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anthonyfromheadford
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Q: Xsan Migration

I was asked by a new client to look at upgrading their SAN. However despite my years of mac knowledge I have never setup xsan. Now I have always been advised you need one meta data controller and one backup meta data controller and one File Server Plus whatever raid storage is required. This site has one Xserve G5 and three raid units. They claim that each raid unit has its own LUN. if that is the case is the data stored on each array as normal data is stored? in otherwords can I just plug the raid units into a machine not running XSAN? I suspect not but Hopefully someone here knows.


Mac OS X (10.7.1)

Posted on Oct 17, 2011 2:37 PM

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anthonyfromheadford

Q: Xsan Migration

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  • by Christopher Collins,

    Christopher Collins Christopher Collins Oct 18, 2011 12:13 PM in response to anthonyfromheadford
    Level 1 (50 points)
    Oct 18, 2011 12:13 PM in response to anthonyfromheadford

    Please don't take this as me being flippant at all, but there is a LOT to Xsan if you want to do it right. Go here and start with the documentation provided by Apple http://www.apple.com/xsan/resources/. If I were you I'd consider punting this to a service provider that has more experience with this. I know its a new client but if you do it wrong (which there is a really good chance you will your first time) you are going to end up with a customer that isn't happy with you anyways.

     

    And to answer your basic question, if they are running xserve G5s and old Apple RAIDs it's probably time to get new equipment. Xsan is stored in a unique way on data arrays and is not the same as direct attached storage. Data is written to storage pools. Pools are collections of LUNs. Thus data is striped across all the LUNs in a pool. Metadata is written to it's own pool, etc. Which all basically means nope, you can't see the data on anything but a working Xsan system.

     

    Since this seems from your description to be a pretty old SAN and probably small amount of storage, is this a video customer or is their SAN used generally for file sharing? If for the latter, it may be a lot smater to just get a new bigger RAID, direct attach, and just use file sharing. You'd better utilize the amount of storage since you won't have to carve up the RAID as much and loose space on LUNs exclusively used for metadata, etc.

     

    Read the documentation and it will make a lot more sense.

  • by anthonyfromheadford,

    anthonyfromheadford anthonyfromheadford Oct 18, 2011 12:38 PM in response to Christopher Collins
    Level 1 (0 points)
    Oct 18, 2011 12:38 PM in response to Christopher Collins

    Hi Chris. 

     

    Thanks for your opinion.  I do appreciate it.  Unfortunately, I live in Ireland.  We are a small country and the person that installed this in the first place was 'the expert' now it is quite clear that they weren't.  A lot of people are winging it here.  One meta data controller and no backup in a San is laughable.  I unðerstand that but I wanted to be sure.   I have 20 years mac knowledge that exceeds most engineers I know. In ireland there are really only 3 guys to deal with one being me.  I for one would definitely advocate one mac dealer to deal with Xsan,  because as you pointed out experience is everything in this game.  As the 'expert' who set this bag of cack up has now gone to a production house (god knows how they get these jobs) he is no longer around to pick up his mess.  I or one other are left with it. Thank you for confirming my fears.  I will need to build in an Xsan course on the cost of the upgrade for sure.    It's nice to get an honest answer, thanks again.   Tony