RAID expansion question

[stgeorge]

So I have a pro6 currently fitted with 3X1TB hard drives in some form of the default RAID setup. I have 3 empty bays.

I also have a Duo that I use as a media server, specifically for movies, and it previously had 2X 500Gb drives in RAID which were at capacity. I'm currently upgrading those to 2X1TB drives and decommissioning the 2X500Gb drives.

...but a thought occurred to me- I checked the HCL and these 500Gb drives are checked out on the pro6... would it make any sense to add them into two of the three empty bays on my pro6 ?
I've currently hotswapped one of the 500Gb drives with a new 1Tb drive and letting it initialize (i.e. resync with the other 500Gb) then I'll replace the other drive in the same fashion.

Once I swap these two drives out, I understand putting them into my pro6 would necessarily wipe all the media, which is fine at that point. I guess I'm just curious if adding 2X500Gb drives helps when you have 3X1TB in RAID. I don't really understand exactly how RAID would handle that and/or whether it would make any sense.

[fastfwd]

StGeorge wrote:
I'm just curious if adding 2X500Gb drives helps when you have 3X1TB in RAID.

If you were adding 1TB or larger drives, they would just automatically increase the size of your array without affecting your existing data, while the NAS remained online and accessible. You cannot do that automatic expansion using the 500GB drives, though, because they are smaller than the largest drive in your Pro6. To use the 500GB drives, you'd have to backup all your data from the Pro6, install the new drives, factory-default (i.e., reformat) the Pro6, then restore your data.

Your Pro6 currently has a 2TB array (which is probably displayed in Frontview and Windows as something like 1832GB, but that's just because drive manufacturers use a different definition of "TB" than everyone else). If you inserted the two 500GB drives and did the whole backup-format-restore procedure, you'd end up with a 3TB array.

If that sounds like a lot of work for a 1TB storage increase [it does to me, especially since 1TB drives can be had for around $50 with free shipping], but you don't want to discard the 500GB drives, perhaps you could put them in USB enclosures and use them for external storage or local backups or something.

[StephenB]

I agree - a lot of work for not much gain. If you want/need the extra space in the Pro, I'd just add a single 1 TB drive, leaving two empty slots for future expansion, instead of just one.

[stgeorge]

Thanks for the thoughts- I tend to agree, just didn't want to toss these 500Gb drives (or take 'em out back to the chopping block, if you know what I mean).

Separately- I just finished swapping out these 500Gb drives for 1TB drives in my Duo and for some odd reason, they are listed as 1Tb drives, but are keeping the previous 461Gb allocation ?
Clicking on Frontview -->Volumes-->Volume Settings each new drive is listed as 961Gb in its description, but overall it is showing 95% of 461Gb allocated utilized. The available space does not appear to be recognized yet.

The condition is being reported as fully redundant, so that is good.

How do I get my old Duo to recognize the new space though?

[StephenB]

If the resync is finished, try rebooting the duo. You may need to do this more than once.

[stgeorge]

That did it ! Thank you.

Data volume has been successfully expanded to 925 GB.

[zamboni]

I've added smaller drives to my Pro Business, shocked that it happily accepted them. I've added 1.0 TB's after expanding to 1.5 & 2 TBs - no loss of data.