I've been setting up my second server for a few months and I just got the funds to get the HDs. Currently I have three old ones in there just to get it up and running but all of them will be replaced plus I'm adding two more. What's the best way to do this, do I have to replace parity first, wait until it's all done then replace each of the other drives one by one or is there a way I can do this faster?

Your subject line makes me think perhaps there is no data you want to keep. If this is true then you can just New Config with the new drives and let it build parity.

 

If there is data on one or more that you do want to keep then you will have to rebuild each to a new drive one at a time. Order doesn't matter except you might want to prioritize them based on which drives are the most likely to fail sooner. Of course parity will need to be at least as large as the largest data drive but it doesn't have to be first.

 

If you will post your diagnostics we can take a look and see if any drives are looking bad already.

 

Have you precleared or otherwise tested the new drives?

There shouldn't be data I care about, I'm running an ssd cache that has dockers and vms but the data drives are just there for testing/setup and they're old and small, basically left over from when I upgraded my current server. I purchase 5 brand new drives, 3 different orders so they all need to be precleared and tested which takes FOREVER. :-) If could install them and do this all at the same time that would be great!

There shouldn't be data I care about, I'm running an ssd cache that has dockers and vms but the data drives are just there for testing/setup and they're old and small, basically left over from when I upgraded my current server. I purchase 5 brand new drives, 3 different orders so they all need to be precleared and tested which takes FOREVER. :-) If could install them and do this all at the same time that would be great!

You can preclear multiple drives at the same time.

There shouldn't be data I care about, I'm running an ssd cache that has dockers and vms but the data drives are just there for testing/setup and they're old and small, basically left over from when I upgraded my current server. I purchase 5 brand new drives, 3 different orders so they all need to be precleared and tested which takes FOREVER. :-) If could install them and do this all at the same time that would be great!

You can preclear multiple drives at the same time.

 

I seem to recall that each drive will require a certain amount of memory while being precleared.  If there is 16GB of RAM-- no problem, 8GB should be enough, but 4GB would probably be marginal.  I would certainly stop any dockers and VM's while preclearing. 

If there's no data to be concerned about, you can simply install all 5 drives and do a New Config to directly build the new array.  You don't need to do anything r.e. the old drives except toss them 

 

... and in fact, if there's any data at all on the old drives you might want, you could simply attach them as an "unassigned device" and copy the data from that drive to your new array.

 

If you want to pre-clear the drives to test them (not needed for clearing purposes, but it's still a good idea to do a cycle to test the drives), you can indeed do several at once.  I've done 4 at once on a system with 4GB of memory, and it was no problem.  Not sure if 5 at a time would work; but you could certainly do 3, then 2, to get them all done much quicker than one at a time.

 

If there's no data to be concerned about, you can simply install all 5 drives and do a New Config to directly build the new array.  You don't need to do anything r.e. the old drives except toss them 

 

... and in fact, if there's any data at all on the old drives you might want, you could simply attach them as an "unassigned device" and copy the data from that drive to your new array.

 

If you want to pre-clear the drives to test them (not needed for clearing purposes, but it's still a good idea to do a cycle to test the drives), you can indeed do several at once.  I've done 4 at once on a system with 4GB of memory, and it was no problem.  Not sure if 5 at a time would work; but you could certainly do 3, then 2, to get them all done much quicker than one at a time.

 

How do I do this new config thing? Cables should be here today and my plan is to just take the old drives out, put the new five drives in and boot it up.

How do I do this new config thing? Cables should be here today and my plan is to just take the old drives out, put the new five drives in and boot it up.

Tools - New Config

Ah, cool. So I shutdown, put all new drives, reboot and choose this option? I'm assuming the array won't start because of everything that has changed so it will be easy to get to this option.

Ah, cool. So I shutdown, put all new drives, reboot and choose this option? I'm assuming the array won't start because of everything that has changed so it will be easy to get to this option.

The array won't start because there will be too many missing disks, the old disks that you had assigned previously. New Config will make you select new disk assignments, then when you start the array it will format the new disks and rebuild parity.

 

You should preclear/test the new disks before you do this because they can't be precleared after they have been assigned.

 

If you have a problem post a screenshot.

Thanks, is using the preclear app still the best way to preclear? I'm running the latest 6.2

A note r.e. pre-clear ...

 

(a)  If you do a New Config, there's no need to clear the drives, so that function of pre-clear is unnecessary.  You could, in fact, simply install the drives; do a New Config; and Start the array without ever bothering with the pre-clear function.

 

(b)  That said, the OTHER thing pre-clear does is provide a basic test of the new drives -- ensuring every sector can be read; writing zeroes to the entire drive; and then confirming those writes were good.  So it does give you some assurance that the drives are good.  It's not a bad idea to test a drive before putting it in service, and pre-clear does do this.  You can also do this in other ways -- e.g. you could attach the drives to a PC and run the manufacturer's testing utility (I use WD's Data Lifeguard regardless of the make of the drive).

 

©  You could also just skip the testing altogether.  The simple act of doing a parity sync, followed by a parity check, will test the ability to read every sector of the drives and will confirm that you can write every sector on the parity disk.  The only thing that won't be "tested" as a result of this is the ability to write to all sectors on the data disks.  In fact, if the sectors are all good (as will be confirmed twice -- once during the parity sync and once during the subsequent parity check) -- it's almost certain they're fine.  And of course should there be any issues that you identify when you start populating the array, it IS fault-tolerant, so you won't lose any data anyway.    The downside of not testing the drive before doing this is if you may not identify "infant mortality" issues that would be easier to resolve by replacing the drive immediately.

 

Basically, I'd recommend testing the drives before putting them in service, but it's not an absolute requirement, and the risk of not doing so is very small.      But it's easy enough to simply install all of the drives; boot to UnRAID, and run the pre-clear utility BEFORE you assign any drives to the array.  You could probably just run 5 instances of it and do them all at once -- but if you want to be a bit "safer" I'd do 3 at once to ensure you don't hit any memory allocation issues during the process.

 

Great response, thanks. Since this is my second server and It's been all but idle for months now I can wait another week to check the drives. :-)

 

How much memory is needed, I have 64GB so I figured it would  be safe to run preclear on all five drives?

Great response, thanks. Since this is my second server and It's been all but idle for months now I can wait another week to check the drives. :-)

 

How much memory is needed, I have 64GB so I figured it would  be safe to run preclear on all five drives?

 

Absolutely!  One drive can be precleared in 2GB, so figure from there...

 

Last time, I did a large Drive, it took a bit over 70hours to do 3 cycles on a 3TB WD RED drive.  I was actually trying to put a few hours on the drive before I committed it to an array.  I figure 50 to100 hours will find most drives that are going to fail (infant mortality) before the end of their normal expected life.

Yes, you can easily do all five at once.  As I noted earlier, I've done 4 at a time with no problem on a system with 4GB of RAM ... so with 64GB you're more than fine 

 

I don't think you need 3 passes, but it certainly won't hurt.  I generally do two full runs of WD Lifeguard's complete set of tests on all new drives, and have NEVER (knock on wood) had a drive fail after it passed that regimen.  I HAVE  found a few "dead on arrival" drives that failed during the initial testing.