i find it fun that when you buy a san or nas of lets say 20 tb, they say backup your data first.... IT IS the backups... lol how theh hell you gonana backup 20 TB ?

 

If in fact you're buying your NAS a backup, then that's fine.  But if it "IS" the backup, that implies you have the data stored somewhere else as well.    But a NAS by itself is NOT a backup ... it's simply a fault-tolerant server.    Like any other computer, it can (and someday will) fail ... so any important data on it should be stored somewhere else.

 

As for how you backup 20TB ... lots of ways.    I have over 40TB of data -- ALL backed up (most of it is in fact backed in two different locations).  I know a couple folks with over 100TB of data ... and it's also all backed up.

 

 

Thanks for all the replies and help.

 

The solution was much easier than I thought. After reading a post by JoeL I tried to re-construct the drive.

 

Stop the array

un-assign the red-ball-drive

start the array with it un-assigned (this will cause unRAID to forget its model/serial number)

stop the array once more

re-assign the drive (it will think it is a replacement for the missing drive and will re-construct onto it when you re-start the array)

start the array.

 

I cant find the exact post but it was the same idea.

 

I'm usually a lurker but its nice to see all the responses when a question is asked

 

Thanks

Re-constructing a "failed" drive onto itself is a good way to resolve an issue when it's due to a loose cable or perhaps loose connection in a hot-swap cage (re-seating the cables or the drive often lets this work fine).

 

But remember:  the drive failed.  There was a reason for that.  If the reason hasn't been resolved, then it's likely to fail again.  So ... be sure you have a spare drive of the same size available just in case it fails again.    Alternatively, after it's rebuilt, do a parity check and confirm all is well (no sync errors and no drive errors) ... and then replace your parity drive with a larger drive so the next time you have a failure you can use a larger drive 

 

From a smart report it looks like the drive failed due to over heating. Its a Seagate Barracuda Green that I took from one of their 2tb enclosures (there was a time I thought a 2tb drive would be enough  ) so I thought it had just died.

 

190 Airflow_Temperature_Cel 0x0022   078   044   045    Old_age   Always   In_the_past 22 (1 67 40 22 0)

 

I remember 2 of the fans on my case got disconnected after moving so that was more than likely the cause.

 

I did a parity check after the rebuild and all was well so Im going to to replace the parity then the failing drive (just in case)

I did a parity check after the rebuild and all was well so Im going to to replace the parity then the failing drive (just in case)

 

Good plan ... time for a couple 6TB WD Reds 

I did a parity check after the rebuild and all was well so Im going to to replace the parity then the failing drive (just in case)

 

Good plan ... time for a couple 6TB WD Reds 

 

Now why did you go an have to say that for?. I was happy enough going from 2tb to 4tb.

Would you mind PMing me your home address Gary, Im sure my missus will have a few choice words she would like to deliver to you in person if I start

buying 6tb drives 

 

 

Perhaps 4TB will be okay for now 

 

Note that at current Newegg prices, the 4TB Reds are $43.75/TB ($174.99), and the 6TB units are $50/TB ($299.99).  So it's only $6.25/TB extra to use the 6TB drives.    The issue, of course, is you have to buy a lot more TB's up front to use the larger drives 

Although I generally agree with the strategy to pay a premium for higher capacity drives, with the current prices it is quite a premium.

 

To add 10TB to an array with 6TB drives (assuming you have a 4TB parity today), you'd have to buy 2 6TB drives (one would be parity, your parity would become a data drive (+4TB), and the other 6TB drive would become another data drive (+6TB)). That would cost $600 = $60/TB.

 

To add 4TB to an array, you would need to buy one 4TB drive (=$135 for Hitachi CoolSpin current deal) = 33.75/TB. The equivalent cost (for 10TB) would be 337.50, $262.50 less than the 6TB route.

 

Another option to add 4TB would be to buy a 6TB drive (=$300) = 75/TB. The 6TB would become parity and the 4TB parity would become your data drive. Although pricey you are now positioned to add 6TB drives in the future without upgrading parity.

 

Adding to the decision is that the new 6TB drives, are, well, new. Their longevity and reliability is still in question. I remember when the WD 1T EACS/EADS drives ruled the world - they were very very reliable. But the 2TB versions of those drives were not nearly so. The same model number or marketing spin (e.g., "Red") does not mean that they automatically inherit the reliability of their smaller cousins. Until these 6TB drives prove themselves, users may want to be a little wary. Being the first on the block has an element of risk.

 

If you have a smaller case and looking at only a drive or two more before having to start upsizing existing disks (which is very pricey), I would be looking closely at the 6TB. But if I had several open slots and was looking at an economical way to add 4TB, and bide my time until the 6TB drives prove themselves and drop in price, I'd go the 4TB route today and reassess when the 4TB starts to get full.

 

Just my $0.02. Everyone's situation is different and there is no one size fits all solution here.

Clearly if you have a lot of extra drive slots and SATA ports, you can save $$ by using smaller drives and buying the cheapest you can find.

 

I consider the parity disk "sunk cost" ... it's the price of insuring a higher availability for your server by providing fault tolerance.  [unfortunately many folks seem to think this also means backups aren't needed ... but that's another story]

 

So the first question in upgrading is do you want to keep the current drive size limit in your system; or do you want to increase that limit to the largest drives available.  GIVEN that you have the appropriate parity drive, the cost "penalty" to move up from 4TB to 6TB drives of the same make/model (e.g. WD Reds) is, as I noted above, only $6.25/TB.    Since these drives also perform better than their lower capacity cousins (thanks to the 20% higher areal density); reduce both the power/TB and heat/TB; and require fewer SATA ports for a given capacity, I don't think that's a bad premium.

 

But I concede there's a one-time $300 cost to move to 6TB drives ... and all you gain from that is the old parity drive, which you can use as another array drive or (what I'd do) as an additional backup drive.

 

Regardless of what size you choose to buy, I do not recommend buying drives based on the lowest cost/TB ... reliability is a FAR more important factor than cost.

 

Sunk cost or not, the timing off the purchase certainly plays into it. Historically larger drives demand a premium for some period of time but relatively quickly the prices drop substantially.

 

I agree that buying reliable disks is the most important, but would also argue that the HGST cool spins are at the top of the reliability chart, and that a new model from any company is an unknown commodity.