What is Unraid and how to build an Unraid media server

[Jamie]

Thanks

[Jamie]

Here is a video describing the case Paul suggested earlier in this thread.

https://www.youtube.com/watch?time_cont ... MBY1_bMhc8

Here is Part 2 which I added after Pauls response.

https://www.youtube.com/watch?v=PCects7grAs

Note: There is some installation for the case. For the 2 - 2 1/2 inch drives internal bracket, they supply the materials (screws and bracket) but you have to put it together. Also for the Motherboard posts, you have to screw the posts in the bottom of the case. They supply the posts and screws.

Jamie

[Jamie]

Okay, I was wrong. The bracket for the 2 - 2 1/2" drives is installed on the case wall.

Paul, I am a little confused concerning what the extra brackets shown in the 2 attached photos are used for and whether the removed screw in one picture is the posts for the Motherboard?

20190319_184336_2.jpg (216.96 KiB) Viewed 10958 times

20190319_184757_3.jpg (248.5 KiB) Viewed 10958 times

[Pauven]

Here is a video describing the case Paul suggested earlier in this thread.

https://www.youtube.com/watch?time_cont ... MBY1_bMhc8

Note: There is some installation for the case. For the 2 - 2 1/2 inch drives internal bracket, they supply the materials (screws and bracket) but you have to put it together. Also for the Motherboard posts, you have to screw the posts in the bottom of the case. They supply the posts and screws.

Jamie

I watched the video, plus the part II video, and he shows something that you should NOT do:

image.png (489.38 KiB) Viewed 10954 times

Notice how he runs the SAS cables over the fan divider, do NOT do this. There should be a gasket on the top panel that aligns with this divider, and it forces all air to pull through the front drives, through the fans, and out the back. If you run the cables over the top, you will interfere with the gasket, and your air flow will short-circuit, reducing your cooling performance.

Notice in the picture that there are cable passthroughs at the far left and right side of the fan divider frame. Run all cables through these.

I've build so many PC's over the years, I don't even think about the standoffs anymore. It's pretty standard that you have to install those, and do so to align to your particular motherboard. It's actually a bad practice that some cases come with pre-installed standoffs, and if you aren't careful there could be an extra one that doesn't align with a motherboard hole and instead short circuits your motherboard! At least when you start from scratch, you have to pay attention to every last post.

Paul

[Pauven]

Okay, I was wrong. The bracket for the 2 - 2 1/2" drives is installed on the case wall.

Paul, I am a little confused concerning what the extra brackets shown in the 2 attached photos are used for and whether the removed screw in one picture is the posts for the Motherboard?

At least one of those brackets should be for the power supply. The case comes pre-installed for an ATX power supply (which is what you should have bought). There are also server type power supplies, in single or dual (redundant) configuration. I think two of the brackets are for different power supplies.

That third bracket does look like a drive tray. As I recall, there may be a spot for an extra internal drive on the other wall near the power supply. Perhaps that is it?

Yes, the removed screw is a motherboard post.

Paul

[Jamie]

Yes, I bought the ATX power supply you recommended earlier. Thanks for your help.

[Jamie]

Hi Paul,

One last question.

When I replace a drive in my Drobos either by swapping out a drive for a larger drive, or due to a drive being reported as a bad drive, the Drobo automatically rebuilds the array.

What do you do when you replace a drive in an unraid server? Do you have to manually invoke a parity check, or another task, in order to move the data from the replaced drive to the new drive?

Jamie

[Pauven]

In Unraid, the process is very similar but slightly different - it requires some manual intervention. At a very high-level, the process is this:

1. In the GUI: Stop the Array (this allows you to edit it / make changes)
2. Replace the old drive with the new drive
3. In the GUI: Assign the new drive to replace the old one
4. In the GUI: Check the box to confirm the rebuild and Start the Array
5. The rebuild will take about 10-30 hrs, during which time read/write performance will be lower.

