Hi, I am currently reading up massively on this using the wiki etc. I have looked into this before but really need to build a server now. I have been looking at flexraid as a competitor but do not like the lack of support it gets. Can someone fill me in on the below questions please?

 

1: There is a limit with unraid as to the amount of drives that can be used. Why? What possible benefit does this have for the creators of unraid to limit users in this way?

 

2: Can one upgrade the storage inside an unraid array so that if an array was using 10 x 2TB drives, they could swap to using 10 x 3TB drives? i.e. Can you expand the array on the fly without rebuilding from scratch then getting rid of the older smaller disks? If so, then question 1 above isn't so much of an issue. If not, is this going to become a feature?

 

3: How difficult is it to bundle on extra duties to the OS like torrent and backup clients?

 

4: Is it possible to run XBMC client on an unraid box in addition to the main OS?

 

5: Is it possible to run PS3MS (PS3 media server) or a media server that can do on the fly transcoding of full 1080p streams on an unraid box as an add on feature?

 

6: Is it possible to have real time sync, rather than the parity updating at an interval in the future like overnight updating?

 

7: What if my USB drive fails with the GUID on it tying it to the licence?

 

8: What performance are people typically getting for reads and writes? The wiki pages mention 20-40mb/s reads, is this not a bit low?

 

 

Many thanks, if I find out the answers to the above as I keep reading I will tick them off.

1: There is a limit with unraid as to the amount of drives that can be used. Why? What possible benefit does this have for the creators of unraid to limit users in this way?

Only Limetech might know the real answer to this, but why does any software company limit what its software can do.  Why do some companies offer multiple version of the same thing (MS Windows, MS Office, Apple FinalCut Express/Pro).

 

2: Can one upgrade the storage inside an unraid array so that if an array was using 10 x 2TB drives, they could swap to using 10 x 3TB drives? i.e. Can you expand the array on the fly without rebuilding from scratch then getting rid of the older smaller disks? If so, then question 1 above isn't so much of an issue. If not, is this going to become a feature?

Of course you can upgrade drive sizes over time.  3TB drives are currently not supported but you can add 22 drives to a current unRAID machine.

 

3: How difficult is it to bundle on extra duties to the OS like torrent and backup clients?

Check the Customization forum, and the wiki.  I have created a Transmission package that can be installed via a community created addon called unMenu.  You can also install Crashplan on your unRAID server to do backups. I run both of these applications on my unRAID machine.

 

4: Is it possible to run XBMC client on an unraid box in addition to the main OS?

No, not that this time.  If you ask me this is not what you want to do anyway.  Use unRAID as a server OS, like it is designed for and get yourself a small ION based nettop to use for XBMC.

 

5: Is it possible to run PS3MS (PS3 media server) or a media server that can do on the fly transcoding of full 1080p streams on an unraid box as an add on feature?

There is a thread in the Applications forum discussing the installation of PS3MS and getting it to do transcoding.

 

6: Is it possible to have real time sync, rather than the parity updating at an interval in the future like overnight updating?

ummmmm, parity does update in real time... there is not a lapse or interval of any sort... any link where you might have read this???

 

7: What if my USB drive fails with the GUID on it tying it to the licence?

LimeTech has always been good about replacing failed flash drives.  They go based on the honor system for the most part.  Though if you start requesting a lot of replacement keys you probably will not get any new ones, and your previous ones might get banned.

 

8: What performance are people typically getting for reads and writes? The wiki pages mention 20-40mb/s reads, is this not a bit low?

20-40 for writes is about right when writing directly to the parity protected array.  If you use a cache drive the writes could/should be faster.  Reads are typically as fast as your network and hardware can support.

7: What if my USB drive fails with the GUID on it tying it to the licence?

 

LimeTech has always been good about replacing failed flash drives.  They go based on the honor system for the most part.  Though if you start requesting a lot of replacement keys you probably will not get any new ones, and your previous ones might get banned.

 

Banned??

 

I wasn't aware there was a Authorization Server

 

 

7: What if my USB drive fails with the GUID on it tying it to the licence?

 

LimeTech has always been good about replacing failed flash drives.  They go based on the honor system for the most part.  Though if you start requesting a lot of replacement keys you probably will not get any new ones, and your previous ones might get banned.

 

Banned??

