Re: [CentOS] Live CD problems
Instead of unmounting the partition try using 'mount -o rw,remount ', I dont use the live CD much, but unless you screwup the rw, remount, or the path to the mounted partition it should either remount the partition properly or error that you didnt point to the correct path. I have rarely had issues with remount so it sounds like it would get around your issue. -- Trevor Benson dCAP, LPIC-1, CLA, Network+, MCP, CNA A1 Networks - Network Engineer DID (707)703-1041 FAX (707)703-1983 On Jun 30, 2010, at 4:43 PM, drew einhorn wrote: Hi, I'm trying to repair a remote system using the Live CD. I have VPN access to the subnet where it lives. An onsite person is booting from cd, and running a small script I provided to tweak the default firewall rule set to allow incoming ssh, and set a password for the centos user and start sshd so far so good I can remotely access the system. the problem is the live cd environment is very fragile. I need to rebuild the contents of a couple filesystems, so I need to umount them and remount them rw. If I make a mistake in a mount command instead of giving an error message and letting me try again. The system freezes and any other ssh session freezes, ahnd will not accept any more incoming ssh connections. the only way I have found to recover is have the onsite person reboot from cd and rerun the script allowing incoming ssh again. Hmm. I should try to talk the onsite person through trying something else from the console. Argghhh!!! This is more than just an annoyance. -- Drew Einhorn You can see a lot by just looking. -- Yogi Berra ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Anyone got Diskless BOOT working under CentOS ???
On Jan 5, 2009, at 11:02 PM, clem...@dwf.com wrote: Im trying to get a diskless boot set up under CentOS 5.2, and having no luck at all. I am to the point of running system-config-netboot, and whatever information I put in, I get an error message. Responding to the 2nd button on the first popup, which asks for NFS info, I put in the IP address of the current machine (the machine that will hold the boot images for the diskless machine) and the root directory for the diskless machine, viz /diskless/i386/CentOS5.2/root Which has a copy of my root file system, and in particular has a /boot subdirectory. When hitting FORWARD, I get the error message: The diskless subdirectory must be NFS exported and contain a boot subdirectory. Now Ive checked, vsftpd is running, nfs is running, and the above directory (and others) are in the /etc/exports file. I did this several years ago under Fedora, and dont remember having problems like this. Has ANYONE done this recently, and do you remember what you had to do??? I would REALLY like to exchange some e-mail with you. It would be nice if there was an example somewhere. -- Reg.Clemens r...@dwf.com ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos I remember getting something similar when the file and directory permissions were not set properly (and/or export permissions). So even when the boot directory exists, correct permissions to view or use it were not set properly. I didnt track down any information regarding the exact settings required for diskless boot, however when I copied the nfs export to a new export and chmod to world readable, then i got past the gui errors. I stepped back, adjusted the boot and then got the diskless client booting, however there were a few other things regarding permissions, home directories, and whatnot that also caused failure to boot, or get x started. Ill check out the wiki and see if anyone posted the information for file permissions, would be nice to get this going again.' Trevor ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] monitor invidiual client (PC) network traffic to server?
On Jan 6, 2009, at 6:31 AM, mcclnx mcc wrote: We have DELL servers with CENTOS 3 and 4 installed. Application is client/server type. Does there has way monitor invidual client (PC) network traffic to server? I would suggest either A) Run tcpdump from the server with a filter to only examine the packets from or to the client. The server is already receiving these packets, so now its just logging them. Take a bit of disk I/O, but usually not a big deal unless this is a database server or file server and it slows down file access. Still usually moot unless DB or I/O intensive server. B) Connect a laptop or workstation to a mirror port on your network switch, or whatever your vendor wants to call their 'bridged', 'administrative' port that receives traffic for all ports. If you have a hub ignore the port 'type' and just plugin. Now run tcpdump again filtering everything but packets from that IP or MAC. Afterwords you can take the file it creates and open it with wireshark to help you dig through it and figure out what was being sent back and forth. Trevor Benson A1 Networks ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] [OT] VPN/DMZ best practices
There is such a wealth of knowledge and personal experience on this list that I'd like to get your opinions on our current situation. Currently, we have a simple tri-homed firewall with the internal network snip 1. What are your recommendations for where the vpn (openvpn on linux) appliance should reside? In the dmz? Internally and configure the firewall to allow (and nat) vpn connections? On the unused interface in a different dmz than our hosting software? Somewhere else? For basics regarding your environment if Linux is your firewall gateway appliance and you have multiple internal networks behind it, then openvpn on the gateway is the simplest most effective way to connect the networks. Ssl vpn's can be behind network gateway devices, but then depending on the type of connection between sites (site to site or road warrior) you may need to configure additional routes on the gateway or each machine to return traffic. If its on the gateway for your networks then that box decides how to route it out properly. 2. Should I abandon the single firewall approach and instead use two firewalls in a more traditional setup (gateway firewall - dmz - internal firewall)? If so, where should the vpn appliance go? We do VPN's, Firewalls, and security for quite a few collocations and companies. Rarely is a company so security conscious that they want multiple layers of firewalls, and the complexity that can bring to the environment. Usually those that do have the staff on hand to troubleshoot complex networks as they need to adjust things. Not to say that this isn't done, many people do, but does your environment necessitate this level of security? If not lets stick to the single device approach. I'll probably have more questions based on your answers and I look forward to the responses. Thanks. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] What is vibr0 Network interface and what is it used for
My first guess would be a Virtual Bridge 0 interface. Did you decide to install Xen during the 5.2 installation? If so then it would automatically start up its network bridge to connect your Xen Guests to your local network (if you mapped the Xen Guest interface to work on this bridge). Trevor -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ivan Varbanov Sent: Thursday, August 14, 2008 12:06 AM To: CentOS mailing list Subject: Re: [CentOS] What is vibr0 Network interface and what is it used for It comes from virtual bridge (if you use vm,xen ...). On Wed, Aug 13, 2008 at 7:54 AM, Lunix1618 [EMAIL PROTECTED]wrote: Hello, I have see that my machine have an interface that named virbr0. I have no idea what is it and what it using for ? I am not configured any IP address for it but I see it had an IP address and see it listed in firewall config. Can anyone give me an explanation about this or point me to a document that describe it ? My machine running CentOS 5.2 and do not have internet connection from the installation time. Thanks, virbr0Link encap:Ethernet HWaddr 00:00:00:00:00:00 inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0 inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:35 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:9143 (8.9 KiB) ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos __ Information from ESET NOD32 Antivirus, version of virus signature database 2806 (20080118) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] What is vibr0 Network interface and what is it used for
Sorry missed the answer you provided the first time. T ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] Announcing the CentOS on Laptops initiative
Sadly, for now, you have to request access to be allowed to create or edit these pages. I hope in the future we will have a more liberal view wrt. the wiki. PS I created this structure for your X60 for now, I plan to add my own laptops soon (but it does not include a X60). If you can add your information to this existing page, I am sure this is very valuable for another X60 owner. Can I get a Thinkpad R51 page setup if not already and access. About to blow out the FC6 and load CentOS 5 since I have to finagle the wifi every so often. Figured document as I go lest I forget. Trevor ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
