CentOS 5 :: Configure An ISCSI / DRBD High-availability Cluster
Jul 23, 2010
I'm trying to configure an ISCSI/DRBD high-availability cluster and I'd like to know what is the best option between OpenAIS and Heartbeat. I've seen they both are included in Centos Repos, yet OpenAIS requires installing 2 addition repos to install Pacemaker (EPEL and Clusterlab repos).
Is there a way to create a high availability environment between two CentOS machines? I don't mean just the HTTP service or just one other thing. I need the entire server synced in real time ready to take over if the next goes down.
i have a two node drbd cluster, while drbd1 is primary and drbd2 is slave i should make drbd1 slave and unmount drbd partition and make make drbd2 primary and mount drbd partition to see content on drbd2is it any way to automate it so as drbd1 goes down, drbd1 make itself primary and mount the partition?
I have 2 web servers running apache hosted at 2 data centres on 2 different IP ranges.The 2 servers are an exact clone of each other hosting www.example.com.What I am trying to achieve automatic failover. Say my first data centre gets wiped out, how would customers reach my website on my second server in the second data centre by still typing www.example.com?The aim is for the customer not to notice any difference.
Now that I have setup a proxy server, as a next step I want to run it in fail-over high availability mode, so that if one proxy is down due to any reason, second proxy should automatically be up and start serving requests.
i am using the redhat cluster suite (luci and ricci) on my centos 5.3. i have 2 nodes in a cluster. when i poweroff the first node on wich a vm service is running, the service switchtes to node2. so far, so good :) but when i restart node1 the service is not failback to node1! i have created a failover domain with both nodes and priorized whre node1 has prio1 and node2 has prio2.
I am trying to build GFS2 cluster with 2 or 3 Fedora 14 nodes, but I've encountered some problems from the start. First luci does not work at all in Fedora 14. There is no luci_admin and even if I manage to start luci service, I get a blank white screen when I try to open it from the browser. I've googled a bit and found that I'd might be able to setup GFS if I manage to build cluster.conf manually and start the cluster suite, but I cannot find documentation on how to create cluster.conf anywhere. If anyone knows how to setup GFS2 without a cluster suite or how to configure cluster.conf.
I'm trying to build a Fedora 12 cluster to run DHCP on top of two servers using pacemaker and drbd. The pacemaker runs great but i'm having the hardest time getting DRBD installed.
My kernel version is 126.96.36.199-99.fc12.i686.PAE First i tried to [root@dhcp-primary drbd]#yum install drbd this doesn't give me everything because apparently the kernel module for DRBD must be built from source. so i unpacked drbd-8.3.6.tar.gz and tried :
I'm not very experienced in compiling from source i'd love to make an rpm for this but after scouring the web and trying different install methods, I am still at a loss.
I am trying to setup a High-Availability HTTP Load Balancer With HAProxy & Heartbeat using the below links.
I have all RHEL 5.4 servers hosted on VMWare.
This is the scenario, as given in the links as wells as my setup.
Load Balancer 1
Load Balancer 2
Web Server 1
Web Server 2
I have followed all the steps mentioned in the links religiously except the 2.2 here, in which it is asking to configure the vhosts. I could not really understand , what is to be placed in /etc/httpd/conf.d/vhosts.conf file and in which Web Server.
Due to this step only, I think I am failing in Failover test given in Point 4.1 here. I am able to open the webpage by [url] which gives the content of Web Server 1 (http1.example.com). But, when I try to shutdown the http service (to check failover), it does not shows the contents of Web Server 2 (http2.example.com)
Although, I am able to succeed in Failover Test 4.2, in which shared IP 192.168.0.120 switches when I try to start/stop the any of the Load Balancers.
I am kinda stuck while providing solution for the above problem. I have achieved the fail over using keepalived but not sure how can we replicate the data from one server to other seamlessly and have them in sync with each other. My prime requirement for this project is end user should not notice the fail over and replicated copy of data should be available on the secondary as well.
I'm running RHEL 5.5 on two workstation for test DRBD and I get something that sound strange ...[URL] Quote:Protocol C. Synchronous replication protocol. Local write operations on the primary node are considered completed only after both the local and the remote disk write have been confirmed. As a result, loss of a single node is guaranteed not to lead to any data loss. Data loss is, of course, inevitable even with this replication protocol if both nodes (or their storage subsystems) are irreversibly destroyed at the same time. By far, the most commonly used replication protocol in DRBD setups is protocol C.
