 4.1)
in mode increases the file space by inserting a hole within the file
size without overwriting any existing data. The hole will start at
offset and continue for len bytes. When inserting the hole inside
file, the contents of the file starting at offset will be shifted
upward (i.e., to a higher file offset) by len bytes. Inserting a hole
inside a file increases the file size by len bytes.
And recently this option support was added to util-linux:
-i, --insert-range
Insert a hole of length bytes from offset, shifting existing
data.
So when util-linux version 2.30 will be released and your linux distro will update to this version we will be able to increase file size in a flash by running:
fallocate -i -l 1G -o 128M /path/to/file
where 128M is the current file size.
answered Jan 29 '17 at 18:15
mixel
22637
add a comment |
In Linux kernel 4.1 FALLOC_FL_INSERT_RANGE option was added. From fallocate(2) man page:
Specifying the FALLOC_FL_INSERT_RANGE flag (available since Linux 4.1)
in mode increases the file space by inserting a hole within the file
size without overwriting any existing data. The hole will start at
offset and continue for len bytes. When inserting the hole inside
file, the contents of the file starting at offset will be shifted
upward (i.e., to a higher file offset) by len bytes. Inserting a hole
inside a file increases the file size by len bytes.
And recently this option support was added to util-linux:
-i, --insert-range
Insert a hole of length bytes from offset, shifting existing
data.
So when util-linux version 2.30 will be released and your linux distro will update to this version we will be able to increase file size in a flash by running:
fallocate -i -l 1G -o 128M /path/to/file
where 128M is the current file size.
answered Jan 29 '17 at 18:15
mixel
22637
In Linux kernel 4.1 FALLOC_FL_INSERT_RANGE option was added. From fallocate(2) man page:
Specifying the FALLOC_FL_INSERT_RANGE flag (available since Linux 4.1)
in mode increases the file space by inserting a hole within the file
size without overwriting any existing data. The hole will start at
offset and continue for len bytes. When inserting the hole inside
file, the contents of the file starting at offset will be shifted
upward (i.e., to a higher file offset) by len bytes. Inserting a hole
inside a file increases the file size by len bytes.
And recently this option support was added to util-linux:
-i, --insert-range
Insert a hole of length bytes from offset, shifting existing
data.
So when util-linux version 2.30 will be released and your linux distro will update to this version we will be able to increase file size in a flash by running:
fallocate -i -l 1G -o 128M /path/to/file
where 128M is the current file size.
answered Jan 29 '17 at 18:15
mixel
22637
answered Jan 29 '17 at 18:15
mixel
22637
answered Jan 29 '17 at 18:15
mixel
22637
answered Jan 29 '17 at 18:15
mixel
22637
22637
add a comment |
add a comment |
There is an easier way to append a sparse hole to a file.
truncateis much faster than dd. To grow the file with 10 bytes use:
truncate -s +10 file.txt
answer found in:
https://serverfault.com/a/343726/70242
answered Dec 19 '18 at 19:38
akostadinov
845918
add a comment |
There is an easier way to append a sparse hole to a file.
truncateis much faster than dd. To grow the file with 10 bytes use:
truncate -s +10 file.txt
answer found in:
https://serverfault.com/a/343726/70242
answered Dec 19 '18 at 19:38
akostadinov
845918
add a comment |
There is an easier way to append a sparse hole to a file.
truncateis much faster than dd. To grow the file with 10 bytes use:
truncate -s +10 file.txt
answer found in:
https://serverfault.com/a/343726/70242
answered Dec 19 '18 at 19:38
akostadinov
845918
There is an easier way to append a sparse hole to a file.
truncateis much faster than dd. To grow the file with 10 bytes use:
truncate -s +10 file.txt
answer found in:
https://serverfault.com/a/343726/70242
answered Dec 19 '18 at 19:38
akostadinov
845918
answered Dec 19 '18 at 19:38
akostadinov
845918
answered Dec 19 '18 at 19:38
akostadinov
845918
answered Dec 19 '18 at 19:38
akostadinov
845918
845918
add a comment |
add a comment |
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