three windows 2003 servers need to share a lun

[blackrabbit]

Ok so I'm working on this project where we have a dell md3000i iscsi array and on that array are several luns (seems that the max the md3000i will allow me to create is 2TB). Anyway three different physical servers need to access these luns as one big 6TB disk to act as sort of a giant disk pool.

Do I need to implement clustering for these servers? I've never done anything like that before. Plus no one mentioned anything about clustering servers when they gave me this project. Any help would be appreciated. Thanks.

 

[nhidalgo]

Assuming these are windows servers connecting to the SAN, you can create one 6TB dynamic disk by combining the 3 LUNs. You should be able to map the 3 luns to all 3 servers, but you will need some type of clustering setup if they are all going to use the files at the same time or you may run into scsi reservation problems and just have general I/O problems.

 

[blackrabbit]

thanks thats exactly the answer i was looking for.

 

[baddos]

Three windows servers cannot use the same lun at the same time. If you need three machines to access the same lun, it would have to be a cluster, but the other nodes would have to be passive. It's a NTFS limitation.

 

[victorv]

hi,
just to speak ...

as BADDOS sayd, you cannot access a disk ( FC-lun, iSCSI,
SCSI...) from more than one server in concurrent mode:
the limitation is not HW or architectural, but comes from the filesystem (NTFS in Windows).

Also using Windows Cluster, JUST 1 server AT A TIME, can
acess the volume: the difference is that if you use cluster,
it automatically stops to access from one node and access
from the other node.

Also using other operating systems (as AIX), its cluster
called HCMP can access a volume by one node a time.
Using concurrent VG, you can use a DB (as Oracle) that
can access the same disk from more than one server simultaneously, but you cannot build a filesystem on this
volume ( as in windows, you see the disk, but don't create
a NTFS partition on it): you have to use Oracle in RAW mode.

Only OpenVMS (Digital -> Compaq -> HP ), can access a filesystem from more than on node: its "lock manager"
shares locks informations across the nodes, thing that
windows or AIX cannot do.

What you can do, is to build a home-made NAS: use one server
to access the the storage, also using dynamic volume, and
share the disk using normal SMB (windows share).
You can also use Linux to access the storage, and share the content to Windows, using SAMBA.

Linux Cluster + SAMBA ??

just to speak ...

ciao
vittorio

 

[blackrabbit]

Turns out they didn't want to use a cluster so I just made one server access the disks and then shared them. They said they were fine with that.