Right now I have a Buffalo terastation and some netgear Readynas so I am trying to learn about Unraid for the first time. 

 

I'm going to ask you a bunch of questions and I want to have them answered immediately( Arnold voice) 

 

https://www.youtube.com/watch?v=w3sLzmmejCA

 

 

1. Can you have more than 1 Parity disk?  If I have a 30 drive configuration, there is more chance more than 1 drive might fail then if I have a 4 drive raid system(like I have now) 

2. If 2 or more drives fail, is the entire array lost or is the individual data on the disk still good. This is a combination of a JBOD with a parity so you kind of gets the best of both worlds on a JBOD and RAID. 

3. If the hard drives which are not in use spin down to save power, how does the unraid know if a drive as failed? Does it have some kind of test cycle it can run to make sure all the drives are working of know if a drive has failed? 

4. Is unraid the same software that the Drobo runs? I think the Drobo also can run different drive sizes. 

5. Can externals drives be part of the protected array or do you have to remove them from their enclosure and connected them to the motherboard via SATA cable? 

6. Should the parity disk be the more reliable drive in your array? Like WD black edition or something design for serious use? Does the parity drive need to be the largest drive in the array? 

7. The negative about unraid is the writing speed but not the read speed? 

8. Is unraid the operating system or a software that runs in windows/linux? 

9. Can you start out small and keep adding new drives to the system right?  

 

Thanks. 

Edited May 1, 20179 yr by miogpsrocks

If you want answers to most of your questions immediately I suggest you read the FAQ

Which has a good many of the answers already in one place.

 

In short:

1) yes

2) rest of data are still good

3) perform routine parity checks to exercise all drives and have the system report SMART errors as it goes

4) no

5) yes

6) doesn't matter. I personally prefer 5 year warranty drives so i don't have to replace them as often

7) There are ways around all speed issues, but most folks don't want to shell out for 60TB SSDs to get high speed unRAID writes

8. unRAID is a linux-based OS

9) Yes - that's a primary advantage of unRAID versus other RAID array solutions

1 hour ago, miogpsrocks said:

Should the parity disk be the more reliable drive in your array?

Here's the thing.  If a disk fails, unRAID allows you to replace it without data loss.  It does so by using the parity drive... plus all the other drives in your array.  Everything has to spin up in order to emulate the failed disk.  So all your drives need to be reliable.  I like WD Reds.  Oh, and by the way - unRAID (and for that matter any form of RAID) isn't a backup solution by itself.

 

 

1 hour ago, miogpsrocks said:

The negative about unraid is the writing speed but not the read speed?

Read up on Turbo Write, linked in my signature.  If write speeds to the parity protected array are a concern, Turbo Write is a great solution - with the caveat that it spins up all the drives.

Edited May 1, 20179 yr by tdallen

1 hour ago, miogpsrocks said:

6.  Does the parity drive need to be the largest drive in the array? 

Yes, both parity drives must be large than any data disk in the array.  Either parity drive can also can also be larger than the largest data disk (or the other parity disk for that matter).    Look here for information on how parity is implemented in unRAID:

 

http://lime-technology.com/wiki/index.php/UnRAID_Manual_6#Parity-Protected_Array

1 hour ago, bman said:

If you want answers to most of your questions immediately I suggest you read the FAQ

Which has a good many of the answers already in one place.

 

In short:

1) yes

2) rest of data are still good

3) perform routine parity checks to exercise all drives and have the system report SMART errors as it goes

4) no

5) yes

6) doesn't matter. I personally prefer 5 year warranty drives so i don't have to replace them as often

7) There are ways around all speed issues, but most folks don't want to shell out for 60TB SSDs to get high speed unRAID writes

8. unRAID is a linux-based OS

9) Yes - that's a primary advantage of unRAID versus other RAID array solutions

 

 

 

Thank you for answering all my question so quickly. I'm not sure if you saw the link but it was kind of a joke statement from a movie.  I was not trying to be really demanding or anything. 

 

Anyway, why would you need "60TB SSDs to get high-speed unRAID writes", could you just deal with like a 240 GB SSD if you were not planning on transferring that many files? 

