hi linux expert, i just create account into this website.. i have expected some thing from you. my technical issue and details:- i have install red hat linux 5.6 Enterprise Edition into two vmware on single computer and now i want to connect and communicated two vmware each other, i have tried but i can only cross ping ip but not able to ping cross hostname... will you please help to solve out .
I apologize in advance for requesting help on this, but I have nowhere to turn.
My knowledge of Linux is limited and Linux guru's in South Africa are few and far between. My knowledge of Linux extends to setting up the product with a GUI and a few command lines from 20 years ago when I programmed in SCO linux V. Most of the unix is forgotten, but I know a few Linux commands.
If you have the time to give your opinion on this, I would sincerely appreciate it.
Here's the situation. As a hardware (and Windows network guy) supplier, I was told to set up a Linux box (to the customer specs) with CentOS 6 on a site. I was told to NOT use on-board controller RAID as the Linux guru we used claimed centOS gave him issues and to rather use the Linux RAID setup.
I allowed this guy (the guru) in another city to dial in and configure. No real guru's in our city. Main Board was a standard desktop board with Intel RAID controller, but Intel RAID was not used. I checked it at my office in the GUI and the software RAID was fine and the guru was supposed to check my work once it got to the site. I felt everything would go smoothly. I ran it at my office for two ~ three weeks testing it, playing with it. I had never used centOS 6 before.
File Server was then taken to site and the Linux guru prepped it, checked it, and then the software vendor set it up to run a factory's mission critical application and the server ran fine for one full day after this.
The day after going live, the original Linux guru sent me a mail saying one of the drives were dead and I was to go in and check. I asked if I need to do a backup, but was told it should not be necessary.
Sure enough, the GUI for centOS showed the raid degraded. Linux Guru asked me to shut down PC and check cables. I clipped on my wrist strap and shut down PC. Unplugged cables and re-seated both. PC started up fine.
By the way, when a raid fails in CentOS, does it take the drive off-line completely, de-activate it, and a restart will fix it? I ask because I read this on a site somewhere:
Some information about Linux software RAID - good points and bad
> When trying to read sectors from a disk and the disk fails the read:
> 1.) Read the data from the other disks in the RAID and
> 2.) Overwrite the sectors where the read error occur.
Note: this is NOT how current linux softraid code works, it's
how it *supposed* to work. And right now, linux raid code
kicks a drive out of the array after *any* error (read or
write), without trying to "understand" what happened.
Is it therefore the power went off, and the RAID broke, automatically took the drive off-line? And it wasn't a loose cable? It does not matter, of course if it was a cable or not, as the raid should have worked when I plugged it back in, right?
Anyway RAID still indicated it was degraded after switching on, but drive was visible now. (It wasn't before). He then did something on his end and said something was now wrong with the primary drive as he was getting errors on the console. He told me to go to the console and sure enough there were errors popping up. He became quite nervous (as did I) and said BOTH drives must be faulty. I went like: "What? How, the things been running for a full day. How's that possible? He was like... How do I know?"
After a reboot - a fatal error appeared "Kernel Panic - not synching: Attempted to kill init. Panic occurred. Switching back to text console" and the command prompt wouldn't come up and the Linux guru said we had lost all the data on the partition and it was garbled. The customer lost a day's work.
As I had another identical PC in my vehicle awaiting delivery, I grabbed that, set it up with CentOS and he started working on it remotely. A few days later, after the linux guru had finished preparations again, the software guy said errors were appearing /or e-mailed to him:
xxx is where the customer's server name was - I removed it.
Subject: Fail event on /dev/md0:xxxxx.xxxxxx.xxxx
This is an automatically generated mail message from mdadm running on
A Fail event had been detected on md device /dev/md0.
It could be related to component device /dev/sdb1.
Faithfully yours, etc.
P.S. The /proc/mdstat file currently contains the following:
md1 : active raid1 sdb2(F) sda2
30718908 blocks super 1.1 [2/1] [U_]
bitmap: 1/1 pages [4KB], 65536KB chunk
md3 : active raid1 sdb5 sda5
32766908 blocks super 1.1 [2/2] [UU]
md0 : active raid1 sdb1(F) sda1
225279864 blocks super 1.0 [2/1] [U_]
bitmap: 1/2 pages [4KB], 65536KB chunk
unused devices: <none>
I sell almost 400 PC's a year. I have an exceptionally low failure rate on hard disks. These were 2 x Seagate drives and an Intel Desktop mainboard (This is what was requested for "Server" by the software guys - ALL hardware was to their spec).
Now, here's the thing: these two PC's are probably the first that I have ever had complaints about this year. I am a Windows, hardware, network guy. After this second problem, I said to them "Screw it guys. I'm walking away. Get your own PC, work it out among yourselves. Tired of being middleman. I am done with Linux. I don't have these issues with Windows and RAID. I use hardware RAID. Can't be arsed for this."
