TugboatBill Wrote:Strange that it isn't a topic that is discussed. planned for, or even experienced in the enterprise IT community. It must be important though.
You're wrong on this...
Been a lurker here for a while and had to chime in on this. I've only ready about halfway through this thread so pardon me if this has been settled.
I'm a SAN admin in a healthcare system. Currently we have about 1.2 Petabytes of all types of data ranging from transactional databases on high end fiber drives to large pacs images on mid-range SATA drives. Our primary storage vendor is a 3 letter acronym
. I only point this out to say that the large IT Storage companies do talk about bit-rot.
From day one, every SAN attached storage controller from the high end to the mid range (we don't buy low end) has had mechanisms to deal with bit rot built into the controllers themselves (NOT the disk drives).
Here's the description of what the hardware in our "lowest" class of storage controller does:
Code:
media scan. A media scan is a background process that runs on all
logical drives in the storage subsystem for which it has been enabled,
providing error detection on the drive media. The media scan process scans all
logical drive data to verify that it can be accessed, and optionally scans the
logical drive redundancy information.
So when you say that it's not discussed, planned for or experienced, my response to you if you are in IT is that you A) Have the wrong vendors or business partners, B) Aren't planning very well, and C) Have been very lucky.
I personally have never had to deal with a bit rot problem, but I suspect that the media scan processes are helping us with this. I do however have some peers in the storage admin profession who have been bitten by this because someone turned off the media scan process on their controller, and they didn't see it.
All that said, I'm a WHS convert to Unraid Pro at home. Haven't had any regrets so far in the 6 months I've been running it. I do however run two, and rsync between the primary and the secondary. As someone pointed out already, raid is not a backup mechanism.
HTH