Hot answers tagged rhel6
131
IPTables isnt made for this kind of work, where lots and lots of packets need to be analyzed to make these decisions. IPTables is partly the answer though!
The real answer to this is the awesome and underused traffic control facilities in linux. Note that mucking around with this without knowing what is going on may lead to you losing network connectivity ...
8
Yes, the tool is called mock and it's in EPEL.
Typical usage:
rpmbuild -bs mypackage.spec
mock -r epel-6-x86_64 mypackage-0.1-1.src.rpm
This is actually the preferred way to build RPMs, precisely because it isolates the process from the system so that unexpected dependencies don't get pulled in.
You can modify the files in /etc/mock to have it pull in ...
6
Downgrading to an unsupported PHP version is likely to be (no surprise) unsupported.
Compiling from source, or finding someone who has packaged an RPM, are pretty much your only two options.
BIG IMPORTANT SECURITY NOTE
You probably do not need to use dl().
You should never need to use dl().
Despite what you may have been told, alternatives do exist to ...
6
Put them in /etc/sysconfig/network-scripts/ifcfg-eth0, with a 2 or 3 etc. after them, such as:
IPADDR2=192.0.2.48
NETMASK2=255.255.255.0
IPADDR3=192.0.2.49
NETMASK3=255.255.255.0
Unfortunately this seems to be undocumented (or I can't find it right now; it looks like Red Hat rearranged their web site yet again).
6
You really won't find support for something like this, as it's not something that will pass any sanity checks.
So, think about it a bit. Your computer needs to know the gateway address in order to reach other machines outside it's local subnet. So, if you have a subnet 10.0.1.0/24 and your machine is 10.0.1.12, it would be able to reach any machine from ...
6
Short Answer
Install the equivalent centos-release package from a centos downloads location; This will enable the CentOS package repos where you can do a yum update or a yum install gcc
Long(er) Answer
With respect to the other answers, I felt a slight more full answer could be given to your question.
In a strict sense, CentOS aims to be 100% binary ...
5
Mike,
there are generally a few sources of good guides out there for security hardening.
The DISA STIGs
The NSA SRGs
NIST
CIS Benchmarks
Vendor guidance
SANS
Books specific to hardening
At my work, we use a combination of the DISA STIGs, along with puppet for Linux. I'd be more likely to say that is inadequate and push for some of the recommendations ...
5
run uname -a see which kernel you have running, then use yum remove kernel- (one by one) to all BUT the one that you're running (also keep one extra in addition to the one that you're running just in case if you need to load older kernel for whatever reason)
5
XFS and EL6 have fallen into an ugly state... I've abandoned XFS on EL6 systems for the time being due to several upstream features/changes slipping into the Red Hat kernel...
This one was a surprise and caused some panic: Why are my XFS filesystems suddenly consuming more space and full of sparse files?
Since November 2012, the XFS version shipping in ...
5
I wouldn't run the upgrade process this way if you're planning to perform in-place transitions from EL5 to EL6. It's not an easy or clean process.
See: Why is it so difficult to upgrade between major versions of Red Hat and CentOS? and Upgrade CentOS 5.x to CentOS 6.x - tips and techniques
However, you have the right idea of testing this in a ...
4
Basic security tennet: Don't use black lists (i.e., look for things to forbid), as it is too easy to leave something out (and you won't find out until it is too late); use white lists (i.e., check what needs to be allowed), if you forget something you'll know soon enough.
In this particular case: Make a list of the software that is needed on the machine, ...
4
I'd go with the default ext4, if only because it has shown in practice that it can take quite a beating, and in case of trouble there will probably be much more expertise at hand.
Oh, and before wishing you good luck, don't believe what colored squares with missing pieces tell you on random Internet sites. They might be spouting nonsense, no, they are ...
4
CentOS is basically recompiled RHEL packages and you can easily install RHEL package on CentOS host. The version number and architecture have to match, of course.
BTW, for postgres we use packages from http://yum.postgresql.org/ on Scientific Linux (yet another RHEL clone).
4
Delete at least one of the old kernels, as alexus said.
Then:
Edit /etc/yum.conf and specify the limit of the number of kernel versions to keep. It's set to 5 by default, but your system seems to be capable of handling only two:
installonly_limit=2
Finally, complain to the VPS provider about the strange template. /boot is 500MB by default in a CentOS 6 ...
