[Solved] Pre-clearing a replacement drive with no free SATA ports.


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Hey folks,

I am out of space on the unRAID box so I picked up a 3TB Seagate NAS drive. I want to preclear it with Joe's script, but just want to enquire about the best / fastest method.

 

Here's the catch: I have all SATA ports used by my data drives. So, to preclear this new drive, I'd have to first remove one of the data drives and install this drive.

 

I'm thinking my best option will be to stop the array, shut down, swap the drives, then boot up and again stop the array... then run the preclear script on the new drive, then assign the new drive to the data slot where the old drive was, and then start the array.

 

This will mean my array will be offline for days. Is there a better way?

 

I do have a BlacX dock which I suppose I could connect via USB (remember, no more SATA ports) but that'd be unbelievably slow I'd think.

 

Thanks for your tips!

 

-- Update

See https://lime-technology.com/forum/index.php?topic=41547.msg395328#msg395328 for the final result.

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Don't know about that particular dock. Is it USB3? I think there is an issue with getting smart data with some (all?) USB docks.

 

Do you have another computer you could use? You could boot unRAID on another computer and preclear that way.

 

If you do decide to run it on your existing system, it might be better to boot unRAID from another flash drive so your existing system doesn't get confused with all the disk swapping.

 

Whether you do it on another system or your server, be very careful and make sure you select the correct disk to preclear. Maybe even disconnect all the other disks.

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Neah it's USB 2.0 or ESATA. Good note re. SMART, so that rules that out.

 

I have an old server laying around... I suppose I could create a flash drive with the unRAID trial... good thought!

 

I had already been thinking about converting that old girl into an unRAID box anyways (as it has a dual-processor XEON and a huge SATA backpane) so this would be a good chance to take it for a spin while keeping my main server online.

 

Why didn't I think of that?!  :)

 

Thanks so much,

Robbie

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Hey folks,

I am out of space on the unRAID box so I picked up a 3TB Seagate NAS drive. I want to preclear it with Joe's script, but just want to enquire about the best / fastest method.

 

Here's the catch: I have all SATA ports used by my data drives. So, to preclear this new drive, I'd have to first remove one of the data drives and install this drive.

 

I'm thinking my best option will be to stop the array, shut down, swap the drives, then boot up and again stop the array... then run the preclear script on the new drive, then assign the new drive to the data slot where the old drive was, and then start the array.

 

This will mean my array will be offline for days. Is there a better way?

 

I do have a BlacX dock which I suppose I could connect via USB (remember, no more SATA ports) but that'd be unbelievably slow I'd think.

 

Thanks for your tips!

 

if you're on unraid6, a gotcha is to make sure you have the latest version of the preclear script...

 

it will still run the preclear with older versions but unraid doesn't recognise it as precleared.

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If you have an eSATA port on your existing server, and a way to connect your disk to that port, that is a good option for preclearing. In an older server I ran an eSATA to SATA cable from outside the case to inside to enable me to have one more port. Same speed as any SATA port. Worked great.

 

But I prefer to preclear on a backup or alternate server so as to avoid any downtime on my main array. Setting up a makeshift preclearing machine is very easy. I actually have an old HTPC that I don't use any more and pulled it into preclear duty once or twice.

 

Good luck!

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Yeah bjp999 I really like the idea of doing it on a separate box. Nope, no SATA ports at all are free (including eSATA)... my rig is chock full. Even the PCIe ports are all full of controllers.  LOL. My only option would be an SATA multiplier.  :)

 

I'll give it a go on the old box and see what comes of it. Being that it's a dual-cpu Xeon 3.2 with 8 cores, it may actually be really good for it! And nice that I don't have to take my main array offline.

 

Cheers!

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Hello, Everyone

 

Here is my takeaway from this thread.  if you don't want to do a Pre-clear on your poduction software you can do the following:

 

Download an evaluation copy of uNraid.

 

1.  Configure a flash drive with it.

2.  Boot that flash drive on an older machine.

3.  Configure and install Pre-clear (script and maybe Plugin).

4.  Connect the new hard drive by USB (2.x or 3.x) or eSata.

5.  Run the pre-clear script.

6.  Place the pre-cleared drive into the array and add it.

 

Does that sound right?  I am thinking that for a 5tb drive (which is what I have) I would be risking some crazy downtime if I pre-clear it in my live array.

 

Thank You

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Not evaluation copy - trial version. I don't think you'd have to actually get a license since you won't be defining and staying Ann array. You would want to install screen via Nerdpack or packages. Not sure if plugin works with array not started. If it does you may not need screen.

 

You do not want to Preclear with usb2, will take forever. Also, usb2 or usb3 may slightly mess with drive size, and preclear signature may not be properly recognized when connected via SATA. I would recommend therefore recommend only a SATA or eSATA port for preclearing.

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Not evaluation copy - trial version. I don't think you'd have to actually get a license since you won't be defining and starting an array. You would want to install screen via Nerdpack or packages. Not sure if plugin works with array not started. If it does you may not need screen.

