I found this in the large and growing list of downloadable vmware appliances: http://www.vmware.com/vmtn/appliances/directory/316. I haven't run it yet, but it claims to provide a way to mirror running windows boxes over iscsi to vmware disk images, then allows you to boot that image under vmware as a replacement for the server with little downtime.
Has anyone attempted something like this with Centos - or know if software mirrors work over iscsi?
Has anyone attempted something like this with Centos - or know if software mirrors work over iscsi?
I haven't. I'm experimenting with a few technologies for high availability:
http://www.drbd.org/ http://www.howtoforge.com/high_availability_loadbalanced_apache_cluster
I'm leaning towards the later...
-Ben
-- Les Mikesell lesmikesell@gmail.com
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
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On Thu, Jun 29, 2006 at 02:53:45PM -0500, Les Mikesell wrote:
I found this in the large and growing list of downloadable vmware appliances: http://www.vmware.com/vmtn/appliances/directory/316. I haven't run it yet, but it claims to provide a way to mirror running windows boxes over iscsi to vmware disk images, then allows you to boot that image under vmware as a replacement for the server with little downtime.
This really shouldn't be hard to do with linux. it's a lot harder with windows since windows cares so much about the specifics of the hardware it is running on. The only things you need to change should be the initrd. You should be able to build an initrd that has all the required drivers for both your physical hardware and vmware.
I have more or less done this with a running debian unstable system.
Has anyone attempted something like this with Centos - or know if software mirrors work over iscsi?
I haven't, but I'd be real surprised if it didn't work.
danno -- dan pritts - systems administrator - internet2 734/352-4953 office 734/834-7224 mobile
On Fri, 2006-07-14 at 02:20, Dan Pritts wrote:
On Thu, Jun 29, 2006 at 02:53:45PM -0500, Les Mikesell wrote:
I found this in the large and growing list of downloadable vmware appliances: http://www.vmware.com/vmtn/appliances/directory/316. I haven't run it yet, but it claims to provide a way to mirror running windows boxes over iscsi to vmware disk images, then allows you to boot that image under vmware as a replacement for the server with little downtime.
This really shouldn't be hard to do with linux. it's a lot harder with windows since windows cares so much about the specifics of the hardware it is running on.
The procedure you use with windows is to install the disk driver it will need under vmware before the copy. Everything else will auto-detect. Then once it is up you install the vmware tools which provides better drivers for the video and network.
The only things you need to change should be the initrd. You should be able to build an initrd that has all the required drivers for both your physical hardware and vmware.
I have more or less done this with a running debian unstable system.
Has anyone attempted something like this with Centos - or know if software mirrors work over iscsi?
I haven't, but I'd be real surprised if it didn't work.
The piece that I haven't been able to match is Windows (server versions) ability to convert a standard NTFS disk to dynamic, then add a mirror on the fly. If you didn't install on RAID1 to begin with and remove one of the partitions, how do you get a working system to the point where you can add a mirror? You'd probably have a fair chance of making things work with an rsync copy while running, followed by an rsync in single user mode with databases, etc. shut down, but what I really want is a live mirror that would always be up to date any time the physical server died.
The SME Sever distribution will install itself on RAID1 partitions with missing mirrors, but they had to modify the stock Centos installer to do that.
On Fri, Jul 14, 2006 at 07:53:21AM -0500, Les Mikesell wrote:
The procedure you use with windows is to install the disk driver it will need under vmware before the copy. Everything else will auto-detect.
good to know, thanks.
The piece that I haven't been able to match is Windows (server versions) ability to convert a standard NTFS disk to dynamic, then add a mirror on the fly. If you didn't install on RAID1 to begin with and remove one of the partitions, how do you get a working system to the point where you can add a mirror? You'd probably have a fair chance of making things work with an rsync copy while running, followed by an rsync in single user mode with databases, etc. shut down, but what I really want is a live mirror that would always be up to date any time the physical server died.
Ah, i see. I have read (but not actually tried) that you can convert a filesystem on a raw device to a raid1 but I can't remember the details. There were issues with needing extra space at the end of the physical partition. I imagine if you partitioned your disk with an extra cylinder after each partition it would work.
danno -- dan pritts - systems administrator - internet2 734/352-4953 office 734/834-7224 mobile
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Benjamin Smith -
Dan Pritts -
Les Mikesell