I am looking into a SAN system for a client and wanted to get some feedback regarding the current status of XSAN
1. First and foremost, Lion server OS and XSAN 2, is this combination something that is production ready? Should I present such a system to a client or should I consider and alternative software or hardware solution?
If we are production ready, then would the following be possible?
I would like to eliminate all single points of failure. In a SAN system I can identify several key components. In there you will find my confusion.
1. The Fibre channel switch create the fibre channel fabric- CAN use a secondary switch, which would connect to the second slot on my Fibre channel cards.
2. The metadata controller-CAN use a standby secondary (or I imagine as many as I want) back up metadata controller. How many can I use?
3. Client machines, these will actually be running file sharing services and allowing access for my users to connect. CAN use 2 more servers connected to the fibre channel switch to server AFP and SMB users. Could load balance by splitting up users or make only one available at a time.
4. The private switch-CAN user another private switch with a THIRD ethernet card, but mac mini's cannot use a third 1gb card, sooo what do I do? Mac pro's only??
Now confusion sets in...
5. Metadata RAID Array-How can I make this redundant, obviously it would be RAID 1 if a drive failed but what if this Raid unit physically fails, like blows up? Can I have a second physical Raid unit also acting as the Backup metadata raid array? Also in the setup Scripts the promise raids are built with Metadata Raid LUN and Storage Raid LUN in the same box? Do people use Dedicated Raid unit just for the Metadata LUN or are they combined into the same box in an ideal set up?
6. That leads me in the second part, the storage pool. Can I spread the data redundantly across two Raid unit but keep it 1 volume for my client server, so if the same thing happens, 1 raid unit blows up with my whole storage pool, the 2nd one already has the data redundantly written on it.
I am still reading up and would appreciate anyone's help in this matter. Thank you,
Actually looks like I was wrong, when I combine multiple raid 5 arrays together to make a single SAN volume it stripes the data across with no redudancy. So while a DRIVE may fail, and be replaced in the RAID 5 array, if a complete LUN goes offline I assume I lose all my data....is that correct? Any way to create a Raid 5 SAN so to speak, or a mirroed SAN? Or do I need to sync my data hourly across to separate XSAN volumes made up of RAID 5 LUNS...