 

You do not want to Preclear with usb2, will take forever. Also, usb2 or usb3 may slightly mess with drive size, and preclear signature may not be properly recognized when connected via SATA. I would recommend therefore only a SATA or eSATA port for preclearing.

 

I've done this a few times as well where I would load up unRAID on a spare machine and due a pre-clear that way. Just thinking out loud but it would be nice to avoid having to load up unRAID each time we do this. Something like having a live preclear USB stick you can load up on any computer real quick.

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I am thinking that for a 5tb drive (which is what I have) I would be risking some crazy downtime if I pre-clear it in my live array.
You can use the array just fine while preclear is running. The reason we are discussing a separate system is that the OP is out of SATA ports with no other good options. As long as you have a physical slot to install that 5TB drive without removing one of your array drives, you are good to go with just powering down the array, physically install the drive, start the array back up, then use the preclear script either with screen or the GUI plugin and use the array exactly as you do now while the preclear completes. After the preclear is done, stop the array, assign the drive, start the array, format the drive. VERY little actual downtime.

 

Since the OP is replacing a drive instead of adding a slot, preclear isn't technically needed, but I believe the intent is to use the preclear session to thoroughly test the drive before trusting it with data.

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Correct, yes: the intention behind the preclear is that I want to make sure the drive can be trusted while it's new (eg., easy to replace under warranty if it has trouble)... after all, we're into a 3TB drive here... a lot of data to recover via Parity if it were to fail... I'd rather have that peace of mind.

 

To further the discussion, I decided against USB because 1) it is too slow and 2) it was said that it may have trouble with SMART (which is a big part of why we're pre-clearing!).

 

I will be temporarily repurposing an old server to do the pre-clear, this way I don't have to take my array offline until the time I'm actually ready to swap drives... and since the drive will be pre-cleared, it won't be down for much time at all.

 

Also, regarding Screen... that's an extra unneeded step since I can plug a monitor and keyboard into the server (not use telnet). Only reason you'd need to do telnet / screen is if you don't have physical access to the server or wanna do it from a remote location (or other room).

 

Did you want me to film the process to feature on the show?

 

Thanks everyone!!

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Ah poo!
Bless you!!!

The SATA controller on the old server only supports drives <= 2 TB.
Not saying you are wrong about support, but if the only evidence you have is improper display when it detects the drive, that may not preclude its use. Does the syslog show the full capacity? Does preclear show 3TB? Some controllers have broken BIOS that improperly display, but the linux driver can use the full size just fine.
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Not saying you are wrong about support, but if the only evidence you have is improper display when it detects the drive, that may not preclude its use. Does the syslog show the full capacity? Does preclear show 3TB? Some controllers have broken BIOS that improperly display, but the linux driver can use the full size just fine.

 

It's a good thing you're not saying I'm wrong because then you'd be wrong!  :)  hehe

 

http://www.intel.com/support/chipsets/imsm/sb/CS-022304.htm

 

This ol' board falls under the 632xESB column  :)

 

All I need to do is pickup a SATA card and I'll be flying.

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Not saying you are wrong about support, but if the only evidence you have is improper display when it detects the drive, that may not preclude its use. Does the syslog show the full capacity? Does preclear show 3TB? Some controllers have broken BIOS that improperly display, but the linux driver can use the full size just fine.

 

It's a good thing you're not saying I'm wrong because then you'd be wrong!  :)  hehe

 

http://www.intel.com/support/chipsets/imsm/sb/CS-022304.htm

 

This ol' board falls under the 632xESB column  :)

 

All I need to do is pickup a SATA card and I'll be flying.

 

I did a pretty extensive test of motherboards and add on cards and found only one that did NOT support 2.2T+ drives, and that was the BR10i controller. So whatever you find has a good chance of supporting large disks.

 

I did not test the motherboard / chipset you are referencing here.

 

 

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Hello.  Thanks for the post.  I didn't see it at the time, but got the Pre-clear going and was able to continue accessing the array as you described.  When I left for work this Morning it was doing the Zeroing out portion.  I used the Gui.

 

I still like the idea of using a pre-clearing method seperate from the uNRAID server (as I don't always like to leave it on for serious lengths of time).

 

Thanks again...

 

I am thinking that for a 5tb drive (which is what I have) I would be risking some crazy downtime if I pre-clear it in my live array.
You can use the array just fine while preclear is running. The reason we are discussing a separate system is that the OP is out of SATA ports with no other good options. As long as you have a physical slot to install that 5TB drive without removing one of your array drives, you are good to go with just powering down the array, physically install the drive, start the array back up, then use the preclear script either with screen or the GUI plugin and use the array exactly as you do now while the preclear completes. After the preclear is done, stop the array, assign the drive, start the array, format the drive. VERY little actual downtime.

 

Since the OP is replacing a drive instead of adding a slot, preclear isn't technically needed, but I believe the intent is to use the preclear session to thoroughly test the drive before trusting it with data.

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Thanks for the clarifications.  I would have been doing USB3 if I could have.

 

Not evaluation copy - trial version. I don't think you'd have to actually get a license since you won't be defining and staying Ann array. You would want to install screen via Nerdpack or packages. Not sure if plugin works with array not started. If it does you may not need screen.

