“echo 3 > /proc/sys/vm/drop_caches” - Permission denied as root
up vote
18
down vote
favorite
I am currently having some issues with the cache. It is a little too much right now so I wanted to clear it. I googled and found this little command: sync && echo 3 > /proc/sys/vm/drop_caches.
I am logged in as root over SSH (not using sudo). These are the attempts I made:
root@server: ~ # ll /proc/sys/vm/drop_caches
-rw-r--r-- 1 root root 0 15. Jan 20:21 /proc/sys/vm/drop_caches
root@server: ~ # echo 3 > /proc/sys/vm/drop_caches
-bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # sudo su -c "echo 3 > /proc/sys/vm/drop_caches"
bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # echo 3 | sudo tee /proc/sys/vm/drop_caches
tee: /proc/sys/vm/drop_caches: Permission denied
3
It is a remote machine running Debian. As far as I know there are some vCores in this machine and it uses Virtuozzo for the virtualization.
I really just want to clear the cache (So I can only access it using SSH).
I also tried registering this as a cronjob. But it simply fails too!
linux permissions virtualization proc openvz
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
|
show 5 more comments
up vote
18
down vote
favorite
I am currently having some issues with the cache. It is a little too much right now so I wanted to clear it. I googled and found this little command: sync && echo 3 > /proc/sys/vm/drop_caches.
I am logged in as root over SSH (not using sudo). These are the attempts I made:
root@server: ~ # ll /proc/sys/vm/drop_caches
-rw-r--r-- 1 root root 0 15. Jan 20:21 /proc/sys/vm/drop_caches
root@server: ~ # echo 3 > /proc/sys/vm/drop_caches
-bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # sudo su -c "echo 3 > /proc/sys/vm/drop_caches"
bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # echo 3 | sudo tee /proc/sys/vm/drop_caches
tee: /proc/sys/vm/drop_caches: Permission denied
3
It is a remote machine running Debian. As far as I know there are some vCores in this machine and it uses Virtuozzo for the virtualization.
I really just want to clear the cache (So I can only access it using SSH).
I also tried registering this as a cronjob. But it simply fails too!
linux permissions virtualization proc openvz
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
1
Are you running this as root or are you usingsudo?
– terdon♦
Jan 15 '14 at 19:52
2
I am running this as root. But sudo also fails.
– BrainStone
Jan 15 '14 at 19:53
Does not work either. Already tried it. Same error message.
– BrainStone
Jan 15 '14 at 19:55
See the slm's A on this question, it might help.
– Risto Salminen
Jan 15 '14 at 19:58
@terdon : Whoops. Retracted.
– goldilocks
Jan 15 '14 at 20:00
|
show 5 more comments
up vote
18
down vote
favorite
up vote
18
down vote
favorite
I am currently having some issues with the cache. It is a little too much right now so I wanted to clear it. I googled and found this little command: sync && echo 3 > /proc/sys/vm/drop_caches.
I am logged in as root over SSH (not using sudo). These are the attempts I made:
root@server: ~ # ll /proc/sys/vm/drop_caches
-rw-r--r-- 1 root root 0 15. Jan 20:21 /proc/sys/vm/drop_caches
root@server: ~ # echo 3 > /proc/sys/vm/drop_caches
-bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # sudo su -c "echo 3 > /proc/sys/vm/drop_caches"
bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # echo 3 | sudo tee /proc/sys/vm/drop_caches
tee: /proc/sys/vm/drop_caches: Permission denied
3
It is a remote machine running Debian. As far as I know there are some vCores in this machine and it uses Virtuozzo for the virtualization.
I really just want to clear the cache (So I can only access it using SSH).
I also tried registering this as a cronjob. But it simply fails too!
linux permissions virtualization proc openvz
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
I am currently having some issues with the cache. It is a little too much right now so I wanted to clear it. I googled and found this little command: sync && echo 3 > /proc/sys/vm/drop_caches.
I am logged in as root over SSH (not using sudo). These are the attempts I made:
root@server: ~ # ll /proc/sys/vm/drop_caches
-rw-r--r-- 1 root root 0 15. Jan 20:21 /proc/sys/vm/drop_caches
root@server: ~ # echo 3 > /proc/sys/vm/drop_caches
-bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # sudo su -c "echo 3 > /proc/sys/vm/drop_caches"
bash: /proc/sys/vm/drop_caches: Permission denied
root@server: ~ # echo 3 | sudo tee /proc/sys/vm/drop_caches
tee: /proc/sys/vm/drop_caches: Permission denied
3
It is a remote machine running Debian. As far as I know there are some vCores in this machine and it uses Virtuozzo for the virtualization.