I've been working at creating a highly available set of host servers for a linux diskless boot cluster.Each host machine is fitted with redundant power supplies and two 1TB drives in a Raid-1 configuration.When I first started this project they each had twin 160GB drives. In my original setup I had both nodes acting as primary systems so that I could mount /dev/drbd0 to my /data directory and see changes immediately.It had worked in the past where I could make a file in /data on the first machine and it would show up in the /data directory on the second machine. One day this had stopped working where if I made a file on the first machine it would display on the second one until I unmounted /data and remounted it to the /dev/drbd0 disk.
This is when I bought the new disks and decided to start from scratch. The weird thing is that if I make a file on the primary and remount on the secondary to see it and then delete it from the secondary and THEN delete it on the primary, the primary throws no error however it goes into read-only mode because it knows that file was already gone.Below is my configuration file, sda8 is an 820GB partition which is used for all of the data I want to replicate, currently populated with ~10GB of data. Sda7 is my metadisk partition which is 500MB large clearly more than needed by drbd.Also you will notice "incon-degr-cmd "halt -f";" is commented out. This is because when I go to actually use it drbd throws an error when reloading the configuration and I'm not sure why that is either
i have problems with my failover machines and cant locate the cause. The last update is quite some time ago.So will it hurt my configuration when I do an yum-update? I have 5 Xen VM on each machine, also they replicate with drbd and heartbeat. Can I just update the dom0 and leave the VM untouched inside?
The first server I installed installed fine. The second server, installed with the same config, went to "kernel panic not syncing no init found try passing init= option in kernel" error. I tried reinstalling but it keeps going to that error after install reboot. The storage is ISCSI connected via Intel Server Adapter, which allows it to boot from ISCSI. Not sure if that's the cause for the problem, but the first server is connected to the same ISCSI and installed just fine.
Is there a way that I can make sure ISCSI module installs during installation? Although I think it is installed since it's able to copy the files and setup /dev/sda. I just wana make sure that it installs during setup.
I have never done this before but stood up a new Debian (testing) x64 system. It only has 146GB available for RAID1 so I created a 500GB iSCSI LUN on my NAS device on the network and am really confused how I can attach my Debian to the iSCSI LUN I created. Right now the OS is installed all locally on the machine but I would like the iSCSI LUN to be the /home directory for mail storage. Is this possible or do I need to mount the LUN to a newly created folder / mount point that is locally attached?
I am trying to configure redhat cluster first time but no idea how to do it. I am using rhel 5.2. I have copied cluster rpms from redhat media and tried to install them but facing alot of dependencies problem. Can some one please guide how can i do redhat clustering from start. I am doing this for configuring single node clustering for zimbra suite but it is the requirement to configure redhat cluster first. One more thing i am using two virtual machines installed by using virtual box.
I am planning to configure RedHat cluster on vmware, i dont know how to configure, i googled a lot but couldn't find satisfactory docs for configuring, can any one provide me step-by-step or good docs to go ahead.
I want to configure two node cluster for qmail-toaster?? My idea is.. if one server hardware gets failed it should transfer/migrate service to other qmail-toaster server with all settings like ... domains/users/password etc etc.
Decided to experiment with iSCSI targets in 5.1, looks like a new addition. got everything setup with these steps with one caveat, on reboot the exported targets are gone, so the simple questionis where do the tgtadm commands need to be to export the targets at system startup? apparently tgtadm does not save anyting anywhere. >set up the target box yum install scsi-target-utils chkconfig tgtd on service tgtd start
look for your newly added iSCSI device in /dev or tail the syslog to see what the device name is. Partition, format, mount it up and have fun. But don�t reboot or you will have to export the targets again :(
I seem to get logged into the NetApp filer fine - it shows the session, but I don't get a device. And don't panic - the system is CentOS 5.4, but the system is named OpenVMS (don't ask . . . ) iscsiadm shows me logged into the NetApp and the session is up.
I am trying to setup Rocks Cluster on a Cluster containing 1 Master node and 23 slave nodes connected via a Switch. The master node's eth1 is connected to public IP and eth0 is connected to the slave nodes via the switch.