 

I wasn't aware there was a Authorization Server

 

There is not Authorization server, it does not check home from what we have heard.  There is a "blacklist" in place for keys that do not produce unique GUID's and that mechanism could be used to block other keys should limetech feel that they are being used in the wrong manner. LimeTech may very well add an old key to the list when new key is requested to replace the "broken" flash drive.

7: What if my USB drive fails with the GUID on it tying it to the licence?

 

LimeTech has always been good about replacing failed flash drives.  They go based on the honor system for the most part.  Though if you start requesting a lot of replacement keys you probably will not get any new ones, and your previous ones might get banned.

 

Banned??

 

I wasn't aware there was a Authorization Server

 

There is not Authorization server, it does not check home from what we have heard.  There is a "blacklist" in place for keys that do not produce unique GUID's and that mechanism could be used to block other keys should limetech feel that they are being used in the wrong manner. LimeTech may very well add an old key to the list when new key is requested to replace the "broken" flash drive.

 

 

This would not stop the current version of the software from working. It does prevent blacklisted keys from running any upgrades.

This would not stop the current version of the software from working. It does prevent blacklisted keys from running any upgrades.

Correct, updating the version of unRAID would be out of the question.

Wow thanks for such a quick and informative reply. I think your response highlights why unraid is where it's at for community support which is a big part of my choice for what to go for. Let me reply to the ...errr...replies on a quote by quote basis as below in bold. Thanks again Appreciate it.

 

 

1: There is a limit with unraid as to the amount of drives that can be used. Why? What possible benefit does this have for the creators of unraid to limit users in this way?

Only Limetech might know the real answer to this, but why does any software company limit what its software can do.  Why do some companies offer multiple version of the same thing (MS Windows, MS Office, Apple FinalCut Express/Pro).

 

I can only see the limit as a decision based on not allowing enterprise/business use exploiting a cheap method to get vast storage arrays. However, any serious business would use a RAID/server setup with completely different storage and OS requirments so I can't see it myself. Just seems a bit limiting for no reason really, unless there is a software/hardware issue when using more than the limit.

 

2: Can one upgrade the storage inside an unraid array so that if an array was using 10 x 2TB drives, they could swap to using 10 x 3TB drives? i.e. Can you expand the array on the fly without rebuilding from scratch then getting rid of the older smaller disks? If so, then question 1 above isn't so much of an issue. If not, is this going to become a feature?

Of course you can upgrade drive sizes over time.  3TB drives are currently not supported but you can add 22 drives to a current unRAID machine.

Sorry what I mean is....say in 3 years time, I decide my 22 x 2TB drive unraid box (i.e. I am on the limit) becomes not enough (heaven forbid! but just trying to plan ahead for long term) what if I then want to make it a 22 x 3TB array. Is this possible? I thought one of the issues with unraid was that it couldn't create a new array without re doing everything....hmmm....Maybe I am thinking of zfs/zpool limitations actually.

So to confirm, it can respan/expand in real time so I could have:

 

10 x 1TB

 

and then could add 2 x 1TB drives to make:

 

12 x 1TB

 

and/or could expand it also by adding 2 TB drives if I so wished like:

 

12 x 1TB + 2 x 2TB = 16TB

 

and could just as easily replace them all with 2TB drives making:

 

12 x 2TB?

 

Right?

 

 

3: How difficult is it to bundle on extra duties to the OS like torrent and backup clients?

Check the Customization forum, and the wiki.  I have created a Transmission package that can be installed via a community created addon called unMenu.  You can also install Crashplan on your unRAID server to do backups. I run both of these applications on my unRAID machine.

I will check it out, thanks!

 

4: Is it possible to run XBMC client on an unraid box in addition to the main OS?

No, not that this time.  If you ask me this is not what you want to do anyway.  Use unRAID as a server OS, like it is designed for and get yourself a small ION based nettop to use for XBMC.

I agree, two different tasks. I was trying to save money! But you are right, should use a separate box for the XBMC.

 

5: Is it possible to run PS3MS (PS3 media server) or a media server that can do on the fly transcoding of full 1080p streams on an unraid box as an add on feature?

There is a thread in the Applications forum discussing the installation of PS3MS and getting it to do transcoding.

 

 

I see it! Awesome, looks very promising I will check it out also.

 

6: Is it possible to have real time sync, rather than the parity updating at an interval in the future like overnight updating?

ummmmm, parity does update in real time... there is not a lapse or interval of any sort... any link where you might have read this???

