I have been looking at different LSI MegaRAID cards for my undergoing SAN build, and I couldn't find any information about RAID controller redundancy, I have seen number of storage vendors ex, EMC equallogic they have Active/Active RAID card.

is it possible to setup similar controller setup?

if it is not possible, can I buy 2 cards from similar vendor/model/firmware and have it work as a drop in replacement/spear??

what is the recommended setup?? my plan is to setup this SAN up and not to visit that Data center ever!!!

  • 1
    Redundant controllers require dual-ported drives. These are prohibitively expensive. – adaptr Mar 8 '12 at 8:43

Vendors produce SAN equipment with their hardware because it works. Trying to build your own “SAN” is going to be a disaster waiting to happen.

The reason HP, EMC, Dell etc have such a high price tag on there SAN hardware is because it is thoroughly tested, you get warranty (Normally 4 Hour Return to Service) You could never GURENTEE RTS if you used off the shelf hardware.

I would persuade any person that tries to skimp on this and get the product that is proven. I know this isn’t always the best option for a business but can you cope with the downtime when you can’t fix it?

  • Strongly agree! but I will certainly do that when I have 20 -80K to spend on a san! – Dean Kamali Mar 8 '12 at 6:27
  • 1
    @DeanKamali: You'll drop at least $20k on your own hardware to build any sort of decent DIY SAN. – womble Mar 8 '12 at 6:45
  • @DeanKamali Ify ou agree then why not up vote? – Zapto Mar 8 '12 at 6:52
  • I'm able to setup my own with decent hardware for about 5K which includes more drives / redundant power/ decent RAID card with SSDs :) I'm looking for away I could create redundant RAID card! the current recommendations is to have a spear card handy. – Dean Kamali Mar 8 '12 at 15:36

If you are building a storage server to share with other servers, you might want to consider something other than a block-based protocol which would define it as a "SAN"- many applications like oracle and VMWare support NFS now. That said, even if you allow block, the raid controller you use on the back end will always be active/passive. Active/active with traditional RAID levels is only available on real storage.

That said, you might be able to use ZFS instead of RAID and get the same result. I am no expert on it, but it has a write-anywhere data striping system that's supposed to be better that traditional RAID.

  • ZFS prefers JBOD with out underlying RAID so it can track where the data blocks, the parity or mirrored blocks, and the checksums are stored for end to end block checksumming. I've heard stories of people using RAID under ZFS and actually finding faults in RAID controller firmware due to the checksumming of ZFS exposing them. – Thomas G Mar 9 '12 at 19:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.