I really just want to clear the cache (So I can only access it using SSH).
I also tried registering this as a cronjob. But it simply fails too!
linux permissions virtualization proc openvz
linux permissions virtualization proc openvz
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
edited Jun 30 '14 at 18:36
Tshepang
25.6k71182262
25.6k71182262
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
asked Jan 15 '14 at 19:42
BrainStone
1,14371941
1,14371941
1
Are you running this as root or are you usingsudo?
– terdon♦
Jan 15 '14 at 19:52
2
I am running this as root. But sudo also fails.
– BrainStone
Jan 15 '14 at 19:53
Does not work either. Already tried it. Same error message.
– BrainStone
Jan 15 '14 at 19:55
See the slm's A on this question, it might help.
– Risto Salminen
Jan 15 '14 at 19:58
@terdon : Whoops. Retracted.
– goldilocks
Jan 15 '14 at 20:00
|
show 5 more comments
1
Are you running this as root or are you usingsudo?
– terdon♦
Jan 15 '14 at 19:52
2
I am running this as root. But sudo also fails.
– BrainStone
Jan 15 '14 at 19:53
Does not work either. Already tried it. Same error message.
– BrainStone
Jan 15 '14 at 19:55
See the slm's A on this question, it might help.
– Risto Salminen
Jan 15 '14 at 19:58
@terdon : Whoops. Retracted.
– goldilocks
Jan 15 '14 at 20:00
1
1
Are you running this as root or are you using
sudo?– terdon♦
Jan 15 '14 at 19:52
Are you running this as root or are you using
sudo?– terdon♦
Jan 15 '14 at 19:52
2
2
I am running this as root. But sudo also fails.
– BrainStone
Jan 15 '14 at 19:53
I am running this as root. But sudo also fails.
– BrainStone
Jan 15 '14 at 19:53
Does not work either. Already tried it. Same error message.
– BrainStone
Jan 15 '14 at 19:55
Does not work either. Already tried it. Same error message.
– BrainStone
Jan 15 '14 at 19:55
See the slm's A on this question, it might help.
– Risto Salminen
Jan 15 '14 at 19:58
See the slm's A on this question, it might help.
– Risto Salminen
Jan 15 '14 at 19:58
@terdon : Whoops. Retracted.
– goldilocks
Jan 15 '14 at 20:00
@terdon : Whoops. Retracted.
– goldilocks
Jan 15 '14 at 20:00
|
show 5 more comments
6 Answers
6
active
oldest
votes
up vote
21
down vote
accepted
I am logged in as root over SSH...It is a remote machine running Debian.
Is it actually a remote machine, or a just a remote system? If this is a VPS slice somewhere, (at least some forms of) OS virtualization (e.g. openVZ) won't permit this from within the container. You don't run the machine, you just run your slice.
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
1
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
1
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
2
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
add a comment |
up vote
23
down vote
sudo has to cover whole redirection in order it can be completely executed under root:
$ sudo sh -c “/usr/bin/echo 3 > /proc/sys/vm/drop_caches”
answered Aug 5 '14 at 6:50
rasty.g
35326
5
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
1
alternatively, you could use tee instead:echo 3 | sudo tee /proc/sys/vm/drop_caches
– mchid
Dec 23 '15 at 0:09
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
1
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
|
show 1 more comment
up vote
11
down vote
This is normal behavior under OS-level virtualization. This can only be executed by someone with root access to the hardware node.
With for example OpenVZ, you don't get your own kernel instance and as such, are restricted from performing commands like this.
All share the same page cache, so to drop caches of only your instance, the kernel must check if the page belongs to you and if the other instances aren't using this page too.
With another virtualization technique like KVM or Xen this might be working.
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
answered Jan 15 '14 at 20:14
chaos
35k773115
1
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
2
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
1
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
|
show 2 more comments
up vote
7
down vote
You can use echo piped to sudo tee to allow the proper permission needed when you need to echo as root.
echo 3 | sudo tee /proc/sys/vm/drop_caches
Use tee --help to list more options.
answered Jan 29 '17 at 16:59
mchid
8341917
add a comment |
up vote
0
down vote
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
This command work for me without /usr/bin/echo in mchid answer. It was giving error sh: 1: /usr/bin/echo: not found . So used only 'echo'
answered Oct 16 at 11:47
ascii_walker
1012
add a comment |
up vote
0
down vote
I had the same problem when I tried to use sudo like this:
sudo echo 1 > /proc/sys/vm/overcommit_memory
My solution was to temporarily switch to root. Obiously, that permission has to be enabled on your system:
1. "sudo su -" #temporarily switch to root user
2. echo 1 > /proc/sys/vm/overcommit_memory
3. exit # Exit as root.
answered Dec 4 at 16:31
thebiggestlebowski
1011
add a comment |
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6 Answers
6
active
oldest
votes
6 Answers
6
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
21
down vote
accepted
I am logged in as root over SSH...It is a remote machine running Debian.
