Does the number of drives I "can lose" w/o losing integrity change depending on how full the Storage Pool is?

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Does the number of drives I "can lose" w/o losing integrity change depending on how full the Storage Pool is?

jann

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I am just wondering...those of you who remember my horrific start w/my DS1520+ know that I did this wrong to begin with. Let's be nice to me and set that aside.

I put drives that were too large in my Synology to begin with and had to spend tons of $$ to go up from there when I expanded. (ie: Should've started w/my 8TB's, but inserted my 14's and 18's...thus I cannot convert my unused space to other usable space on a pool that is separate.)

What my question is is simple: With my (thank GOD) *ex* Drobo, if I had masses of extra disk space, it would then use extra space on some drives for extra parity and thus I could lose multiple drives and be fine. My Synology Pool is currently 52.73TB - with several of those drives NOT using 4Kn (my 16 & 18tb Exoses)...thus I lost about 2tb per drive. 4Kn rearing it's ugly head! Now that I am knowing where I messed up, I am wondering, can I remove one or more of the 18's since I am only using 30TB? ie: will the extra unused storage pool space on the drives allow me to "fail" more than one drive so I can then rebuild into another storage pool with 4Kn intact and move files over, then fail others until I complete the move?

Thanks!
ps: PLEASE don't flame w/"Start over. You can't do anything." not all of us can afford to buy 30TB of new drive space AND another Synology to create a new pool and move the data over. Thanks!

pps: the reason I'm asking is this vague statement on Synology's KB (I have 5 disks): "By selecting SHR Mode, Synology DiskStation will help you create an optimized storage allocation based on the number of installed disks. SHR volumes consisting of two or three hard disks provide 1-disk fault tolerance, while SHR volumes consisting of four or more hard disks can provide 1- or 2-disk fault tolerance." Synology KB
 

Telos

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By selecting SHR Mode, Synology DiskStation will help you create an optimized storage allocation based on the number of installed disks. SHR volumes consisting of two or three hard disks provide 1-disk fault tolerance, while SHR volumes consisting of four or more hard disks can provide 1- or 2-disk fault tolerance
No conflict. SHR is one drive protection; SH2 is two-drive protection. Select what you require.

Read on here
 

fredbert

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When you start out creating a storage pool then there really is only a one-way street for adding drives for data and protection, there's no reversing. Assuming you have spare bays, and SHR, then...
  • You can replace smaller drives with bigger to grow data.
  • You can add drives to grow data.
  • On SHR-1, you can add a drive to increase protection to two drives (SHR-2)
What you can't do, and keep the storage pool Healthy, is remove a drive nor convert a N drive SHR-1 to N drive SHR-2.

If you remove a drive from SHR then it becomes degraded and the level of protection is reduced by 1 drive.
 

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