Hey everyone,

I finally received all my computer parts to begin my build for my unraid box.

 

I've done a lot of reading and I think I understand most of what I need to get the system up and running.

 

I do just have a couple of questions though about pre-clearing the drives.

 

Do I need to specify either "-a" or "-A" when I run preclear_disk.sh?

 

I'm going to be putting 2X3TB WD Reds in the system(brand new) and 1X2TB WD Green(used) into the tower to start.

 

What is the recommendation for this?

 

From what I read it sounds like pre-clearing the drives is necessary but do I really have to do it?

 

Thanks for the help!

Do I need to specify either "-a" or "-A" when I run preclear_disk.sh?

 

I'm going to be putting 2X3TB WD Reds in the system(brand new) and 1X2TB WD Green(used) into the tower to start.

Those options are not relevant to 3TB disks.

From what I read it sounds like pre-clearing the drives is necessary but do I really have to do it?

If you do not do it beforehand then it will get done when you add drives to the array which can mean the array not available for use for a long time (hours/days).  Adding pre_cleared disks to an existing array means the array is only unavailable for a minute or so.

 

In addition it is always a good idea to test the drives before adding them to the array and the pre_clear script does this.  You do not want to find a drive is not reliable after you have copied a lot of data onto it.  Just because drives are new does not mean they will not fail - in fact one of the most likely time to fail is in initial use so again the pre_clear script tends to help identify such drives.

Hey everyone,

I finally received all my computer parts to begin my build for my unraid box.

 

I've done a lot of reading and I think I understand most of what I need to get the system up and running.

 

I do just have a couple of questions though about pre-clearing the drives.

 

Do I need to specify either "-a" or "-A" when I run preclear_disk.sh?

If drive is > 2.2TB no < 2.2TB maybe

I'm going to be putting 2X3TB WD Reds in the system(brand new) and 1X2TB WD Green(used) into the tower to start.

 

What is the recommendation for this?

Largest drive has to be parity so one 3TB drive will be parity.

From what I read it sounds like pre-clearing the drives is necessary but do I really have to do it?

How important is your data?  How long do you want your array to be offline when adding a new drive to your array?

If you value your data and do not want to have your array unavailable while unRAID zeros the drive then YES it is necessary.  Besides zeroing the drive while leaving the array still accessable - it will exercise the drive and make sure it won't go bad on you right after you add it to your array.  Preclear still doesn't prevent all errors but it does make them less likely to occur after you add a drive to your array.

 

From what I read it sounds like pre-clearing the drives is necessary but do I really have to do it?

If you do not do it beforehand then it will get done when you add drives to the array which can mean the array not available for use for a long time (hours/days).  Adding pre_cleared disks to an existing array means the array is only unavailable for a minute or so.

 

Thanks for the help guys!

 

Well I won't have an array when I first build this so I will just go ahead and pre_clear them before I set the array up.

 

 

Since you're using 3TB drives, you're obviously using v5 -- so you do NOT need any parameters with Pre-Clear regardless of the size of the drives ... it will automatically use the 4K alignment.

 

Pre-Clearing the drives is, as already discussed, the best choice ... but currently it's also the only choice, as there's a problem with the clearing function in v5RC12a (i.e. it doesn't work !!).    But if you pre-clear the drives, they'll add with no problem.

 

Enjoy your new UnRAID server 

... FWIW, the v5 clearing issue is detailed here:

http://lime-technology.com/forum/index.php?topic=27221.0

 

I've notified Tom and posted the note in the link so warn others; but a few folks have still tried to add drives without pre-clearing and subsequently posted questions here about why it wouldn't work 

Thanks for the info. I have the drives currently preclearing.

 

I used 'Ctrl+A c' to get to a new screen to get the second drive going, but how do I check on the first drive? I tried 'CTRL+A n' and Ctrl+A p' to switch screens but it does nothing.

 

I'm using the latest download of Unraid.

 

Is the command different in the latest version?

 

Thanks!

Did you actually start 'screen'? It has to be installed and then started by running 'screen' before you can switch to a different screen. It is not actually part of unRAID so no it hasn't changed in this version of unRAID.

 

Tapatalk from CM10.1 Kindle

 

 

Did you actually start 'screen'? It has to be installed and then started by running 'screen' before you can switch to a different screen. It is not actually part of unRAID so no it hasn't changed in this version of unRAID.

 

Tapatalk from CM10.1 Kindle

 

I must have missed that part. Pressing CTRL c did give me the ability to type a new command. So I wonder if the first drive I started to preclear was canceled.

 

The second drive is still going. Is there a way to check?

 

Thanks!

Did you actually start 'screen'? It has to be installed and then started by running 'screen' before you can switch to a different screen. It is not actually part of unRAID so no it hasn't changed in this version of unRAID.

 

Tapatalk from CM10.1 Kindle

 

I must have missed that part. Pressing CTRL c did give me the ability to type a new command. So I wonder if the first drive I started to preclear was canceled.

 

The second drive is still going. Is there a way to check?

 

Thanks!

 

Ctrl+C is the standard unix command to abort the current task so if you had a preclear running in a normal terminal session that would kill it.

Did you actually start 'screen'? It has to be installed and then started by running 'screen' before you can switch to a different screen. It is not actually part of unRAID so no it hasn't changed in this version of unRAID.

 

Tapatalk from CM10.1 Kindle

 

I must have missed that part. Pressing CTRL c did give me the ability to type a new command. So I wonder if the first drive I started to preclear was canceled.

 

The second drive is still going. Is there a way to check?

 

Thanks!

 

Ctrl+C is the standard unix command to abort the current task so if you had a preclear running in a normal terminal session that would kill it.

 

That would explain it. Damn! I guess I have to wait even longer to get these drives precleared! 

 

Thanks for the help!

Just to be sure you're using Screen correctly, I'd Telnet in to UnRAID; start Screen; do a mundane command (Dir);  then switch to another screen session and perhaps do another mundane command of a different folder or disk -- then toggle between the screens to confirm you've got this "down pat".

 

THEN you can use the same process to start multiple Pre-Clear operations.

 

You do, however, at this point, need to wait for the current pre-clear to complete 

Apparently others who've had this issue could use the normal UnRAID "clear" function by disabling Simple Features.

 

Were you using Simple Features?