Starting a new unRAID server off with a single 2TB drive, bad idea?

[3560freak]

I have finally compiled all of my components together for my build, however I am wondering if starting off with just one WD20EADS is a bad idea.  If I do this will I be required to add just 2TB size HDD or larger in order to keep data on the original WD20EADS?  From what I can gather using the Wiki it looks like the largest drive is always considered the parity drive.  I am just starting out with the free version of unRAID to see if it fits my needs, which is basically hosting media to 2 PCs and 1 WD TV Live Media box.  I was looking at the WD20EADS because it is the best bang for the buck (approx $140) vs 2 * WD10EARS (approx $160 total).  Thank you for the help

[purko]

I am wondering if starting off with just one WD20EADS is a bad idea.  

If I do this will I be required to add just 2TB size HDD or larger in order to keep data on the original WD20EADS?

It's not bad or good, it's up to you.  You can start with only one data disk just fine.

Later, when you decide that you want to add a parity disk, it will have to be at least that big.

 

[unraided]

Why not buy a few disks? Do you have a free, Plus or Pro licence? If you have a free licence, you can have only two data disks and one parity, Plus has five data and one parity, or Pro nineteen data and one parity (or minus a data disk and have one cache disk).

Their are a lot of deals now on disks, I'm seeing some good deals for Western Digital and Seagates (1TB to 1.5TBs) going about $10 to $20 cheaper now. Depending on your region/location, (well I'm in Australia), at the moment it would be way cheaper if you bought a 2TB disk to use as a parity drive and two 1TB disks and use them as data, but again, it depends on your location and prices vary from country to country.

[terrastrife]

Why not buy a few disks? Do you have a free, Plus or Pro licence? If you have a free licence, you can have only two data disks and one parity, Plus has five data and one parity, or Pro nineteen data and one parity (or minus a data disk and have one cache disk).

Their are a lot of deals now on disks, I'm seeing some good deals for Western Digital and Seagates (1TB to 1.5TBs) going about $10 to $20 cheaper now. Depending on your region/location, (well I'm in Australia), at the moment it would be way cheaper if you bought a 2TB disk to use as a parity drive and two 1TB disks and use them as data, but again, it depends on your location and prices vary from country to country.

 

because the OP doesnt know if unRAID is what they want to do yet, as stated.

 

not all of us have the money to go out ad buy 3x 2TB disks on the spot for 'testing software'.

[boof]

I have finally compiled all of my components together for my build, however I am wondering if starting off with just one WD20EADS is a bad idea.  If I do this will I be required to add just 2TB size HDD or larger in order to keep data on the original WD20EADS?  From what I can gather using the Wiki it looks like the largest drive is always considered the parity drive.  I am just starting out with the free version of unRAID to see if it fits my needs, which is basically hosting media to 2 PCs and 1 WD TV Live Media box.  I was looking at the WD20EADS because it is the best bang for the buck (approx $140) vs 2 * WD10EARS (approx $160 total).  Thank you for the help

 

If you decide to expand you would need another 2Tb (or larger if such a thing should exist by that time) as your parity drive to provide protection to your existing 2TB disks worth of data.

 

After that, however, you are free to add any size drive - so long as it's equal to or less than the 2TB size of your parity drive in the example above.

 

So you're not stuck with only 2TB disks at all and you can add incrementally as time / budget / disk availability suits. As purko said, only your next purchase (parity) will need to be 2TB. Technically you could buy more disks and not assign any of them as parity - but then you would be losing all data protection so I (we) are assuming you would want parity protection as your next step.

 

The largest drive is not automatically configured by unraid to be parity - you still manually choose which drive in your machine to make the parity drive. In fact you manually assign all drives in your machine as parity / data / cache unraid won't automatically do this for you. However whichever drive you choose does have to follow the same size or bigger rule above.

 

You will have no problems over data loss of your existing data provided you follow the manual / instructions / forum advice during your upgrade!

[Kaygee]

I'm not sure testing unraid with a single disk is really testing unraid?

 

First thing I did was copy some data to a parity protected drive and unplugged a data drive to see if I could still read the data. Once this was proven a few MD5 tests to make sure data was valid, then some speed tests, then some load tests.

 

For me the #1 feature of unraid is parity protection. Without two disks you cant test it. 

[unraided]

Hi terrastrife, to my understanding the person was asking the question of single disk testing, secondly I didn't suggest to buy 3x 2TB drives, just buy 1x 2TB drive as parity and buy a couple of either 1 to 1.5TB drives as data seeing he was going to buy new disks anyways. For the sake of testing, why buy disks at all? If you have some older SATA disks lying around, build a testbed and do some real world tests, obviously speed will be different on older SATA disks though. Before I got into unraid, I built a testing rig with 3x 40GB SATA disks and tried out everything from split levels, to shares, speed testing, redundancy and even addons. This helped me to like unraid even more. Hope this helps.

 

Why not buy a few disks? Do you have a free, Plus or Pro licence? If you have a free licence, you can have only two data disks and one parity, Plus has five data and one parity, or Pro nineteen data and one parity (or minus a data disk and have one cache disk).

Their are a lot of deals now on disks, I'm seeing some good deals for Western Digital and Seagates (1TB to 1.5TBs) going about $10 to $20 cheaper now. Depending on your region/location, (well I'm in Australia), at the moment it would be way cheaper if you bought a 2TB disk to use as a parity drive and two 1TB disks and use them as data, but again, it depends on your location and prices vary from country to country.

