preclear - did I do it right?

[BartDG]

I wrote this same post in a different thread, but I guess it wasn't the right thread for it, so I'm creating a new thread.

 

I'm very new to unRaid, this is my first setup.  First I had to buy a new motherboard because my Gigabyte board couldn't boot from USB.  Now I've got a new "old" Asus bord from eBay and I was good to go.

 

I created the boot thumb drive and installed unmenu and the preclear script.  Then I installed 3 disks: two 3TB Western Digital WD30EZRX (one of which is for parity) and one Western Digital 2TB WD20EARS.

 

I managed to install screen and ran three instances of Preclear.  The 2TB was obviously finished first, but when it was running, I immediately noticed something strange.  With the 2TB drive, the script said: "cycle 1 of 1, partition start on sector 64".  With the 3TB drives, it said : "cycle 1 of 1, partition start on sector 1"

 

The 2TB drive finished without a problem, after 35 hours.  The 3TB drives gave some sort of notification, something concerning the partition and I had to re-type "Yes" again.  But then it said it could not continue of some sort.  I fear now that instead of at sector 64, these partitions started at sector 1.  I found that strange because I did use the -A switch (preclear_disk.sh -A /dev/sda).

 

What did I do wrong?  I hope you can help me, because after more than 40 hours of pre-clearing, I really don't feel like redoing it.

 

Edit: oh, and does it matter that the motherboard uses an older bios which does not support disks larger than 2TB?  I've read in the past that Linux is capable of ignoring the BIOS setting and using it's own, but I'm not sure if it'll work in this case.  If not, then I will probably have to buy a SATA controller.  (the BIOS shows the 3 TB disks as 800 GB or something).

 

Thanks!

[BartDG]

Well, something must have gone wrong, because I've built the array now (3TB parity, 3TB+2TB data) clicked "start" and then clicked "format", and it's been at it for hours again now.

 

I guess the worst part is that it just says "formatting", but no status indicator or anything, so I don't even know if it's actually busy or if the system just hangs.  I guess I'll leave it overnight and have another look in the morning...

[garycase]

You haven't provided enough detail to say for sure ... but it sounds like you did just fine.

 

What's probably happening is that the system is doing the initial parity sync ... which can take many hours (for a 3TB setup I'd expect something in the neighborhood of 8 hours -- but the 2TB drive will make that a bit longer, as it will slow things down as the inner cylinders of the 2TB drive are reached;  then again with the 3TB units.      The format you did will also make the parity check a bit slower, due to drive thrashing while the format is being done at the same time as the parity sync [but only until the format is completed, which should happen within the first hour or so].

 

If you refresh the Web GUI, it should show the status of the parity sync -- and it's now been long enough since you started it that the two data disks should no longer show "formatting" ... check and see if that's the case.

 

 

[BartDG]

I guess you're right. When I got up this morning, I checked and it said (after screen refresh) that everything was fine!  Yay!

Only thing is: the green dot next to my second disk (the 2TB one) flashes on and off.  What does this mean?  Apart from that, everything looks peachy!

[itimpi]

Only thing is: the green dot next to my second disk (the 2TB one) flashes on and off.  What does this mean?  Apart from that, everything looks peachy!

That means the disk is currently spun down.  You will find that as a result there is also no temperature displayed as this is only available when the disk is spun up.

[BartDG]

Ah, great!  Thanks so much for the info!  But why didn't the 3TB spin down then?  I wasn't accessed for hours as well?  I thought unRaid always spun down its drives after a certain amount of time?

[garycase]

Probably hadn't been long enough since the last access for the 3TB drive.    The parity sync will finish with the 2TB drive LONG before it's finished with the 3TB and parity drives.  When you looked at it, the 2TB drive most likely had timed out and spun down;  the 3TB drives had not.    Look again and they're probably all spun down by now (unless you've been using the array).

 

[BartDG]

And so they have!  Thank you very much for your reply!