 

I may be adding some 4K drone footage that is a few GB at a time not transferring anything every that a 240 GB would not handle. Is the 60TB in SSD  just a random example or is there some reason the SSD cache array would need to be that big? 

 

Thanks. 

 

 

 

10 minutes ago, miogpsrocks said:

I'm not sure if you saw the link but it was kind of a joke statement from a movie.

6 minutes ago, miogpsrocks said:

Is the 60TB in SSD  just a random example or is there some reason the SSD cache array would need to be that big? 

This was also a joke. 60TB is larger than readily available (or even unavailable?) HDDs much less SSDs. There was a recent thread that talked about these cutting edge, "unobtainium" drives and how expensive they were

 

Cache needs to be large enough for any apps (dockers, VMs) you want to live there (for performance), plus the amount of cached writes you will make between scheduled moves (schedule can be set). Some people don't cache writes, or not much. Most of the writes to my server aren't cached since they are unattended. Mostly queued downloads or scheduled backups, so I don't sit around waiting for them to complete anyway.

 

Each user share has a setting that controls whether and how it uses cache. The default is to not use cache.

19 minutes ago, trurl said:

This was also a joke. 60TB is larger than readily available (or even unavailable?) HDDs much less SSDs. There was a recent thread that talked about these cutting edge, "unobtainium" drives and how expensive they were

 

Cache needs to be large enough for any apps (dockers, VMs) you want to live there (for performance), plus the amount of cached writes you will make between scheduled moves (schedule can be set). Some people don't cache writes, or not much. Most of the writes to my server aren't cached since they are unattended. Mostly queued downloads or scheduled backups, so I don't sit around waiting for them to complete anyway.

 

Each user share has a setting that controls whether and how it uses cache. The default is to not use cache.

 

5

 

5

 

I think they do have a 60TB SSD but I was not sure if you were talking about this or some kind of array made up of smaller SSD drives to equal 60TB

 

https://arstechnica.com/gadgets/2016/08/seagate-unveils-60tb-ssd-the-worlds-largest-hard-drive/

 

 

I do have a 120GB SD laying around the house not used. What is the hard in throwing that in the system? I can even use velcro tape to mount it on the case somewhere. 

I really need the space for data storage mostly video files. These are not really needed for reading data right? Its just like a waiting room since the parity process takes so long to calculate and complete? 

 

Thanks.  

Edited May 1, 20179 yr by miogpsrocks

If you use Turbo write (as I do), you will get write speeds that about about 2/3 of what you might get with a cache.  (without Turbo Write that will drop to about 1/3 of the read speed.)   If you intend on using unRIAD for either a Media storage or long term data archiving, you will probably be doing more reading than writing anyway (once you get the initial data transferred).  I can store a 25GB BluRay iso on either of my servers in about 5.5 minutes using turbo write.  Now storage of a the data from my Windows computer (~10GB, 4000+files)  will take about 11-12 minutes because the file handling overhead.  Remember that even with a cache drive, you won't get rid of that file overhead time. 

 

As @trurl said, the cache drive is where you want to put your Dockers and VM's.  A ssd is the ideal environment for that usage! 

 

EDIT:  Remember that the data transfer speed is usually limited by the network and that will max out 120MB/s and most of the time it will be closer to 100MB/s. 

Edited May 1, 20179 yr by Frank1940

 

10 minutes ago, Frank1940 said:

If you use Turbo write (as I do), you will get write speeds that about about 2/3 of what you might get with a cache.  (without Turbo Write that will drop to about 1/3 of the read speed.)   If you intend on using unRIAD for either a Media storage or long term data archiving, you will probably be doing more reading than writing anyway (once you get the initial data transferred).  I can store a 25GB BluRay iso on either of my servers in about 5.5 minutes using turbo write.  Now storage of a the data from my Windows computer (~10GB, 4000+files)  will take about 11-12 minutes because the file handling overhead.  Remember that even with a cache drive, you won't get rid of that file overhead time. 

 

As @trurl said, the cache drive is where you want to put your Dockers and VM's.  A ssd is the ideal environment for that usage! 