 

I mean, flex raid (sorry to keep bringing it up but looks like the main competitor) used to operate parity by only every calculating on a scheduled basis like say overnight, but now has brought out flex raid LIVE where it does it in real time. Has unraid always been able to calculate and protect instantly in real time then? I was not aware of this.

 

7: What if my USB drive fails with the GUID on it tying it to the licence?

LimeTech has always been good about replacing failed flash drives.  They go based on the honor system for the most part.  Though if you start requesting a lot of replacement keys you probably will not get any new ones, and your previous ones might get banned.

 

OK that's good to hear....but it does put a lot of faith in an individual I do not really know replacing it in the future as a good will gesture. i.e. Just an online entity for specialist storage requirments only contactable via email/web. That's my concern, what if he is not around?

 

8: What performance are people typically getting for reads and writes? The wiki pages mention 20-40mb/s reads, is this not a bit low?

20-40 for writes is about right when writing directly to the parity protected array.  If you use a cache drive the writes could/should be faster.  Reads are typically as fast as your network and hardware can support.

 

 

I understand, sound's somewhat slow to me to be honest, mainly thinking of backup routines, but I guess for media use it's ok as even with HD streams you are not going to need more than 10 or so MB/s? Correct?

 

 

 

 

 

 

One final question...is there any attempt in the future to make it protect for a 2 drive failure, as at the moment I think I am correct in saying that flex raid CAN do this, and can use a cache drive at the same time.

 

One final question...is there any attempt in the future to make it protect for a 2 drive failure, as at the moment I think I am correct in saying that flex raid CAN do this, and can use a cache drive at the same time.[/b]

 

Yes, double parity ( it's called P+Q parity here) can protect from two simultaneous failures...  It's in the "planned" roadmap for 5.x  -- no eta as of yet, but planned.

I can only see the limit as a decision based on not allowing enterprise/business use exploiting a cheap method to get vast storage arrays. However, any serious business would use a RAID/server setup with completely different storage and OS requirments so I can't see it myself. Just seems a bit limiting for no reason really, unless there is a software/hardware issue when using more than the limit.

There might be a slight hardware/software limitation.  Once you go about a certain drive density you are looking at using multiple PSU's to power all the drives, external boxes to get more drives attached, etc.

 

Sorry what I mean is....say in 3 years time, I decide my 22 x 2TB drive unraid box (i.e. I am on the limit) becomes not enough (heaven forbid! but just trying to plan ahead for long term) what if I then want to make it a 22 x 3TB array. Is this possible? I thought one of the issues with unraid was that it couldn't create a new array without re doing everything....hmmm....Maybe I am thinking of zfs/zpool limitations actually.

So to confirm, it can respan/expand in real time so I could have:

 

10 x 1TB

 

and then could add 2 x 1TB drives to make:

 

12 x 1TB

 

and/or could expand it also by adding 2 TB drives if I so wished like:

 

12 x 1TB + 2 x 2TB = 16TB

 

and could just as easily replace them all with 2TB drives making:

 

12 x 2TB?

 

Right?

Yes, you can add drives to unRAID as you like.  The only stipulation is that the parity drive must be as large or larger than your largest data drive.  To expand you pull the smaller drive, insert the new (probably larger) drive, start the array.  unRAID will see a new, larger drive, has been added so will use all other drives plus the parity drive to reconstruct the data onto the new drive.  Drive expansion is done one drive at a time.

 

I mean, flex raid (sorry to keep bringing it up but looks like the main competitor) used to operate parity by only every calculating on a scheduled basis like say overnight, but now has brought out flex raid LIVE where it does it in real time. Has unraid always been able to calculate and protect instantly in real time then? I was not aware of this.

Right, FLEXRaid use to have parity calced on a schedule.  unRAID has ALWAYS has real time parity calculations.  It is the main reason writes to the parity protected array are slower than what you might think they should be.

 

OK that's good to hear....but it does put a lot of faith in an individual I do not really know replacing it in the future as a good will gesture. i.e. Just an online entity for specialist storage requirments only contactable via email/web. That's my concern, what if he is not around?

That is why most of us order the 2 pack of keys.  We keep one as a backup just in case the dog eats the first one.

 

I understand, sound's somewhat slow to me to be honest, mainly thinking of backup routines, but I guess for media use it's ok as even with HD streams you are not going to need more than 10 or so MB/s? Correct?