4
This can be accomplished by using group ACLs. Adding the following line to your common-auth file:
auth required pam_access.so
Will get it set up. You can then use a group (it can be LDAP) to set an explicit deny. Invert the meaning to get an explicit allow, which may be a better choice if you're not allowed to ever delete students.
-:ALL EXCEPT root ...
4
You can use the yum repolist to show which repos you have enabled, and hence where the package is coming from;
(also yum repolist -v, with the -v flag for really verbose description of your enabled repositories)
# yum repolist
Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
epel/metalink | 10 kB ...
4
Your options for creating filesystems are limited to those described in the kickstart documentation (in particular, the part, logvol, and raid commands). The assumption there is generally that you're happy with the default options when creating filesystems. If you need anything fancier, you'll need to use the %pre or %post section to call mkfs.xfs ...
4
Upgrading from 5.6 to 6.1 is a big step - you're probably running different versions of both apache, php, and perhaps a bytecode cache as well.
If you're using a bytecode cache (which I believe you should, with the kind of load you're describing), you should verify that it's working (I know apc has changed some configuration syntax between versions, for ...
4
It looks like you've encountered a bug in the version of the kernel included in RHEL. There was a thread about this problem on the Xen development email list last year:
http://old-list-archives.xen.org/archives/html/xen-devel/2010-11/msg00616.html
You should probably try rebooting your instance via the EC2 console or command line utilities.
Regarding the ...
4
Maybe this is somehow about ACPI/APIC or kernel clock? I bet kernel in RHEL 6.1 has gained dynamic ticks (or, "tickless kernel") compared to one in RHEL 5.7.
If you run iostat -x 1 at your host, does it report huge number of interrupts during the lag? Interrupt storms, even if rare nowadays, can cause those stalls. Then it might be about ACPI or APIC and ...
4
I ran into the same problem and was able to resolve it by manually updating the sed package:
rpm -Uvh ftp://ftp.ntua.gr/pub/linux/scientificlinux/6.1/x86_64/updates/fastbugs/sed-4.2.1-7.el6.x86_64.rpm
After that installed, I was able to run yum -y update without any problems.
3
It could be an SELinux issue. Check /var/log/audit/audit.log for any related messages. See this informative post for more information, including a possible fix:
# chcon -t home_root_t /homedir/stefanl
3
You will need to apply the following (assuming that path is /www)
chcon -R -u system_u /www
chcon -R -t httpd_sys_content_t /www
And then make it survive a label:
semanage fcontext -a -s system_u -t httpd_sys_content_t /www
What I find it is easier to use another directory as a template when apply SELinux context to a directory:
drwxr-xr-x. root root ...
3
In order to establish an NFS mount, you need to have the portmap service running before attempting the mount.
Run /sbin/service portmap start and retry your NFS mount.
For RHEL6 and newer, this is in rpcbind - /sbin/service rpcbind start
3
Boot your machine as you would normally and when prompted to, Press any key to enter the menu do so.
In the grub menu select the entry you want to boot then press e
Highlight the kernel line and press e
Navigate to the end of the line and remove rhgb quiet then press enter
Press b to boot your system.
You should now see the system messages as it boots. ...
3
You need to tell the installer to do a kickstart installation. You can do this in one of two ways:
A. When you see the installer screen type linux ks=/ks.cfg
B. Since you are rolling your own media, you can change the linux label in the file named isolinux.cfg in the isolinux folder of the media to read:
label linux
menu label ^Install or upgrade an ...
3
I've managed to find an answer by myself.
#cat /etc/sysconfig/network-scripts/route-eth0
1.0.0.0/24 dev eth0
default via 1.0.0.1 dev eth0
It looks a bit better than lines in rc.local
At least it is related to routing in terms if RHEL way of network configuraion
3
The two attributes can be summarised as follows
Version - This is the upstream version, in your Java example, JDK 1.7.0.7 from Oracle
Release - This is the RPM package maintainers version of the rpm package itself, in the JDK 1.7 example this is "1jpp.5.el6_3". Let's say the package maintainers fix a bug in the RPM packaging (e.g. forgotten documentation) ...
3
OK, time for something even more drastic!
echo 1 >/proc/sys/kernel/panic
This instructs the kernel that when you kernel panic, to reboot the host in 1 second.
echo c >/proc/sysrq-trigger
This forces the kernel to panic. So hopefully you'll end up rebooting the host.
3
Assuming you are using hardware RAID, RHEL itself only sees the logical drive presented by the RAID. It is unaware of the underlying physical disks.
If it is a Dell server you can use OpenManage to run a script for an alert that will write to your console with wall or email you.
...
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