 

EDIT:  Remember that the data transfer speed is usually limited by the network and that will max out 120MB/s and most of the time it will be closer to 100MB/s. 

6

 

 

 

What type of " Dockers/VM" do most people run on these? Like Plex to stream video files or like BlueIris or some kind of security camera DVR softrware? 

 

I was thinking this was just some network storage but if I can run some computer app on it, that is icing on the cake. 

 

 

Edited May 1, 20179 yr by miogpsrocks

3 minutes ago, miogpsrocks said:

What type of " Dockers/VM" do most people run on these? Like Plex to stream video files or like BlueIris or some kind of security camera DVR softrware? 

There are literally hundreds of dockers supported by members of the unRAID forum.

 

https://rawgit.com/Squidly271/AppsThread/master/forumpost0.html

 

Install the Community Applications plugin to find and manage them.

 

5 minutes ago, miogpsrocks said:

What type of " Dockers/VM" do most people run on these? Like Plex to stream video files or like BlueIris or some kind of security camera DVR softrware? 

 

 

I just looked on the Community Applications plugin and there are currently 401 applications available.  They cover about anything that you might want to do.

 

VM's are a category unto themselves.  That are several folks who have actually setup a Windows 10 gaming rigs with high end video cards being passed through.  I seem to recall that several folks have setup VM's to handle more mundane tasks like compiling programs which don't require as much hardware or resources.  It is pretty much up to you what you try to so with unRAID.  Oh, you would have to have some high-end hardware to do some of it...   

On 2017-05-01 at 3:53 PM, miogpsrocks said:

 

Anyway, why would you need "60TB SSDs to get high-speed unRAID writes", could you just deal with like a 240 GB SSD if you were not planning on transferring that many files? 

 

 

 

 

 

You can use traditional RAID types to get more read or write speed than a single HDD (or SSD) can provide.  unRAID offers no such advantage here, except in the case of cache, which isn't the same as the regular data array.  I was merely pointing out that you can get around your mentioned "negative" regarding write speeds and compete with traditional RAID configurations if you really want/need to.

 

The 60TB SSD is so far unobtainable, but is reality, and if you get in line you can probably have one sometime this year if you've got loads of cash to part with. You would of course want at least two of them so you could have parity protection, but why stop there?

42 minutes ago, bman said:

 

You can use traditional RAID types to get more read or write speed than a single HDD (or SSD) can provide.  unRAID offers no such advantage here, except in the case of cache, which isn't the same as the regular data array.  I was merely pointing out that you can get around your mentioned "negative" regarding write speeds and compete with traditional RAID configurations if you really want/need to.

 

The 60TB SSD is so far unobtainable, but is reality, and if you get in line you can probably have one sometime this year if you've got loads of cash to part with. You would of course want at least two of them so you could have parity protection, but why stop there?

 

How bad is the write speed without the cache or turbo write?

I get write speeds of about 25MB/s on my oldest, slowest unRAID server, and about 65MB/s on the newest without any tweaking or cache use.

31 minutes ago, miogpsrocks said:

How bad is the write speed without the cache or turbo write?

Roughly half of the Turbo speed.  (I can't comment on the parity vs read/modify/write as I have never had a cache drive installed on either of my systems.)  But the actual write speed in all cases is dependent on the size of the files being written.  There is the overhead from file creation on the file system and getting the allocation of disk space for each file which is a negative on write speeds.  I have seen the write speed for a large batch of small data files ( like small MSWord files) drop the average write speed in half compared to a BluRay iso file on both read/modify/write and reconstruct write.  I am not sure that you would see a similar discrepancy in writing to a cache drive.   One other factor is that an ssd cache drive will be much faster than a HD because it will eliminate the mechanical time that the HD requires to move the head to the right track and for the disk to get the data under the head for the read/write operations. 

 

EDIT:  One more quick comment.  Double the write speed so the time drops from 10 mins to 5 mins is a savings of 5 mins.  Doubleing it again will only be a saving of 2.5 mins.  The law of diminishing returns applies here... 

Edited May 3, 20179 yr by Frank1940