EVA6000 lun presentation to diferent OS servers

[otukile]

I have a creative customer who is giving me a headache. He wants a situation where he can have a lun than can be mounted by different OSs on the host. They will not access the lun at the same but at different times. For example, at Point A it will be mounted by Server X, and at Point B server X will unmount and the Lun will be mounted by Server Y. These servers are of different OS (eg Server X = Win2K, Server Y=Linux)


Questions:

1. Is it possible even when the servers are of the same OS?

2. IS it possible if the servers are different OSs?

[Steven Clementi]

1. Is it possible even when the servers are of the same OS? When the servers are the same OS, there should be no problem.

2. IS it possible if the servers are different OSs? In the case of Linux vs. Windows... as long as your linux box can read NTFS OR your Windows box can read EXT3 or what ever file system your going to use, there should not be too many problems.

Is it recommended and/or supported. I would think that it is neither.


Steven

[Ivan Ferreira]

There are some problems.

1- You must use a filesystem that is supported on both OS. The linux supports RW access only to vfat filesystem. I won't use vfat filesystem for a any producion environment ever.

2- The vdisk configuration specifies the host OS when is presented, you need to change this, but i have no idea how will affect the change.

What you clients wants, is a non recommended configuration. There should be another options to replicate/mirror the data so both can use the same data.

Conclutions:

1- Yes, is possible when the servers are of the same OS, if they won't access the same lun at the same time. If the O.S. is Windows, the disk should be basic, not dynamic (because of the signature).

2- No, is not possible when the servers are not the same OS.

[Steven Clementi]

I know that there is a linux project that allows your linux install to read NTFS, but not write.

Do you need to RW? or just read?


The OS designation is located on the Host Definition on the EVA6000, not the Vdisk config. This is to tell the EVA certain parameters that it needs for the host to access a vdisk properly. Not sure if this effects the vdisk in any way, but it might.

Take a look here http://linux-ntfs.sourceforge.net/ for the ntfs readonly info. I would assume you would need more than just linux support since you only used w2k/linux as an example, but at least this is a start.


Steven

[generic_1]

Short answer NOOOOOOOOOOOOOOOOOOOOOOOOOOOO.

Those operating systems use different filesystems. You choose a presentation type on the EVA for as well although some of these are really aliases, it depends on the OS standards. Your going to end up with data corruptions, Your best solution if they are too pig headed to use enough space for each server individually is to do a NFS share from one system, but even then I would cringe. When it breaks tell them I told you so LOL.

[Vladimir Fabecic]

So you need NTFS rw from both OS-es. For linux there are captive drivers for NTFS (using MS drivers on linux). In that case you get read and write access on both OS.
Maybe it can help.

[Ivan Ferreira]

Be careful with NFS WRITE because is EXPERIMENTAL.

[Mahesh Kumar Malik]

Hi

1. It is workable options when OS on servers are of samw type because file systems are of same type.

2. For different OS environment , it is NOT recommended to have same lun shared by them since file systems are of different type. Best practise is to have seperate LUNS for different OS

Regards
Mahesh

[otukile]

Thank you all for your contribution. I now have enough information to convince them otherwise. Plus all the other options he can use. Thamk you