New Unraid System with Old Drives

[phileeny]

The Current Unraid server is a 24 bay rack mount that is nearly full of drives, so any new drives fitted will be a replacement of the older smaller drives.

 

Having stripped some computers of their hard drives and collected old drives over the years I now have 13 standard HDDs from two SATA III 3TB WD green down to one SATA I 250GB Maxtor.

 

I want to continue to use these drives and any drives taken from the main server in time, now all these drives are non-NAS drives and I know one or two that did fail in the main server with "Device contents emulated" or "Device is disabled, contents emulated" errors as more drives were installed in the main server over time, probably due to vibration, a few of these drives are now in a windows system and despite their age are still working, slow but working.

 

Problem with Windows is a drive dies data lost, Storage Spaces (yuck and don't trust it)

 

I will be re-build the Windows system in to an new Unraid system using the 3TB green or the 3TB Samsung as Parity drives and the other old drives as data, this new system "where my drives will go to die with dignity" will not be running all the time but only turned on when needed, the drives will be stored with rubber anti-vibration grommets in a Li-Lan PC8000 case.

Do you think this will work or will the drives keep giving "Device is disabled" error, I guess even if it does error data still not lost.

Edited June 8, 2020 by phileeny

[Frank1940]

I would like to (respectfully) suggest that you reread your first post.  Then edit it so that anyone can understand exactly what you did and what you are trying to do.  (I suspect that the resulting edit/(rewite) will be two to three times longer than your original post.)

[Jessie]

1 hour ago, phileeny said:

The Current Unraid server is a 24 bay rack mount nearly full of drives so the drives will be replaced with bigger in time.

Having stripped some computers of hard drives and collected others over the years I now have 13 standard HDDs from two SATA III 3TB WD green down to one SATA I 250GB Maxtor.

I want to continue to use these drives and the old drives taken out of the main server in time, now all these drives are non NAS and I know one or two that did fail with 

"Device contents emulated" or "Device is disabled, contents emulated" error in the main server as more drives were installed over time, probably due to vibration, a few of these drives are now in a windows system and despite their age are still working, slow but working.

Problem with Windows is a drive dies data lost, Storage Spaces (yuck and don't trust it) so I want to rebuild the Windows system in to an new Unraid system using the 3TB green or the 3TB Samsung as Parity drives, this new system where my drives will go to die with dignity will not be running all the time but only turned on when needed, the drives will be stored with rubber anti-vibration grommets in a Li-Lan PC8000 case.

Do you think this will work or will the drives keep giving "Device is disabled" error, I guess even if it does error data still not lost.

If a drive fails, you lose your array protection.  I reckon I would weed out the sus drives.  Move data onto the good drives and reconfigure the array so it is reliable.  If the motherboard can handle iommu passthrough, put a windows vm onto it and pass the graphics onto a gpu. Then you are running a system with your data protected.  Windows will run faster on Ssd's .  A couple of ssds for cache and run windows on that.  There should be extra space on the cache for the rest of unraid.  eg use a pair of 500gb ssds for the array then use 200gb for a windows vm and use a share on the array for bulk data. The rest of the ssd will handle data transfer to the array.  I don't think hard drive types matter that much, although standard drives might run hotter, so cooling matters.

[phileeny]

35 minutes ago, Jessie said:

If a drive fails, you lose your array protection

Only if a parity drive fails sure, but if the Parity is ok the data is ok, the Unraid system I will build will just be for data there will be no need for VM's and there are no SSD's

The Idea is to just use the old drives and ones taken out of the main server, like a "hand-me-downs" system.

[Jessie]

26 minutes ago, phileeny said:

Only if a parity drive fails sure, but if the Parity is ok the data is ok, the Unraid system I will build will just be for data there will be no need for VM's and there are no SSD's

The Idea is to just use the old drives and ones taken out of the main server, like a "hand-me-downs" system.

If you are relying on the parity drive to emulate the disk and you lose another disk, data gone.  If you are using 2 parity disks, you can afford to lose 2 disks.  After that, data loss.  In the end for system integrity, you really want to repair the array otherwise, they are running as single disks.

 

To further explain. On a 1 parity disk system, you can only afford to lose one drive at a time.  So if parity fails, you replace and the array rebuilds it. If one of the array drives fails, the parity calculates the contents of the drive using the info stored on parity plus the checksum of the data on the other drives.  So if you lose 2 data drives, parity doesn't know how to calculate the contents of the first failed drive because it cant obtain a checksum from the second failed drive.  There is a good article on this on the website.

 

The plus side to this is the data is wholly intact on the remaining unfailed drives so you would only lose data on the failed drives.   By comparison, raid arrays which use striping, more than 1 failed drive there and you lose the lot.

 

(I keep adding to this)

One reason to have 2 parity disks is because if you have a system with a lot of disks, there is a possibility of a drive failure during a rebuild of a failed disk.  Mainly because the drives are going to be hammered for 6 hours or so during the rebuild.  It is possible some of those disks spend most of their time powered down, so its pending failure might not be immediately noticed.

