When there is a problem with access to yum repos (for example if a needed proxy isn't configured), running a command like 'yum update' will wait for a very long time trying lots of different mirrors. Sometimes that is good, but sometimes I would rather check quickly whether access to yum repos is OK.
Is there a way to get yum to quickly check its connectivity and give me a status code indicating whether access to remote repos is OK?
My application requires per-directory verification of SSL client certificates (i.e. when user requests /foo we require they have a client certificate and verify it, but when they request /bar we don't care if they have a client cerficiate). Apache has nice support for this, as the SSLVerifyClient setting can be applied on a per-directory basis, and apache will do SSL renegotiation in this instance to require the certs when needed, but not prompt for a certificate when accessing other directories.
My question is: which other web servers have this capability? Using apache to fulfil the SSL handling requirement is OK, but it is not my only requirement and I would like to know what the other options are.
Someone just asked me 'how long should we keep logs for our application', and my answer was 'until the disk is full' as there's no reason to throw them away other than running out of space.
However, standard logrotate wants us to specify a specific period + number of rotations. Is there something similar that would let us say "rotate daily, and keep as much history as you like until there is only 5% space free"?
The platform is Redhat Linux.
The output from 'mysqladmin processlist' looks like this:
+-------+------+-----------+-------+---------+------+-------------------+------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+-------+------+-----------+-------+---------+------+-------------------+------------------------+
| 4411 | root | localhost | mydb1 | Sleep | 86 | | |
| 12911 | root | localhost | mydb1 | Sleep | 50 | | |
| 65142 | root | localhost | mydb1 | Query | 4 | copy to tmp table | OPTIMIZE TABLE my_tble |
| 65428 | root | localhost | | Query | 0 | | show processlist |
+-------+------+-----------+-------+---------+------+-------------------+------------------------+
From an 'Id' value in that table, how can I trace back to the PID of the process which created the connection, to figure out who is doing what? All the connections are via a local socket.
I have some virtual machines which were clones of the same original disk image, which contained some LVM volumes. When I clone these, I end up with multiple LVM volumes (albeit on different hosts) which have the same 'unique' ID. Is there any way I can get LVM to change the UUID of an existing volume?
I have some SAS devices in a server, I would like to find out what their SAS addresses are. How can I do that in Linux? I'm using CentOS 6.
I would like some of my domains to start automatically when my host starts (I'm using libvirt+KVM on ubuntu). I guess I could put some "virsh start..." statements in rc.local, but is there a way to configure this within libvirt/virsh?
Chef/puppet are great tools for managing the configuration of individual hosts, but they seem to fall down slightly when a configuration has dependencies between hosts. For example, I'd like to have a web server configuration that tries to start an application, but only if the database has already been started (on another host). Is there some similar tool that allows configurations to be specified which span hosts, or are there some extra bits of chef or puppet that make this possible?
What's the best way to tell from a shell script if the host has restarted since the last time the script was run? I can think of storing the uptime in a file on each run, and checking if it has decreased, but that doesn't seem completely robust (a server might restart start quickly, store a low uptime, then reboot slowly and come up with a higher uptime).
Is there something like a "started at" value which would be guaranteed to change only on a reboot? Or some other good way of detecting a restart?
Is there any way to set up a virtual infiniband network within kvm/qemu? If not, is there a viable open source alternative which would allow virtual infiniband networking?
(Note that I'm not looking to give VMs access to a physical IB network, I'm looking to have an entirely virtual IB network with no IB hardware)
I have some iSCSI targets mounted on a linux host as /dev/sd*. How can I query the iSCSI ID from the device node?
This is on CentOS 5, using the iscsi-initiator-utils package.
Here's a strange thing I haven't seen before -- a directory whose size is reported by ls as 0 instead of 4096, and I can't create any files within it.
# ls -ld lib home
drwxr-xr-x. 2 root root 0 Feb 7 03:10 home <-- it has zero size
dr-xr-xr-x. 11 root root 4096 Feb 4 09:28 lib
# touch home/foo
touch: cannot touch `home/foo': No such file or directory <-- and I can't create files in it
# rm home
rm: cannot remove `home': Is a directory <-- look, it really is a dir
So what does it mean for a directory to have size 0 instead of 4096?
Filesystem is ext4 on fedora core 14.
The output of mount is:
/dev/mapper/vg_dev-lv_root on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/vda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
Output of du -s /home:
0 /home
Output of stat /home:
File: `/home'
Size: 0 Blocks: 0 IO Block: 1024 directory
Device: 15h/21d Inode: 34913 Links: 2
Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2011-02-07 03:45:46.188995765 -0800
Modify: 2011-02-07 03:11:59.980995019 -0800
Change: 2011-02-06 07:58:45.874995002 -0800
Apparently OpenVAS originated as a fork of Nessus. It is very easy to install and use OpenVAS because it's, well, open. However, am I kidding myself if I just use that instead of Nessus? Should I be using both, or if I use Nessus then is OpenVAS surplus to requirements?
To break it down into non-subjective sub-questions: * Is openvas a superset or subset of nessus? * Is one updated more often than the other? * Does one have a bigger vulnerability database than the other? * ...or are there other qualitative differences that I may be missing?
I have an apache configuration file which works fine when it's placed directly in /etc/httpd/conf.d/foo.conf. However, when I move the same file somewhere else (for example, move it to /tmp/foo.conf) and then create a symlink with ln -s /tmp/foo.conf /etc/httpd/conf.d then apache fails on startup with:
httpd: could not open document config file /etc/httpd/conf.d/foo.conf
I've tried making the file and the symlink mode 777, and tried changing them to be owned by the apache user.
It seems like apache is failing to load the file purely on the basis of it being a symlink, but I'm sure I've used symlinks successfully on other machines. Is there something I'm missing? Does apache have an option for refusing to load config files if they're symlinks?
The operating system is CentOS 4.4, apache version 2.0.52.
In windows batch scripts, how can I iterate over all drive letters which correspond to physical volumes or mapped shares?
The windows XP sigverif tool is useful for identifying non-signed executables, but does not seem to be amenable to scripting -- is there a command line equivalent?
I have a server which is accessed by IP address over a LAN. The IP address is sometimes changed, and it is never accessed with a DNS hostname. Is it possible to get a CA-signed certificate which doesn't depend on the host having a particular DNS hostname?
I am aware that I could use a self signed certificate, but I'm not in a position to install my own cert on client browsers, so it would result in the horrible self-signed-cert warnings whenever a new user accesses it.
I'm using Apache on Linux in case it matters.
What command can I use to strip color-code escape sequences from a text file? Ideally something I can pipe through. If I have a file with a bunch of coloured text rainbow.txt, what goes in the gap:
cat rainbox.txt | *something* > plain.txt
I'm working in bash on CentOS 4.4.
While uninstalling an RPM on CentOS 4.4, I see
error: %preun(mypackage-1.0) scriptlet failed, exit status 1
How can I find out exactly what it's trying to run, so that I can poke around in the script and find out why it's failing?
Possible Duplicate:
Can you help me with my software licensing question?
If I have a development environment running in (for example) three VMWare virtual machines, each one containing a Windows installation, then I need three Windows licenses.
In either case, I presume that I'm only running three virtual machines at any one time, there are just many copies of the files representing the virtual machines at various points in time.