NOW... here's the main thing I wish an answer too: The original "server" machine we used that allegedly had two faulty drives? I have been using on my desk with Windows 8 for the last few weeks. No RAID errors. No blue screens. No problems. As for the one I left on-site, I have not had an opportunity to reload the second machine /or run diagnostics to check that.
So, now I ask you: is it more possible that the drives were fine and the guy gave an instruction to mirror the drive the wrong way or is it possible that it was just a Linux glitch in RAID? I did ask the Linux guru to check my work as I installed it, but the PC ran fine right up to the point we plugged in the cable and he typed something to resynch the drives. There is honestly no fault with the drives and I have the drives and paperwork to back it up. I strongly suspect he made a mistake and is not being truthful.
I would sincerely like an informed opinion on this as the Linux guru and the programming guy says things like: "The drive may have crashed at that moment, the PC wasn't under a heavy load, therefore the problems with the drives wouldn't have been easily detected." - The Linux guru now want to charge for double-work and I honestly think it's a case of him screwing up and still profiting from it.
The Linux guru also defends himself by saying: "I showed you the errors on the console. That drive must be faulty" - and me being ignorant of Linux, could those "errors" not just have been the result of an old copy of the mirror garbling over the current, good copy or perhaps he started the mirror and realized - Oh my goodness, I'm mirroring the wrong way. I must stop this" and this resulted in the error.
What do you think is more likely taking into consideration that all the hardware is running fine. I have it as proof on my desk. I have reloaded Windows twice on it now. I have run diagnostics on the drives. No problems. No RAID errors.
I sincerely apologize, that I, as a stranger, bombard you with this situation and these questions, but I am feeling like someone is lying and need an honest opinion and all the Linux guys here are "over-confident" Guru's who's opinion's I am wary of.
If you can, I would appreciate your opinion. I am completely in the clear here as I acted on instruction, but I just feel that the customer who the Linux box belongs too isn't being handled fairly. Read More...
I am able to build a bundle using the mkbundle command, after that when i try to run the application in another linux system where mono is not installed.The application is not executed and no errors.
Anyone please help me Read More...
I am able to build a bundle using the mkbundle command, after that when i try to run the application in another linux system where mono is not installed.The application is not executed and no errors. Anyone please help me.
we are to develope a project on linux whose aim is to automatically encrypt files after logoff and to decrypt them using password after log in
this is to be made by chging source code of linux ...........
can any one help me on this???? Read More...
I have seen many posts and forum to setup the thin client environment and every thin client has at least a mini OS that boots up the hardware and then establishes the connection to the Server.
But, here my query is very different.
I have recently seen an environment, where the thin clients had NO HARD DISC / FLASH.
When the "diskless thin client" boots up, the PXE-Boot fetches an IP Address from DHCP Server and then boots Windows 7 Client OS over the network from the server.
The Linux based server was setup in such a way that it responded to the DHCP request for the PXE-boot phase and then transferred the Windows 7 Client over the network to the Diskless Think Clients.
I Searched and googled lot about how to setup such server and came across LTSP Server configuration on Ubuntu, but unfortunately, it never worked the way they showed on the forums or blogs.
Could someone help me understand how to setup the server environment ?? Read More...
OS used : CentOs 5.4
Kernel : 2.6.18-164.e15 on an X86_64
Error occurred: Could not start the X server (your graphical environment) due to some internal error.Please contact your system administrator or check your syslog to diagnose. In the meantime this display will be disabled. Please restart GDM when the problem is corrected.
Following steps taken to Solve but still same issue...
1)When proceeded further by pressing Enter, got the following error. Could not able to login.
CentOS release 5.4 (Final)
Kernel 2.6.18-164.e15 on an X86_64
(none) Login :
2) Unable to connect with any run levels except single user mode.
3)When connected to Single user mode during startup, got following errors during boot
Starting udev : cannot execute binary file
/etc/rc.d/rc.sysinit line 901 :/bin/rm : cannot execute binary file
sh: /bin/mount: cannot execute binary file
sh: /bin/hostname: cannot execute binary file
4)System doesn't read rc.sysinit file during boot stage and hence couldn’t able to resolve hostname and any other services that is present in rc.sysinit file.
5)When given startx from single user mode, got the following error
xauth error in locking authority file //.xauthority
Fatal server error
could not create lock file in /tmp/.tX0-lock
6)When given mount -o remount,rw / to make the system read-write from single user mode,
got the following error,
sh: /bin/mount: cannot execute binary file
7)On further assessment, made an attempt to check any possible disk block errors
behind root filesystem going read-only.
8)went into linux rescue nomount option from centos installation CD and tried fsck.In doing so, came to know disk block check was clean
9)But still the problem exists and the server is still down. Unable to go into either run level 3 or run level 5 to bring the server up Read More...