 

You do not want to Preclear with usb2, will take forever. Also, usb2 or usb3 may slightly mess with drive size, and preclear signature may not be properly recognized when connected via SATA. I would recommend therefore recommend only a SATA or eSATA port for preclearing.

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Just a brief update for ya's. Yes, the mobo I have in this old server only supports up to 2 TB as per the specs in the link I provided. It's a chipset limitation. So, today at work I asked the boss if we had any old SATA controllers hanging around and he found me one... a 6-port SATA I card!  LOL. So... slow as a dog, but thankful it DOES work -- it picked up the 3 TB drive no problem.

 

So I booted up the server from a flash drive with the latest unRAID Trial (6.0.1) and Joe's latest version of the preclear_disk.sh script from the forum, and immediately started pre-clearing the drive. It's the only drive in the box so no worries about finding the right one  :)

 

It's chugging along right now at about 83 MB/sec doing the pre-read, so it's certainly moving at an acceptable pace despite the old SATA controller. And since it's a separate box and my unRAID server (think: PLEX) are still online for the weekend, so I'm happy!  Once it's done the pre-clear, I'll simply remove one of my 500 GB drives and replace it with the 3 TB drive.

 

A note for n00bs... I have a couple 400 GB drives and a couple 500 GB drives. Note that I am replacing a 500 GB drive. The temptation might be to replace a 400 GB drive since a 500 GB drive will give me an extra 100 GB if I leave it in the array. Here's my reasoning: If I replace one of the two 400 GB drives, I will then have a 400 GB drive as a spare. If the other 400 GB drive fails, I can replace it. However, if any other drive in the array fails, I will have to buy a new drive. By replacing one of the 2 500 GB drives, I now have a 500 GB spare. That means if the other 500 GB drive OR either of the 400 GB drives fail, I have a spare on hand. My likelihood of having to buy new gear in event of drive failure was just cut by 2/3 and the only expense to me is 100 GB of storage (which is moot since I'm adding 2.5 TB).

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... A note for n00bs... I have a couple 400 GB drives and a couple 500 GB drives. Note that I am replacing a 500 GB drive. The temptation might be to replace a 400 GB drive since a 500 GB drive will give me an extra 100 GB if I leave it in the array. Here's my reasoning: If I replace one of the two 400 GB drives, I will then have a 400 GB drive as a spare. If the other 400 GB drive fails, I can replace it. However, if any other drive in the array fails, I will have to buy a new drive. By replacing one of the 2 500 GB drives, I now have a 500 GB spare. That means if the other 500 GB drive OR either of the 400 GB drives fail, I have a spare on hand. My likelihood of having to buy new gear in event of drive failure was just cut by 2/3 and the only expense to me is 100 GB of storage (which is moot since I'm adding 2.5 TB).

 

A n00b Q&A ;)

 

Why don't you move the data off of your 400/500GB disks to the new 3TB disk, reducing the likelyhood of multiple disk failure (and freeing up SATA ports in the process)? Having another 3TB disk as spare may be an option as future investment...

 

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bonienl yes, I could definitely do that, but I really want to maximize the space. And to be 100% clear, I have a full backup of all the important stuff on the array, off-site. So the problem of multi-drive failure is more of a time thing than a data loss thing for me. Yeah, I suppose I could indeed consider what you suggest, and it's a really good suggestion... deprecate those old 400-500 GB disks and maybe add yet another 3 TB in one of their place, reducing the power consumption of the rig, the chance of multi-drive failure and so-on...

 

But that said, there is some truth in this: a 3TB drive is more likely to catastrophically fail and lose data than an old 400 GB drive  :)  The old saying rings true: they don't build 'em like they used to - haha!

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Upgrade complete. Thanks for the initial suggestions folks. I replaced the 500 GB drive with the pre-cleared 3TB drive, having pre-cleared it on the old server I had laying around. It took around 46 hours to pre-clear, but my array was up during that time since I didn't do it on the unRAID box.

 

The only other note is that I ran a parity check beforehand. I wanted to know I had 0 parity errors before swapping drives. With 0 errors, I was fully confident in pulling that 500 GB and it went great. unRAID was only down for about 10 minutes while it came online with the new drive, then it proceeded to restore the data to the 3TB drive for me while everything was up. During that process, we watched a 720p movie on Plex without a single skip, so I was pleased  :)

 

Thanks again!

Robbie

 

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I always do a parity check before a drive upgrade. Before even doing the parity check I will look at / save the smart reports and after the parity check look at them and compare with the before values. If I don't see any issues I feel very safe doing the rebuild.

 

Glad all went smoothly and now you have 2.5G to grow!

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Glad all went smoothly and now you have 2.5G to grow!
Heh. I use 2.5GB for half a movie.  ;D

 

Ain't it a bitch being so old that a MB seems big and a GB is huge and a TB is unfathomable? Speaking of RAM in GB and storage in TB is quite a contrast to 256K SIPPs and 20MB full height HDDs.

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