In computing, the kernel is the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources (the communication between hardware and software ...
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20answers
10k views
rm on a directory with millions of files
Background: physical server, about two years old, 7200-RPM SATA drives connected to a 3Ware RAID card, ext3 FS mounted noatime and data=ordered, not under crazy load, kernel 2.6.18-92.1.22.el5, uptime ...
18
votes
3answers
12k views
Turn off the Linux OOM killer by default?
The OOM killer on Linux wreaks havoc with various applications every so often, and it appears that not much is really done on the kernel development side to improve this. Would it not be better, as a ...
3
votes
2answers
5k views
Linux Kernel crash mutex_lock_slowpath “blocked for more than 120 seconds”. What to do?
I have out-of-the box Debian Lenny with non-custom kernel 2.6.26-2-amd64.
Brand new server that is used to 5% of it's potential, CPU and Disk-wise.
Meaning it probably not crashing because of ...
1
vote
4answers
405 views
ps aux as non-root doesn't show all processes
i'm using an ubuntu 10.04 server...
when i run ps aux as root i see all processes when i run ps aux as nonroot i see JUST the processes of the current user
after a bit of research i found the ...
4
votes
3answers
3k views
Interpreting cryptic kernel “page allocation failure” messages
I have a multi-user CentOS 6.1 database system running an application named ABC. The server is 64-bit, 8GB RAM and 6 vCPU (on VMWare ESXi 4). We get frequent dumps into the dmesg and the system logs ...
3
votes
4answers
617 views
Reloading a kernel “live” in CentOS / RHEL 6
When upgrading the kernel package on CentOS or RHEL 6, is it possible to load the new kernel without rebooting?
My gut tells me it's not, but if it were, it'd be handy - especially when compiling ...
2
votes
1answer
622 views
Under what circumstances will Linux ignore the route table when choosing the MAC address for an outbound frame?
While debugging a problem with the networking configuration for a set of virtual machines running under KVM, I discovered a circumstance where the kernel in the guest VM has decided to stamp the ...
1
vote
1answer
190 views
Kernel Errors Present: EXT4-fs
Logwatch is giving me the following error:
WARNING: Kernel Errors Present
EXT4-fs (sda1): error count: 4 ...: 1 Time(s)
EXT4-fs (sda1): initial error at 1350482172: e ...: 1 Time(s)
EXT4-fs ...
0
votes
3answers
4k views
How long does it take to fsck a volume?
We are running website which is currently serving 3-5 million page views. Our site is file sharing site and so it contains 250,000 files and few thousand symbolic links.
The hard disk is a 1500GB ...
0
votes
1answer
632 views
How do i view / enable kernel logs on an ec2 instance (amazon linux)?
I've got a amazon ec2 server that i'm playing around with TCP settings in the sysctl.conf to increase the number of concurrent TCP connections it can handle, and i want to be able to view the kernel ...
4
votes
3answers
3k views
Kernel Log “TCP: Treason uncloaked!”
On one linux server (Gentoo hardened), we are experiencing bursts of the following messages in dmesg from time to time:
TCP: Treason uncloaked! Peer xx.xx.xxx.xxx:65039/80 shrinks window ...
4
votes
3answers
241 views
Compiling kernel version >= 2.6.34 on CentOS 5: RAID set “ddf1_foo” was not activated?
I want to mount a Ceph FS on some CentOS 5 servers. Since the ceph-fuse failed with below errors:
# ceph-fuse --no-fuse-big-writes -m 192.168.2.15:6789 /mnt/ceph/
ceph-fuse[7528]: starting ceph ...
2
votes
4answers
7k views
possible SYN flooding on port 80. Sending cookies
I recently had a server downtime. I looked everywhere and the only thing I found in my log files is:
Feb 17 18:58:04 localhost kernel: possible SYN flooding on port 80. Sending cookies.
Feb 17 ...
8
votes
8answers
2k views
Rebooting servers for kernel updates
I have a few production Fedora and Debian webservers that host our sites as well as user shell accounts (used for git vcs work, some screen+irssi sessions, etc).
Occasionally a new kernel update will ...
4
votes
2answers
8k views
How do I upgrade the kernel in Ubuntu Server 10.04?
I'm running Ubuntu Server 10.04 LTS. When I login I see the message:
39 packages can be updated.
18 updates are security updates.
The usual formula of
sudo apt-get update
sudo apt-get upgrade
...
1
vote
1answer
528 views
Unable to mount fat drive in linux
This is sort of a continuation from How to mount a .bin image file in linux but it morphed into a different problem altogether, so I figured I'd ask a new question with the relevant info rather than ...
3
votes
3answers
1k views
how do I convert a live root ext3 filesystem to ext4?
I have a root filesystem thats live and mounted and I'd like to convert it to ext4. All the howto's i've read deal with booting off a live CD but thats not an option.
2
votes
1answer
124 views
overriding default scheduler for blkio requests in cgroups
I am trying to optimize a set of servers that have to reside on single machine. i.e. i can have multiple application server, a DB server and of course a samba server as well in same instance. Now I ...
2
votes
3answers
2k views
Compiling realtime kernel from RHEL 6 MRG sources on CentOS 6
I'm trying to compile kernel-rt-2.6.33.9-rt31.75.el6rt.src.rpm from RHEL6 MRG source RPMs on Centos 6 x86_64 system.
It's first time I'm doing this, so I did research on how to do this properly. From ...
1
vote
2answers
816 views
Log - Server kernel: INFO: task httpd:000000 blocked for more than 120 seconds
Almost everyday my server is crashing due to hight server load, and even restarting apache or mysql can't solve the problem. I need to reboot the server to solve, or it crash again due to the high ...
1
vote
2answers
220 views
Error: Can't alloc conntrack
What does the message in kernel.log:
nf_conntrack_alloc: Can't alloc conntrack
0
votes
2answers
591 views
Compiling linux kernel - `make install` asks for LILO. Now what?
So I am following this guide to compile my custom kernel - http://library.linode.com/linode-platform/custom-instances/pv-grub-custom-compiled-kernel#sph_compile-and-install-the-kernel
So far so good, ...
0
votes
2answers
750 views
Kernel update without reboot [duplicate]
Possible Duplicate:
Reloading a kernel “live” in CentOS / RHEL 6
How can i update kernel on Centos without reboot .?
I found ksplice but it is not supported for Centos.
...
0
votes
1answer
658 views
Xen Kernel on Debian Squeeze making 1GB memory 'absent'
Possible Duplicate:
Fresh Debian Squeeze (6) Installation - Very High Ram Usage
We have a Dell Poweredge R210 server with 8GB of installed RAM. This is a fresh install of Debian Squeeze, ...