Is it actually a remote machine, or a just a remote system? If this is a VPS slice somewhere, (at least some forms of) OS virtualization (e.g. openVZ) won't permit this from within the container. You don't run the machine, you just run your slice.
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
1
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
1
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
2
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
add a comment |
up vote
21
down vote
accepted
I am logged in as root over SSH...It is a remote machine running Debian.
Is it actually a remote machine, or a just a remote system? If this is a VPS slice somewhere, (at least some forms of) OS virtualization (e.g. openVZ) won't permit this from within the container. You don't run the machine, you just run your slice.
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
1
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
1
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
2
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
add a comment |
up vote
21
down vote
accepted
up vote
21
down vote
accepted
I am logged in as root over SSH...It is a remote machine running Debian.
Is it actually a remote machine, or a just a remote system? If this is a VPS slice somewhere, (at least some forms of) OS virtualization (e.g. openVZ) won't permit this from within the container. You don't run the machine, you just run your slice.
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
I am logged in as root over SSH...It is a remote machine running Debian.
Is it actually a remote machine, or a just a remote system? If this is a VPS slice somewhere, (at least some forms of) OS virtualization (e.g. openVZ) won't permit this from within the container. You don't run the machine, you just run your slice.
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
edited Jan 15 '14 at 20:12
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
answered Jan 15 '14 at 20:06
goldilocks
61.3k13150205
61.3k13150205
1
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
1
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
2
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
add a comment |
1
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
1
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
2
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
1
1
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
There is like no way???
– BrainStone
Jan 15 '14 at 20:09
1
1
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
Probably not, since there wouldn't be much point in not permitting it if there were alternate methods that worked.
– goldilocks
Jan 15 '14 at 20:11
2
2
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
@BrainStone - I use OpenVZ, it's not possible!
– slm♦
Jan 15 '14 at 21:42
add a comment |
up vote
23
down vote
sudo has to cover whole redirection in order it can be completely executed under root:
$ sudo sh -c “/usr/bin/echo 3 > /proc/sys/vm/drop_caches”
answered Aug 5 '14 at 6:50
rasty.g
35326
5
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
1
alternatively, you could use tee instead:echo 3 | sudo tee /proc/sys/vm/drop_caches
– mchid
Dec 23 '15 at 0:09
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
1
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
|
show 1 more comment
up vote
23
down vote
sudo has to cover whole redirection in order it can be completely executed under root:
$ sudo sh -c “/usr/bin/echo 3 > /proc/sys/vm/drop_caches”
answered Aug 5 '14 at 6:50
rasty.g
35326
5
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
1
alternatively, you could use tee instead:echo 3 | sudo tee /proc/sys/vm/drop_caches
– mchid
Dec 23 '15 at 0:09
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
1
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
|
show 1 more comment
up vote
23
down vote
up vote
23
down vote
sudo has to cover whole redirection in order it can be completely executed under root:
$ sudo sh -c “/usr/bin/echo 3 > /proc/sys/vm/drop_caches”
answered Aug 5 '14 at 6:50
rasty.g
35326
sudo has to cover whole redirection in order it can be completely executed under root:
$ sudo sh -c “/usr/bin/echo 3 > /proc/sys/vm/drop_caches”
answered Aug 5 '14 at 6:50
rasty.g
35326
edited Sep 14 '14 at 6:09
answered Aug 5 '14 at 6:50
rasty.g
35326
answered Aug 5 '14 at 6:50
rasty.g
35326
answered Aug 5 '14 at 6:50
rasty.g
35326
35326
5
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
1
alternatively, you could use tee instead:echo 3 | sudo tee /proc/sys/vm/drop_caches
– mchid
Dec 23 '15 at 0:09
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
1
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
|
show 1 more comment
5
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
1
alternatively, you could use tee instead:echo 3 | sudo tee /proc/sys/vm/drop_caches
– mchid
Dec 23 '15 at 0:09
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
1
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
5
5
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
this actually worked for me (with the right binary location for echo)
– orm
Nov 5 '14 at 19:59
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
in OpenVZ not work
– shilovk
Mar 3 '15 at 16:03
1
1
alternatively, you could use tee instead:
echo 3 | sudo tee /proc/sys/vm/drop_caches– mchid
Dec 23 '15 at 0:09
alternatively, you could use tee instead:
echo 3 | sudo tee /proc/sys/vm/drop_caches– mchid
Dec 23 '15 at 0:09
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
Working in an Azure VM. Thanks!
