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ZFS SAN: Growing pains

As I mentioned previously, I’m outgrowing my existing OpenFiler SAN which I’ve been using for several years now.  It has a capacity of ~3.5TB and is used as an iSCSI target for my VMware Lab, as well as general file storage.  It has been plagued with consistency problems as growing pains, requiring major “fork lift” upgrades with substantial down time any time I want to expand the RAID array or install updates.  With the holiday season rapidly approaching, and some quality time off coming my way, I think it’s time to work on a new SAN and retire the old one to a backup and non-”system critical” role.

Below is a list of the primary issues I have with the existing system, and issues that I would ideally like to be able to resolve:

  1. Running out of storage with no room for additional disks
  2. Inflexible Linux software RAID-5 configuration; difficult to modify/grow an existing RAID array
  3. Problems with snapshotting with present configuration (partly my fault, but also poorly implemented in OpenFiler)
  4. The system is LOUD so it must be continuously powered down for the sake of sanity
  5. No updates from the OpenFiler project in years, looks like the project is dead
  6. Issues with data integrity.  I have had issues with corrupt data when the power goes out.
  7. Inability to verify data integrity without using something like MD5 hashes
  8. No free PCIe slots.  I have a Fiber Channel HBA I would like to play with

This obviously leads into my next question; namely what do I want from new new system?

  1. Plenty of drive expandability and room to grow in the future
  2. Ability to upgrade existing drives/volumes when larger disks become available
  3. Ability to verify data on disk and prevent “bit rot”
  4. Painless snapshotting
  5. A quiet system.  This would allow the system to remain powered on 24/7
  6. Email notifications for failed disks, disk integrity issues, and power outage notifications
  7. Data redundancy, with “zero” downtime
  8. Upgradability, with “zero” downtime
  9. Plenty of hardware upgradability
  10. Service my needs for the next 4-5 years (base hardware that is)

Quite an extensive list indeed.  While some of the items might appear minor (eg: noise), this system will live in the basement and shouldn’t cause auditory unpleasantness.

I will be using some of the hardware from the existing SAN for the time being to allow me to save some money in the short term.  In particular I will be using the systemboard, RAM, and CPU.  The existing Promise RAID cards will remain in the old SAN and I will be using a new LSI SAS 6.0G/s HBA (non-raid) for the new system.  More on this later.

OpenFiler is a linux based storage appliance and has served me well.  However with lack of updates for years and issues with expandability and data integrity, I will be replacing it in favor of Solaris combined with ZFS as my Storage OS.  In the next post I will talk a bit about ZFS and why it’s such a great fit for my requirements.

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