Reallocated sectors

[Strega]

My monthly non correcting parity check completed with no errors but I got a warning of reallocated sectors on disk 4. The dashboard shows a thumbs down but it's still mounted and seems to be running fine.

 

Before I do something stupid, I was hoping someone smarter than me can take a look at my diagnostics and tell me if the drive needs to be replaced or just watched to see if the sectors increase. If the advice is to replace, I was thinking of swapping my parity drive for a larger one and replacing disk 4 with the current parity drive. What I question about that is the parity drive is one of the oldest in my array and I'm not sure it would be wise to do that.

 

Any advise would be most welcome, thanks in advance!

tower-diagnostics-20211002-1908.zip

[Frank1940]

Your Re-allocated  sector count is 8.   The drive has 33,410 hours (~ 3yrs, 10 months) of power-on hours-- and elderly dive but not unduly so.  The question you probably need to be able to answer is were all of these sectors found in the last Parity check or have they been accumulating  over a period of time.

 

Now, I am a very conservative, semi-paranoid type of person.  What I would do is replace the drive.  I would then run that old drive through three preclear cycles and see what happens to it.  If the count didn't increase, I would probably keep it as an emergency spare.     (As a point of reference, I have a drive in my Media Server with 74220 hours (8y, 5m, 17d, 12h) with no re-allocated sectors so far!  And, by the way, that drive is one of the infamous Seagate ST3000DM001 drives!  Of course, originally, I had four or five of these Seagates and this is the last one left...) 

[Frank1940]

41 minutes ago, Strega said:

If the advice is to replace, I was thinking of swapping my parity drive for a larger one and replacing disk 4 with the current parity drive. What I question about that is the parity drive is one of the oldest in my array and I'm not sure it would be wise to do that.

 

You need to think this through before you make this move.  Do you really have a need for additional storage space in the next 12-to-18 months?  I would never have jumped to a 12TB parity drive when I had 10TB data drives (or I never would have purchased a 10TB data drive when I had a 12TB parity drive)!   If you buy a new parity drive, I believe that largest drive you can get is 16TB at this time.  Perhaps by the middle of next year you might be able to get a 20TB drive which makes more economical sense when replacing data drives to gain additional storage space---  $$/TB of additional storage space.  (If spend $300 for a drive to get an additional 2TB of storage space, you pay $150/TB.   If you pay $400 for 6TB of additional storage space, you pay $67/TB!)

[Strega]

Yes, those sectors were found in the last parity check.

 

No, I don't really need the extra space right now as I still have a little over 7TB of space left.

 

Thank you for pointing out the giant flaw in my plan (price/TB), I failed to think of that!

 

Seagate has released their 18TB Exos drives which can be had for about $400 (bare drive) but who knows if it has the Seagate 5 year warranty. It seems to be a crap shoot with bare enterprise drives. Funny thing is 10TB  IronWolf drives go for $315 or so. It looks like I'll be giving a Toshiba enterprise drive a whirl as they are around $225 for a 10TB and Newegg says they have the manufacturers 5 year warranty.

 

I'm taking your very good advice. As soon as I do a little more research on what 10TB drive I want, I'll replace that drive and then see what it looks like after 3 preclear cycles.

 

Thank you Frank1940!

[Frank1940]

5 hours ago, Strega said:

'm taking your very good advice. As soon as I do a little more research on what 10TB drive I want

 

If you  have a 12TB parity, look for a 12TB data drive to replace that 10TB.  You already have to buy the first 10TBs so the cost for the extra 2TB is only the difference in cost between the two drives.  (I have always considered warranties as tool of the marking department.  They imply nothing about the reliability of the drive model itself.  Its length is a tradeoff of increasing current revenue vs future warrant costs.)    (I started out with 1TB drives, moved onto 3TB drives and finally to 6TB drives.  Each time, I made the shift, the cost of the new larger drive was about the same of the initial cost of the previous drive.  I realize that there was an artificial 'sweet' spot created when folks were shucking 8TB USB drives but that I still think that was a marketing tool to dump certain excess inventory of certain models of 8TB drives.  They could bury any drive model inside that USB case as long as it was an 8TB drive!)

 

EDIT:  Plus, if you do exercise the warranty on a drive, you will most likely get a "refurbished" drive.   If you spin your Unraid drives down, they seem to last a long, long time once they get by the infant 'mortality' stage.  Google 'bathtub curve' if you want to see what the failure curve of hard drives looks like. 

