RAID Level

[KRS1974]

Just a question my TS-453A has 4 x 1tb drives in it.

Which would yo recommend for Home Media server and Storage photos etc ??

Raid 5 with hot Swap
Raid 6 with hot Swap

I will be Trunking all the LAN ports for better speeds so want to select the best RAID with tollorance.

[dolbyman]

with hot swap?..you mean hot spare

I'd say raid5 with 4 drives (no spare) and regular external backups

[KRS1974]

Why no hot spare ???

This a performance thing or disk space thing ??

[dolbyman]

why would you want a hot spare ?

you have one drive redundancy on raid5 ..plus your backups

also raid6 plus hotswap wouldnt even work on your 4 bay nas

[KRS1974]

Hi

Thanks for your input raid6 was a typo should have just been raid 6 without hot swap.

the general thinking seems to be raid5 without hot swap as while the hot swap is fixing the dying array another disk could fail an no backup performed.

What's your thoughts on using raid 6 instead of raid 5 ?? is there a vast hit on read / write speeds ??

[dolbyman]

the RAID6 with double parity should not horribly impact the performance, you will defiantly hit the gigabit barrier and trunking only helps if transferring with more than one client at a time

So no matter if RAID5 or 6, don't forget your backups

[Don]

With 1tb drives I would go with a 4 drive raid 5 with a cold spare. If you were using 8tb drives I would go with raid 6.

[dolbyman]

why waste the space with a coldspare ?

get a 4TB external backup drive for worst case scenarios

not saying cold- or hotspares are not usefull on larger/more disk systems .. just not for that case

[Don]

What space is wasted? 4 x 1tb RAID 5 with a 1 tb drive sitting in a draw.

[dolbyman]

oh I thought you meant coldspare inserted (so rebuilding on demand not automatically)

We always defined coldspare as a non automatic rebuilding hot spare (lol) .. the controller would also keep it powered off (hence coldspare)


So I thought that you meant for the OP then:
3x1TB RAID5 + Cold Spare = 2TB usable

RADI5 with an extra drive in the drawer is always a good idea (@OP still no substitute for backups)

[Don]

(@OP still no substitute for backups)

Agreed!

[KRS1974]

Thanks for all your input I have built it with RAID 5 static without hot spare and a 1TB in the draw just in case.

[P3R]

We always defined coldspare as a non automatic rebuilding hot spare...

We?

Anyway I find that a very odd definition of a "cold spare" as the only way to keep a disk cool is to not have it in the chassis.

Unless the NAS is powered off the disk will be spinning along with the other disks and never be cool, it just isn't used. The disk will be stacking up Power_On_Hours and using power that could be better used anywhere.

I guess you could call it a warm spare but I can't think of a reason for using a disk that way...

[dolbyman]

We?

My old company I used to work in

Anyway I find that a very odd definition of a "cold spare" as the only way to keep a disk cool is to not have it in the chassis.

If taking the chassis apart is a large pain in the "behind"(tightly placed IBM isieres tower servers where you can't easily open the sides without moving them), you (or we) rather put some extra drives in when you have it appart for maintenance, but to not have the drives age, you tell the controller to not keep them "ready", so to activate them you just need to access the RAID controller and mark them active (and then assign them). [/quote]

Unless the NAS is powered off the disk will be spinning along with the other disks and never be cool, it just isn't used. The disk will be stacking up Power_On_Hours and using power that could be better used anywhere.

Yes on QNAP that is true .. if it is plugged in all drives run all the time

I guess you could call it a warm spare but I can't think of a reason for using a disk that way...

yeah .. see above