On Wed, 20 Jun 2001, Thomas Heffron wrote:
- You can't have the quorum resource there because (in MSCS) the
cluster will never be created. The first machine will come up and can't physically own the volume. So, it only tries to join a cluster (which doesn't exist yet).
Ah, so this is not a general property of a quorum resource, just the particular implementation that Microsoft decided to use in MSCS... it cannot take exclusive ownership of a CIFS volume, since it relies on the lower level SCSI protocol to achieve that. I assume there are other third-party products that implement this differently (lock files over NFS/CIFS, heartbeat monitor, etc.)?
- Many Cluster aware apps will want their application on either local or
shared storage. For example, MS SQL 7.0 _highly_ recommends that the binaries and Master DB (the DB about the other DBs) are on direct attached storage. If these two things aren't available then you can't start the SQL service (novel concept, huh?)
That is the recommended configuration because Microsoft fears that NAS is less reliable than local storage? Or perhaps to avoid a performance bottleneck because the master DB is accessed on every transaction? I can't think of any valid reason why the binaries can't reside on a network drive... if the network is not available, and your tablespaces are stored there, there is no use starting up the database anyway.
- This leaves only logs and application data on the Filer - which is the
meat of the app anyway - and probably what you're more intersted in.
Right... I'm trying to justify a vendors claim that we need hundreds of gigabytes of local RAID storage just because they use MSCS... need to dig deeper to find out what is BS and what isn't.
The problem comes whe you start talking price... Most people ask why they would consider using Filers for data storge if they _have_ to purchase and configure a shared SCSI disk shelf (and associated peripherals) to use MSCS anyway.
True, but there are plenty of other clustered products out there (our Checkpoint firewalls, our F5 load balancers, etc.) that don't need a shared SCSI disk, so obviously it can be done, but in this case, Microsoft chooses not to...