Oh, one more thing, Unraid does not use its array drives in quite the same way as a normal RAID setup.  So the 'Enterprise' drives do not seem to be really required for long drive life.  Plus, I again suspect this designation is more of a marketing tool than a true indicator of a superior design. It is old "FUD" marketing (Fear, Uncertainty, Doubt) ploy.  IBM first used it 60 years when third party vendors were finally allowed -- A government-mandated consent decree as I recall-- to install tape drives onto IBM mainframes.)

Edited October 3, 2021 by Frank1940

[Strega]

8 hours ago, Frank1940 said:

 

If you  have a 12TB parity, look for a 12TB data drive to replace that 10TB. 

 

Nope, I have a 10TB parity. That's why I was thinking of upgrading parity and then using the parity drive to replace disk 4. My thinking is that if other ageing drives start needing to be replaced I would be able to replace them with larger drives. If I don't need the extra space right away I could shrink the array, less disks less problems.

 

The reason for considering enterprise drives is it seems for an equal size the enterprise drives (bare drive) are a bit less expensive than NAS drives (retail?). The longer warranty is just a bonus (if it's honored on bare drive).

 

I'm in the "keep everything spun up" camp. The only time I've lost equipment (power supplies and drives) is when the were spun down or powered off.

 

Now you have me thinking (which is always dangerous). After a quick check, 14TB seems to be the sweet spot for price/TB but I don't think it's enough of a jump up in size to make sense. I think 20TB drives will be out some time next year and that jump in size would make sense to me.

 

This may take a little more thought, or advise lol

Edited October 3, 2021 by Strega
Clarity

[trurl]

13 minutes ago, Strega said:

upgrading parity and then using the parity drive to replace disk 4

https://wiki.unraid.net/Manual/Storage_Management#Parity_Swap

[Frank1940]

55 minutes ago, Strega said:

After a quick check, 14TB seems to be the sweet spot for price/TB but I don't think it's enough of a jump up in size to make sense.

This is a choice that only you can make.  How fast are using up Storage space?   It took me about ten years to accumulate 18Tb of 'stuff' on my Media Server  (out of a current total of 24TB).  What I tend to do when deciding on what should be my parity size for a potential upgrade is to look to see what the total additional storage space I will get with a certain size parity drive setup without increasing the drive count.  I also figure that I will have old data drives fail and their replacement (as I plan on purchasing future data drives based on the parity drive size) will add the additional storage as the years go by. 

 

In the case of my Media Server, I can see no reason (as an example) to make my parity drive size of 14TB as the first data drive replacement would provide sufficient storage space for a minimum of three years (to a possible six years).   And I already have three 3TB drives in that server that are over six years old.   So I can expect that these drives will need to be replaced in the few years.  SO I would be adding storage capacity faster than I was using it up.  With my current 6TB parity setup, I can go to 36TB of data before I need another major jump in parity size.  That is a good five to seven years down the road!  One thing I am reasonably certain of is that cost jumping to whatever new parity size will cost less than it does today.

 

Back in 1989, When I bought my first hard drive of 10MB  (that's right!!!) for cost of (approximately) $500.00, I never dreamed that in 30 years there would 18TB drive for $400!  (The PC I installed it in had two 5-1/4" floppy disk drives and those floppy disks had a capacity of 720KB.)  Back in those days, the very idea of an individual needing that much storage space was simply inconceivable.   I doubt if there was any data processing center in the entire world, in those days that had that much data stored (and if they did, it would have been on magnetic tape). 

[Strega]

After thinking about it, I don't need the additional space right now. I have a little over 7TB of space and since I've been converting the full disc ISO's to movie only MKV's on my server (it's primarily a media server) I've been reclaiming space. I just added 26 movies and didn't touch the 7TB, just used up the reclaimed space (and still have some of that left) and I still have movies and TV shows to convert. When I actually do run out of space I'll decide what size to move up to, do I want to consolidate etc., at that time. Hopefully you'll be around to offer some more of your great advise!

 

I remember 5 1/4" drives, that's all my first computer had. I remember being so happy when 3 1/2" 1.44MB floppys became available. I think my first hard drive was a Quantum but I don't remember the size.

 

I'm going to stick with your original advice and just replace disk 4 and hopefully be able to clear it and have an emergency spare.

 

Thanks again Frank1940, I told you getting me thinking was dangerous lol