How much of a performance does using QEMU virtualization incur on a Windows host, when both the host and vm are running the same CPU?
Older articles indicate that using kqemu avoided the slow down in performance if both host and vm used the same instruction set. But it seems that kqemu is not used much recently or is not available for 64 bit systems.
Are more recent versions capable of maintaining performance without the use of `kqemu'?
Are disk partition labels or UUIDS stored in the partition area itself or in some other area of the hard disk?
e.g If the dd command is used is used to copy the raw partition image from one partition to another, or even onto a different hard disk. or the tar command is used (if it is stored in some special file) will the new partition have the same UUID or label?
Are they stored in some special area of the original physical disk or in the partition itself?
My PostgreSQL service must start after OpenVPN, and when I check the order rc.X directories they are listed as S16openvpn and S19postgresql, so they are in the right order.
However connecting to a database via the VPN fails and the logs always indicate that PostgreSQL could not bind at startup. My guess is that it takes some time for all the OpenVPN services to start and PostgreSQL is started before the loading of the OpenVPN networks is complete.
Is there a way for the PostgreSQL to try to reload and attempt to bind to the OpenVPN network before before giving up?
I have an archive I need to transfer to a remote destination but the target drive is not big enough to hold both the compressed archive and the uncompressed files.
I wonder if there are some utilities which can decompress the archive as the data arrives, rather than having to receive the whole thing then decompress it.
netcat is what seems to show up in my searches but I am open to any alternatives.
Is there a way to for the tar command to check for new files that are not already in the archive, or those that have been deleted (for good measure)?
What is the correct places to put bash aliases which should be available for everyone?
I want to set it up in such are a way that if some aliases are not available for somebody, it is because they overrode it themselves in their own settings.
I have created directory a created has these permissions - the other user has
drwxr--r-- 5 user user 4096 2012-09-15 19:30 sites
When do an ls -l on the directory as another user
ls -l /home/user/sites
this is the directory output. I thought without the x bit set on that directory the filenames wouldn't show at all.
d????????? ? ? ? ? ? dev.user.com
-????????? ? ? ? ? ? user.20120914_082804.sql.gz
d????????? ? ? ? ? ? shared
-????????? ? ? ? ? ? shared.tar.gz
-????????? ? ? ? ? ? www.20120914_083256.tar.gz
d????????? ? ? ? ? ? www.user.com
Is there some inconsistency here?
I use a variant of the simple script below from the Community Ubuntu Documentation described
tar -cvpzf backup.tar.gz --exclude=/backup.tar.gz --exclude=/proc --exclude=/lost+found --exclude=/sys --exclude=/mnt --exclude=/media --exclude=/dev /
I used it again on Ubuntu 12.04 and I saw some files from the /run being skipped by the script. Should the /run directory be added to the excluded directories?
Is it possible to set up OpenVPN on the client so that the gateway is used only on chosen destinations?
I have read this answer OpenVPN make redirect-gateway optional on making the use of the gateway optional, via push-reset.
If any client is configured to route certain destinations through the VPN, by using say FoxyProxy or changing the routing tables will the forwarding work as normal?
The OpenVPN documentation sets up a single certificate from a single CA to be used for all clients.
Is there a way to set the server to enable multiple certificates from different CAs so long as the clients have valid certificates from trusted authorities?
I need to run SSH commands remotely with the output displaying locally. But if the connection breaks I want the command to still run.
I am not talking so much about logging in and executing but doing ssh user@remotehost 'commands && command etc'
How can I ensure the command runs even if the connection breaks?
Is it possible to restore the functionality of /var/lib/apt/lists and /var/apt/cache after deleting them or minmizing them in some wa
I am trying to shrink down an Ubuntu VM to the smallest size and decided to delete /var/lib/apt/lists and /var/cache/apt with the intention of restoring them when the system needs to be updated. I have done /var/cache/apt without major side effects, simply recreating some directories reenables it. The /var/lib/apt/lists is the one I am unsure of. Is it possible delete it and restore its functionality by recreating like /var/cache/apt?
Does doing that destroy the knowledge apt and dpkg have of the systems configuration or is that stored elsewhere?
A lot of the tutorials on stunnel show only single forwardings. It stunnel limited to only fowarding and listening to one port on both ends, or can it handle both local and remote forwarding in the way putty, my favorite does?
Eg in putty or ssh you can do something like ssh -L xxxx:localhost:yyyyy -L aaa:localhost:bbbbb -R yyyyy:somehost:zzzz [email protected]. Does stunnel do the same over a single connection, or is it limited by SSL from doing so, who requires another separate connection?
I have transferred the disk of a a Hardyvirtual machine to another virtual machine with a different kernel but there is no equivalent of /lib/modules// on disk. How can the /lib/modules of the new kernel be added to the image to let it boot without error messages?
Is there apt-get command to download the kernel modules of the new kernel from the repository?
Does SELinux make Redhat more secure?
I can't remember the number of times when I have disabled SELinux because it kept frustrating my ability to get stuff running. Lots of times to there was no obvious reason why stuff wasn't working and I had to Google to discover why.
Given that most casual users will disable or weaken security when it appears to get in the way, with the exclusion of serious, enterprisey Redhat users, is SELinux really useful?
PS. Is there some tool that helps you log, track and manage SELinux issues across all applications?
How long does it take for an iptables rule to apply?
I use a script with the code below in an attempt to block hosts, but they don't appear to take immediately. Is there some delay, is iptables not working or is the code just plain wrong?
#!/bin/sh
echo $1 >> /etc/dropped_hosts
iptables -A INPUT -s $1 -j DROP
iptables -A OUTPUT -d $1 -j DROP
I installed nginx on Ubuntu Hardy and immediately realized that the PHP scripts were getting empty request arrays, ie whether GET or POST nothing was coming through, even the $_REQUEST array was empty.
When I switch back to Apache it was all fine.
The installation nginx version is 0.6.35-0ubuntu1.1~hardy1 and PHP is PHP Version 5.2.4-2ubuntu5.10.
What could be wrong?
How can an SSH command be setup to allow port forwarding but not execute commands.
I know that the ssh login can use -N to stop commands executing, but can the ssh config file be setup to disallow it?
Restricting the type of shell and the path in Linux is on option, but can it be done in the SSH configuration itself?
When I need to locate the IPs of devices by their mac address on a Windows system, I normally use Advanced IP Scanner (from radmin.com) to scan the network, then I use arp -a to list the mac addresses.
Is it possible to use nmap to perform the same function in Linux and possibly in Windows? Can nmap to the scanning and produce both IPs and MAC addresses?
I have tried arp -a in Linux but it doesn't seem to work as quickly as in Windows or appears to require some use input.
/vfclists
I have been getting problems disabling Checksum Offload in a lot of LAN adapters manually. Does setting the DisableTaskOffload value in the registry disable all of the related parameters regardless of LAN card? ie [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
ie is the use of the LAN adapter offload capabilities controlled by Windows itself?