MSA1000 and securepath

[Patrick Fang]

It will change path ? IF active HBA to fiber switch cable disconnect but fiber switch to controller cable is working.

[Ronald Hendriks]

As the MSA is active/passive, a HBA failure will failover the controller.

[Patrick_82]

Thanks for your reply.

Description:
1. i have two server which setup two HBA card and install securepath software.
2. two fiber switch
3. two controller in msa1000

Question:
How is controller If one server HBA card error but fiber switch to msa1000 is working.
You told me the controller will failover. So you mean this server will change path and another server (Even two HBA card is good) is also changing path ?

By the way,
1.I want to install Microsoft 2003 MSCS. When server booting, IF the first active HBA card connect to passive conroller and change path,What effect in first connect to active controller ?

2.Above procedure, if replace the msa1000 to 4-port Smart Array Cluster Stroage, will the same result ?

[Ronald Hendriks]

All other servers will change path (not a problem) However, mixing single path hosts and multi path hosts is not a good idea.
Single path hosts will loose connectivity.

[Doug de Werd · Accepted solution]

If you are using the multi-path SW and 4-port module with a Smart Array Cluster Storage, the behavior is different than with an MSA1000.

With an MSA and dual path, each of the HBAs in a server is essentially directly wired into one of the RAID controllers in the MSA. Think about it like this - assume that HBA 1 in all servers is connected to the active RAID controller in the MSA (via FC switch #1). In all cases, HBA 1 does not have a path to the second RAID controller. Conversely, HBA 2 in each server is only connected to the second RAID controller (via FC switch #2), and has no path to the first (active) RAID controller. So if ANYTHING in the path between HBA 1 (on any server) and the first RAID controller fails, then SecurePath will cause a failover to HBA 2, FC switch #2, and RAID controller 2 for ALL servers.

The Smart Array Cluster Storage (SACS) is different because it is using SCSI connections, rather than fibre. And the way the the SCSI connections are designed when using the 4-port module and multi-path SW is such that both of the SCSI HBAs in a server are logically connected to both RAID Controllers in the SACS (not just to one like in the MSA). So if SCSI HBA 1 in server 1 fails, the multi-path SW will only change the active path over to SCSI HBA 2, and only in that server. The other server is still using its SCSI HBA 1 as the active path, and the active (first) RAID controller in the SACS also does not switch over. In fact, because of this design it is possible (but NOT recommended) to run dual SCSI HBAs in each server, but still only have a single RAID controller in the SACS.

I hope this helps.

Thanks,
Doug

[Patrick_82]

Doug de Werd,

It's a clear explanation of the question.

Many thanks!
Patrick