– lordcheeto
Feb 9 '16 at 6:52
1
1
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
@mchid, consider adding your comment as an answer. It also worked for me on Azure VM.
– Erik Shilts
Jan 26 '17 at 22:04
|
show 1 more comment
up vote
11
down vote
This is normal behavior under OS-level virtualization. This can only be executed by someone with root access to the hardware node.
With for example OpenVZ, you don't get your own kernel instance and as such, are restricted from performing commands like this.
All share the same page cache, so to drop caches of only your instance, the kernel must check if the page belongs to you and if the other instances aren't using this page too.
With another virtualization technique like KVM or Xen this might be working.
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
answered Jan 15 '14 at 20:14
chaos
35k773115
1
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
2
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
1
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
|
show 2 more comments
up vote
11
down vote
This is normal behavior under OS-level virtualization. This can only be executed by someone with root access to the hardware node.
With for example OpenVZ, you don't get your own kernel instance and as such, are restricted from performing commands like this.
All share the same page cache, so to drop caches of only your instance, the kernel must check if the page belongs to you and if the other instances aren't using this page too.
With another virtualization technique like KVM or Xen this might be working.
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
answered Jan 15 '14 at 20:14
chaos
35k773115
1
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
2
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
1
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
|
show 2 more comments
up vote
11
down vote
up vote
11
down vote
This is normal behavior under OS-level virtualization. This can only be executed by someone with root access to the hardware node.
With for example OpenVZ, you don't get your own kernel instance and as such, are restricted from performing commands like this.
All share the same page cache, so to drop caches of only your instance, the kernel must check if the page belongs to you and if the other instances aren't using this page too.
With another virtualization technique like KVM or Xen this might be working.
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
answered Jan 15 '14 at 20:14
chaos
35k773115
This is normal behavior under OS-level virtualization. This can only be executed by someone with root access to the hardware node.
With for example OpenVZ, you don't get your own kernel instance and as such, are restricted from performing commands like this.
All share the same page cache, so to drop caches of only your instance, the kernel must check if the page belongs to you and if the other instances aren't using this page too.
With another virtualization technique like KVM or Xen this might be working.
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
answered Jan 15 '14 at 20:14
chaos
35k773115
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
edited Jan 15 '14 at 22:06
terdon♦
127k31245422
127k31245422
answered Jan 15 '14 at 20:14
chaos
35k773115
answered Jan 15 '14 at 20:14
chaos
35k773115
answered Jan 15 '14 at 20:14
chaos
35k773115
35k773115
1
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
2
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
1
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
|
show 2 more comments
1
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
2
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
1
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
1
1
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
So I could/should/must contact my hoster to clear the cache for me? And how do I find out what "virtualisation technique" my system is on?
– BrainStone
Jan 15 '14 at 20:15
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
Yes, you may not come around this...
– chaos
Jan 15 '14 at 20:18
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
I am not shure if this is right. I am running some vm's at aws and Xen and i am able to drop_caches.
– user55518
Jan 15 '14 at 20:51
2
2
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
The difference is between OS virtualization (OpenVZ, LXC) and platform virtualization (QEMU, Xen), both of which have advantages and disavantages vs. the other.
– goldilocks
Jan 15 '14 at 21:52
1
1
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
@bersch Xen uses an own kernel for VMs. OpenVZ does not. You can think of OpenVZ like a better "chroot".