While you can use your array normally during the rebuild, out of an abundance of caution I typically try to avoid writes to the array during a rebuild. I don't go to any great lengths, for example if My Movies wants to update meta-data then I let it do its thing, but I do avoid ripping new movies during a rebuild as I feel that's just a very stressful event.

The steps listed above ignore the Pre-Clearing steps, which are highly recommended for any and all drives you add to your array, new or replacements. So here is a slightly expanded list of steps to include the Pre-Clear:

1. Insert the new drive into a spare bay
2. Pre-clear the drive (usually takes 2-3 days)
3. Review the Pre-clear stats to make sure you're happy with the new drive
4. Remove the new drive
5. in the GUI: Stop the Array (this allows you to edit it / make changes)
6. Replace the old drive with the new drive you pre-cleared
7. In the GUI: Assign the new drive to replace the old one
8. In the GUI: Check the box to confirm the rebuild and Start the Array
9. The rebuild will take about 10-30 hrs, during which time read/write performance will be lower.

While the Pre-Clear writes 0's to the entire drive, and writes the Unraid Cleared signature to the drive, both of these are ignored when you are replacing a drive, since the rebuild will once again write to the entire drive the contents of the old drive, plus 0's to fill up any extra space on the new drive, and write a new Unraid signature. So a lot of the benefit of a Pre-Clear is lost when you are replacing a drive, but there is still one major benefit to be realized: The Pre-Clear gives the new drive a workout before you add it to your system, and can alert you to a pending failure even on a brand new drive. For this reason, I still recommend a Pre-Clear even for drive replacements.

Paul

[Pauven]

The drobos used some of the disk space on each drive as overhead and also only 80% of the drives could be used. Do I have to be concerned with overhead on unraid, or can I figure that most of the drive space will be used except for that last 100 GB as you mention in an earlier post?

You really shouldn't have to be concerned about overhead with Unraid. You can even use most of that last 100 GB, I just wouldn't use it through a Share to copy really big ISO's. Essentially, you should be able to easily utilize 99.9% of every data drive. Your two parity drives are the only sacrificed capacity.

I know it has been a while, but I wanted to follow up on this post with an update. Last week I noticed that almost all of my drives had dropped below 100GB free, and that I was essentially writing all new rips to Disk 19. The space available on most disks was in the 80-100 GB range, per my share restrictions. I also had several boxes of DVD's that I'd yet to rip in storage, and thought it was finally time to rip them and fill up the nooks and crannies of my left over disk space.

It's been a 5 day ripping marathon, and I'm down to the last handful of DVD's, but the results speak for themselves. I first ripped some large 4K UHD's or Blu-rays directly to a disk to take up the bulk of the space, then filled in whatever remained with DVD's. It was a methodical process, and I used a spreadsheet to record the size of various DVD's before ripping, and made decisions on which drives to write to before ripping.

image.png (881.32 KiB) Viewed 10718 times

Notice that disks 2-18 are all at or below 3 GB free, and add those up and you barely reach 20 GB of total free space across those 17 drives.

I'm leaving extra space on Disk 1 for my music collection that lives there. Disk 19 is where new rips are currently writing. And Disk 20 is reserved for my various home PC backups.

My goal was to leave 1-3 GB free per disk, though I wasn't afraid to drop below 1GB. I really didn't want to drop below 500 MB, though as you can see for disk 2 I did some bad math and got down to 287 MB. I don't want to go any lower than that, as I like to leave room for metadata and I like to have a safety buffer so I don't run out of disk space.

And everything works fine.

At the bottom of the image you can see I have a couple 'Unassigned Devices', a pair of 8 TB drives that I've already pre-cleared. Once I finish filling up Disk 19, I will swap those drives in to replace a couple 3 TB drives and get a nice 10 TB space upgrade.

After the space is upgraded, I'll take the 3TB drives that I pulled and pre-clear them again, and keep them as emergency spares in case of a drive failure.

[Jamie]

Thanks for following up Paul. It's good to hear that you can use up all that disk space!

Jamie