 

Personally I don't worry about a second parity unless there are more than say 12 drives in the system.  I usually schedule a parity check once a month.

 

 

Edited June 8, 2020 by Jessie

[phileeny]

In Windows I'm currently moving the data from the five smallest and oldest drives to a 3TB drive.

That will then give me the following

Parity 3TB

Data 250GB + 300GB + 500GB + 500GB + 500GB

That will give me enough drives to start the build the "where my drives will go to die with dignity" server, I need a better name.

[Frank1940]

36 minutes ago, Jessie said:

One reason to have 2 parity disks is because if you have a system with a lot of disks, there is a possibility of a drive failure during a rebuild of a failed disk.  Mainly because the drives are going to be hammered for 6 hours or so during the rebuild.  It is possible some of those disks spend most of their time powered down, so its pending failure might not be immediately noticed.

This is a very primary reason for using dual parity.  Especially if you are planning on using drives which are already suspect.  With a 3TB parity array, you are looking at around 9 hours to rebuild a disk.  (And this time may be low if you have a mix of (slow) disks with small size.  i.e., that 250GB Maxtor.)   Remember, you have already stated that this is the place that you are sending HD's to die.  You may want them to die one at a time but you should really be planning for Mr. Murphy being in attendance!

[JonathanM]

46 minutes ago, phileeny said:

Only if a parity drive fails sure, but if the Parity is ok the data is ok, the Unraid system I will build will just be for data there will be no need for VM's and there are no SSD's

The Idea is to just use the old drives and ones taken out of the main server, like a "hand-me-downs" system.

@Jessie already addressed this, but it's important enough I need to add my emphasis.

 

Unraid uses ALL the drives for parity protection, not just the parity drive.

 

If 1 drive fails, all the other drives in the array must perform flawlessly from end to end to rebuild the failed drive, not just the parity drive.

 

You will be relying on your hand me down drives to protect the data. They must all be perfect. Even more so than a typical system, where the only spots on the drive that matter are the ones that actually contain data, unraid requires the entire capacity to be perfect across all remaining disks. You must weed out any weak or failing drives before using them in the parity protected array, and vigilantly replace any that start to fail, so you don't get in a situation where a failing drive causes a weak drive to fail in the middle of a rebuild of the failed drive.

 

https://wiki.unraid.net/Parity

[Frank1940]

5 minutes ago, phileeny said:

Parity 3TB

Data 250GB + 300GB + 500GB + 500GB + 500GB

In this case, the  Parity2 drive need only be 500GB.  (The rule is that any parity drive must equal or larger in capacity than the largest data drive.)

[phileeny]

It will be fun to find out how well or not it works, I also have five very old PATA (IDE) drives.

Seagate Barracuda 80GB

Seagate Barracuda 200GB

Maxtor 250GB ATA 133

Maxtor 250GB ATA 133

WD Blue 500GB

I would like to use them but I don't have way to connect them I've not seen any 5x IDE caddy.

[Frank1940]

7 minutes ago, phileeny said:

I would like to use them but I don't have way to connect them I've not seen any 5x IDE caddy.

If memory serves me correctly, the IDE (PATA) cable will only support two drives!  SATA usage has become virtually universal on new PC's since about 2008.  In fact, I can not recall seeing a PATA connector on any recent MB...

[phileeny]

One of my early media server builds had both IDE and SATA on the motherboard, that system had two Rom drives and two HDD's connected to both IDE, and a IDE controller connected to a PCI slot for four drives and the SATA I think had four drives.

My first ever SATA drive, I connected the data and power and moved the cable to cable manage and broke the data connection even before I turned the system on, no returns that hurt.

[Jessie]

7 hours ago, phileeny said:

It will be fun to find out how well or not it works, I also have five very old PATA (IDE) drives.

Seagate Barracuda 80GB

Seagate Barracuda 200GB

Maxtor 250GB ATA 133

Maxtor 250GB ATA 133

WD Blue 500GB

I would like to use them but I don't have way to connect them I've not seen any 5x IDE caddy.

IDE only allowed 2 drives per cable. Master and a slave. so you would need a motherboard with 3 ide controllers.  That would go back to the xp era or maybe early vista.  The processors would be 32 bit, so current unraid wouldn't run.  Maybe Unraid 4 or lower might go.  Personally, if you wanted to use those drives, try building a windows 95 machine. (for the museum)  It's harder than you think.  I built one up last year to get data from an old tape drive which would only work on win95.  Found an old 386 chassis, put a gig of ram and a 200gb hard disk.  No go. Had to reduce ram to under 500mb and use a drive smaller than 32gb.  Once I had the data, no usb support, so I had to find a later xp machine that supported ide and copied off the hard disk from that.  Your drives might work on win 98 or Windows NT (Remember NT?) Not sure about the 500. It might be too large.

Edited June 8, 2020 by Jessie

[phileeny]

Good idea Jessie.

I've got lots if bits so I could build an old system, I too had a tape drive Iomega Ditto with qic40 tapes i think, never did get that to work in later years, I couldn't remember what was on it and it got destroyed years ago.