– Nils
Jan 20 '14 at 11:49
|
show 2 more comments
up vote
7
down vote
You can use echo piped to sudo tee to allow the proper permission needed when you need to echo as root.
echo 3 | sudo tee /proc/sys/vm/drop_caches
Use tee --help to list more options.
answered Jan 29 '17 at 16:59
mchid
8341917
add a comment |
up vote
7
down vote
You can use echo piped to sudo tee to allow the proper permission needed when you need to echo as root.
echo 3 | sudo tee /proc/sys/vm/drop_caches
Use tee --help to list more options.
answered Jan 29 '17 at 16:59
mchid
8341917
add a comment |
up vote
7
down vote
up vote
7
down vote
You can use echo piped to sudo tee to allow the proper permission needed when you need to echo as root.
echo 3 | sudo tee /proc/sys/vm/drop_caches
Use tee --help to list more options.
answered Jan 29 '17 at 16:59
mchid
8341917
You can use echo piped to sudo tee to allow the proper permission needed when you need to echo as root.
echo 3 | sudo tee /proc/sys/vm/drop_caches
Use tee --help to list more options.
answered Jan 29 '17 at 16:59
mchid
8341917
answered Jan 29 '17 at 16:59
mchid
8341917
answered Jan 29 '17 at 16:59
mchid
8341917
answered Jan 29 '17 at 16:59
mchid
8341917
8341917
add a comment |
add a comment |
up vote
0
down vote
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
This command work for me without /usr/bin/echo in mchid answer. It was giving error sh: 1: /usr/bin/echo: not found . So used only 'echo'
answered Oct 16 at 11:47
ascii_walker
1012
add a comment |
up vote
0
down vote
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
This command work for me without /usr/bin/echo in mchid answer. It was giving error sh: 1: /usr/bin/echo: not found . So used only 'echo'
answered Oct 16 at 11:47
ascii_walker
1012
add a comment |
up vote
0
down vote
up vote
0
down vote
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
This command work for me without /usr/bin/echo in mchid answer. It was giving error sh: 1: /usr/bin/echo: not found . So used only 'echo'
answered Oct 16 at 11:47
ascii_walker
1012
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
This command work for me without /usr/bin/echo in mchid answer. It was giving error sh: 1: /usr/bin/echo: not found . So used only 'echo'
answered Oct 16 at 11:47
ascii_walker
1012
answered Oct 16 at 11:47
ascii_walker
1012
answered Oct 16 at 11:47
ascii_walker
1012
answered Oct 16 at 11:47
ascii_walker
1012
1012
add a comment |
add a comment |
up vote
0
down vote
I had the same problem when I tried to use sudo like this:
sudo echo 1 > /proc/sys/vm/overcommit_memory
My solution was to temporarily switch to root. Obiously, that permission has to be enabled on your system:
1. "sudo su -" #temporarily switch to root user
2. echo 1 > /proc/sys/vm/overcommit_memory
3. exit # Exit as root.
answered Dec 4 at 16:31
thebiggestlebowski
1011
add a comment |
up vote
0
down vote
I had the same problem when I tried to use sudo like this:
sudo echo 1 > /proc/sys/vm/overcommit_memory
My solution was to temporarily switch to root. Obiously, that permission has to be enabled on your system:
1. "sudo su -" #temporarily switch to root user
2. echo 1 > /proc/sys/vm/overcommit_memory
3. exit # Exit as root.
answered Dec 4 at 16:31
thebiggestlebowski
1011
add a comment |
up vote
0
down vote
up vote
0
down vote
I had the same problem when I tried to use sudo like this:
sudo echo 1 > /proc/sys/vm/overcommit_memory
My solution was to temporarily switch to root. Obiously, that permission has to be enabled on your system:
1. "sudo su -" #temporarily switch to root user
2. echo 1 > /proc/sys/vm/overcommit_memory
3. exit # Exit as root.
answered Dec 4 at 16:31
thebiggestlebowski
1011
I had the same problem when I tried to use sudo like this:
sudo echo 1 > /proc/sys/vm/overcommit_memory
My solution was to temporarily switch to root. Obiously, that permission has to be enabled on your system:
1. "sudo su -" #temporarily switch to root user
2. echo 1 > /proc/sys/vm/overcommit_memory
3. exit # Exit as root.
answered Dec 4 at 16:31
thebiggestlebowski
1011
answered Dec 4 at 16:31
thebiggestlebowski
1011
answered Dec 4 at 16:31
thebiggestlebowski
1011
answered Dec 4 at 16:31
thebiggestlebowski
1011
1011
add a comment |
add a comment |
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1
Are you running this as root or are you using
sudo?– terdon♦
Jan 15 '14 at 19:52
2
I am running this as root. But sudo also fails.
– BrainStone
Jan 15 '14 at 19:53
Does not work either. Already tried it. Same error message.
– BrainStone
Jan 15 '14 at 19:55
See the slm's A on this question, it might help.
– Risto Salminen
Jan 15 '14 at 19:58
@terdon : Whoops. Retracted.
– goldilocks
Jan 15 '14 at 20:00