iSCSI Multiple Connections to 1 LUN Read/write

[Photubias]

Hello,

We have several LUNs with each 1 target per LUN.
But we want 2 servers (initiators) to have access to the same LUN.
One of them needs to read what the other one writes.

But when ServerA writes to LUNA, it takes an hour for the file to be visible on ServerB.
Is this normal?

Greetings,

Photubias

[Ahead-IT]

Hello,

We have several LUNs with each 1 target per LUN.
But we want 2 servers (initiators) to have access to the same LUN.
One of them needs to read what the other one writes.

But when ServerA writes to LUNA, it takes an hour for the file to be visible on ServerB.
Is this normal?

Greetings,

Photubias

Same problem here

[To-L]

That seems normal since ISCSI targets are block based and not file based. Changes made by one person are not seen by another person working on the same LUN.
One way to see the changes quicker is to quit you ISCSI session and then reconnect to see the changes.

[Photubias]

OK, I want a centralized system where One Server writes to shared storage and other servers (at block level) kan read from that storage?

- Samba is not possible, because the ColdFusion servers need block access.
- iSCSI is not possible, because the changes are not (immediatly) visible in shared storage?

[Photubias]

That seems normal since ISCSI targets are block based and not file based. Changes made by one person are not seen by another person working on the same LUN.
One way to see the changes quicker is to quit you ISCSI session and then reconnect to see the changes.

OK, but when I want to run a Database on the iSCSI LUN?
When changes are made to that database, other servers can't see them immediately?

[vkeven]

OK, but when I want to run a Database on the iSCSI LUN?
When changes are made to that database, other servers can't see them immediately?

I never worked with cold fusion database but the thing you describe is probably support with some extension to coldfusion database and generally speaking when you want to access data on the same filesystem from more than 1 computer at the same time you need a network filesystem like Redhat GFS or something similar , doing this is not gonna be a simple one click task.

[To-M]

vkeven is correct.

To control this you need so called SAN File System programs. SAN file system solutions are very expensive.

Examples are listed below:
MelioFS:
http://www.sanbolic.com/melio.htm
IBM:
http://www-306.ibm.com/software/tivo...ducts/sanergy/
http://www.ibm.qassociates.co.uk/sto...rage-san-files
yste
m.htm
StorNext:
http://www.adic.com/ibeCCtpItmDspRte...24&item=121889
SGI:
http://www.sgi.com/products/storage/...e_systems.html
PolyServe
http://www.polyserve.com/
DataPlow SFS
http://www.dataplow.com