Assuming all hardware is working correctly you should not have any problems streaming HD content to an XBMC type machine.  You should not have any issue writing HD streams to an unRAID machine also.  A cache drive will help improve write speed

 

One final question...is there any attempt in the future to make it protect for a 2 drive failure, as at the moment I think I am correct in saying that flex raid CAN do this, and can use a cache drive at the same time.

Yes, there has been discussion and it is in the RoadMap.  There have been talks of P+Q parity, Reed-Solomon, Diagonal parity, etc so that 2 drive failures can be handled and no data lost.

OK fantastic. Few more.....

 

1: What about cost of licence. Does the cost/licence cover me for upgrades in the future for life?

 

2: How does unraid box react to power outage/power cut without a UPS. i.e. shutdown unexpectedly?

 

3: How fast do people find their servers boot? Does anyone use it as an "as and when" server or schedule it to only be online during certain hours to save power? I mean sometimes I maybe will only need it on once every few days and I am all for saving power where possible.

OK fantastic. Few more.....

 

1: What about cost of licence. Does the cost/licence cover me for upgrades in the future for life?

Yes.

2: How does unraid box react to power outage/power cut without a UPS. i.e. shutdown unexpectedly?

Like any other linux system a UPS is highly recommended.

 

3: How fast do people find their servers boot? Does anyone use it as an "as and when" server or schedule it to only be online during certain hours to save power? I mean sometimes I maybe will only need it on once every few days and I am all for saving power where possible.

 

Fairly quickly, like any other Linux based system. A lot of people use WOL but your HW must support it.

Most of the time when your machine is on your drives are spun down to conserve energy. I myself like many others us Green Drives so they typically run a bit cooler and at the same time use a bit less energy. You can enable spin up groups so drives spin up and down together too.

 

There is also a few helpful scripts out there such as cache_dir http://lime-technology.com/forum/index.php?topic=4500.0 that will create a listing of your files in Ram so you can browse without actually invoking a spin up of any of your drives until the file is actually clicked on or in most cases a video is requested and then the drive spins up. I normally experience a few second delay, but its well worth it when I'm not needing my drives spinning.

Brilliants stuff. So, if I so wish, I can shut the server down and bring it online as and when I like with no issues? I mean each time I turn it on it won't require hours to reinitialize or anything like that? i.e. It responds as a normal OS in terms of shutdown and startup routines and will not cause problems by NOT running it 24/7?

 

How far away is the much talked about version 5 release? I mean roughly...are we talking this year?

 

 

Thanks for the help!

 

Correct, you can turn on and off your server just like a regular computer.  As long as you shut down the proper way (stopping the array and using the power down button on the web interface, or using the powerdown script) your server should start up the next time with no issues.  Note that both starting and stopping the array requires all disks to spin up, and the default spin up timer is set to 1 hour (and I recommend leaving it at that).  That means that your disks will be spun up for 1 hour every time you turn on the server.  All the disks that aren't used within that hour will then spin down.

 

It is also highly recommended that you use a UPS with your server.  If your server goes down hard (either by you forcing it to shut off the improper way or from a power outage) then it can take a while (up to half an hour maybe) to turn on completely.  This is because the file system has to replay journaled transactions before unRAID can start.  Once unRAID does start, it will automatically kick off a parity check.  Using a UPS and always powering down properly alleviates all of this.

 

No one but LimeTech knows when 5.0 will be ready.  With the stability of the latest beta, I can say that I'll be very surprised if it takes more than the remainder of this year to get it out.  I would hope to see 5.0 stable within a few months, but of course that's just my projection.

Thanks for all your help. Really excited about getting my build going. I have come onto these forums and within a day or two have found out everything I wanted/needed to know, and then some extra stuff as well! The wiki is very useful and the forums are great. Literally everything I wanted to know or understand has been answered. I'm sure more will come as I install it all and think of more questions though! I will certainly look into a UPS, I know it's been on my lift of things to buy for a while. Do the batteries eventually die? What is the lifetime on them?

 

Anyway, I am off to order some 2TB drives and a case I think.

 

 

A APC UPS has the most compatibility with the apcupsd add-on. The add-on can initiate a clean shutdown based on multiple parameters, e.g., when the battery gets low.

I will certainly look into a UPS, I know it's been on my lift of things to buy for a while. Do the batteries eventually die?

Yes. They eventually die.

What is the lifetime on them

About 3 or 4 years.