I was able to install the Rocks cluster on the machine, I configured the IP for master through DHCP. When I run the command 'insert-ethers' on the master node, it doesnot get me any slave nodes.
I've been trying to figure out how to set up a partition on my CentOS serve r as an iscsi target, so I can access it from another CentOS client.I've been reading the manuals and various pages on the web, and nothing is very clear. I just want to be able to create a partition on my server, define it as a target, and then have my client initiator mount it.
I have an iSCSI device that is large, ~17TB usable, and I've created an XFS file system at the device level. I mount the device no problem and am able to touch and remove files without issue. I start my application and within about 5-10 minutes I start seeing the following entries appear in /var/log/messages
I built a CentOS 5 Linux cluster with GFS storage using local RAID volume and share it with gnbd_export/import on two web-servers. Now I need to expand that storage to another servers local volume. I saw the picture in the manual, but I don`t know, how can I create that scheme.
I can use gnbd_export on the second server and gnbd_import on the first. In that case I will have two volumes on the first storage and I can expand volume group, logical volume, etc on it.
I have a server wich is connected to an iSCSI storage and gets harddisks from this storage. Sometimes I have to add new disks to this server. Everytime I add a disk and make an /etc/init.d/iscsi restart on the server the disks don't have the same device name as before the iscsi restart.
It should be possible to gave the disks persistent names using udev rules. Now I tried to create different rules in "/etc/udev/rules.d/99-static-iscsi-names.rules" e.g.
# /dev/sdc KERNEL=="sd*", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -s %p",RESULT=="360a98000503355344c4a576864467877" NAME=="sdc%n" In "/etc/rc.local" I added "/sbin/start_udev" and in "/etc/scsi_id.config" I added the line "vendor="NETAPP",model="LUN",options=-g"
well sorry I'm new in this but I just made my cluster with about 4 good machines each with 2 or more gbs of memory and dual-core processor but the question is i can install an operating system in nodes as having the frontend or not different if possible, and how i can do it because i don't now how and i don't find material and tutorials that can help me..
I am trying to install iscsi-target on centos 5.4 i386. When I go into the iscsi-target directory and type make I get the following error: [root@cluster-storage iscsitarget-1.4.19]# make cc: /lib/modules/2.6.18-164.el5/build/include/linux/version.h: Datei oder Verzeichnis nicht gefunden cc: keine Eingabedateien /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -le: unary operator expected /bin/sh: line 0: [: -lt: unary operator expected make -C usr make: Entering directory `/opt/iscsitarget-1.4.19/usr' ..... make: *** [kernel] Fehler 2
We have a Centos 5.6 server mounting two iSCSI volumes from an HP P2000 storage array. Multipathd is also running, and this has been working well for the few months we have been using it. The two volumes presented to the server were created in LVM, and worked without problem.We had a requirement to reboot the server, and now the iSCSI volumes will no longer mount. From what I can tell, the iSCSI connection is working ok, as I can see the correct sessions, and if I run 'fdisk -l' I can see the iSCSI block devices, but the O/S isn't seeing the filesystems. Any LVM command does not show the volumes at all, and 'vgchange -a y' only lists the local boot volume, not the iSCSI volumes. My concern is that, the output of 'fdisk -l' says 'Disk /dev/xxx doesn't contain a valid partition table' for all the iSCSI devices. Research shows that performing the vgchange -a y command should automatically mount any VG's that aren't showing, but it doesn't work.
There's a lot of data on these iSCSI volumes, and I'm no LVM expert. I've read that some have had problems where LVM starts before iSCSI and things get a bit messed up, but I don't know if this is the case here (I can't tell), but if there's a way of switching this round that might help, I'm prepared to give it a go.There was absolutely no indication there were any problems with these volumes, so corruption is highly unlikely.
I'm having a very strange problem with red hat cluster. After testing it in the lab, I tried to install a new cluster and received the following error: cman not started: Cannot start, cluster name is too long or other CCS error /usr/sbin/cman_tool: aisexec daemon didn't start I've checked the internet for that error, but nothing. I decided to to take the example from cluster.conf man, which looks like that :
And still I get the same error. I can find my servers both from DNS (FQDN and short name) and they also appear in /etc/hosts.