 

because the OP doesnt know if unRAID is what they want to do yet, as stated.

 

not all of us have the money to go out ad buy 3x 2TB disks on the spot for 'testing software'.

[SSD]

In order to run a protected array you'd need at least 2 disks - one data and one parity. The parity disks needs to be equal or greater size.

 

With a single 2T drive you would set it up as a data disk. Your "array" would not be protected. There is a lot you could learn about and explore in unRaid with this configuration, but also a lot you'd be missing out on.

[WeeboTech]

In order to run a protected array you'd need at least 2 disks - one data and one parity. The parity disks needs to be equal or greater size.

 

With a single 2T drive you would set it up as a data disk. Your "array" would not be protected. There is a lot you could learn about and explore in unRaid with this configuration, but also a lot you'd be missing out on.

 

I dunno if anything other then "protection" would be missed. All other options would exist.

What could be an issue is the lost opportunity in testing how the array handles failures without worrying about stored data.

 

Other then that unRAID will function correctly albeit without protection of your data.

[Rajahal]

The following would all be missing from your 'test':

• Parity protection (and subsequently the ability to recover from a drive failure)
  
• Split levels (you will have the option to set them, but they won't do anything since there is only one disk)
  
• User Shares (again, you can use them, but they won't really do anything since you won't have multiple drives to be combined into one unified view)
  
• Cache drive (only available with a Pro license anyway)
  

 

You will also see artificially high write speeds since unRAID won't be calculating parity during writes...

 

So an unRAID server with only one drive is essentially a networked external hard drive with a few extra frills.  It will tell you a few bits of useful information - that your motherboard is compatible, for example.  However, a full test of unRAID requires both a parity build AND a parity check, then an inspection of the syslog (by experienced members on these forums).  Only then will you know you can really trust your server with your data.

 

I would recommend unraided's approach - buy a 2 TB drive as a parity drive, then pop in as many spare drives as you can find of any size and speed as data drives.

[Rajahal]

He also asked if it was a bad idea.  In my opinion, yes it is a bad idea if you want to test out unRAID's capabilities and features.

[BRiT]

Simple answer: Yes, but it's a bad idea.

 

As others have already pointed out, you wont be experiencing how unRAID will function with parity and with different shares. However, you can see if your motherboard/nic/memory play nicely with unRAID and can also try out the various feature addons.

[Joe L.]

The guy can afford just one disk at this time.  So yes, it's a good idea.  When he can afford more disks, he can easily grow his array.

True, and he can scrounge and or be given old cast-off drives to use to play with.  a 2TB drive as parity, and a 100gig cast-off as data will let him play with all the features.  It won't give as much storage, but you can test the other hardware.

 

On the other hand, a single 2TB drive and no parity just makes the unRAID server seem just like any other networked 2TB drive.  Still very usable, just no protection from a drive failure.

[unraided]

Exactly, normally us tech savvy guys would have some spare disks lying around to use on a test rig, if not, you could buy 40 - 80GB disks as cheap is buying a coffee and muffin or I'm sure a friend would scarfice their paper weights and give them to you. You can run unraid one drive yes, like you can run a four cyclinder engine on two cyclinder, but why would you? For the sake of understanding and learning unraid (and to get to like it and take advantages of it's common features), I would and other seen to recommend to get a three disk rig up and running to properly test it out.

[Rajahal]

If you don't have spare hard drives laying around, you may want to check with a local computer hardware store.  There's a store in my town that will give away (for free) any hardware that they deem obsolete, stuff that has no resale value.  I imagine any drive under 10 or 20 GBs would qualify in this category, though they are likely to be IDE and not SATA.  The smallest SATA drive I've ever seen is 40 GB.

[3560freak]

Thank you for all of the suggestions.  So after reading a few of these posts I decided to pony up a little more cash and go with 2 * 1.5TB drive instead of the 1 * 2TB.  I found a great deal that was not actually too much more than the single drive.  2 * WD15EARS for $89.99 each.  So here I go 

[Rajahal]

Good choice.  You lose 500 GBs of capacity, but you gain parity protection, which is worth its weight in gold.

 

I guess that doesn't really make sense, because parity is more of a concept than a material object, but still....

...it's Friday, I don't have to make sense.

[BRiT]

That's not too bad of a trade off I guess, giving up 500 Gigs of space to save $60 (2TB drive deals posted for $119).

[unraided]

Very good, in the end, you need to see what is more of value, as prices go down, 2TB disks would be better to buy, but atm it is the 1.5TB disks that seem to have more value for the size and price. I would suggest that you do all the testing you can think of (simulate disk failure, install addons, etc... ) before you start placing your important data onto any production server that you'll build for the long run, as this will give you re-assurance knowing that if a particular circumstance were to occur, you know what to do. Though their is always the unraid wiki and forum to bail you out of trouble . Good Luck.

 

Thank you for all of the suggestions.  So after reading a few of these posts I decided to pony up a little more cash and go with 2 * 1.5TB drive instead of the 1 * 2TB.  I found a great deal that was not actually too much more than the single drive.  2 * WD15EARS for $89.99 each.  So here I go   

[3560freak]

Thank you for all of the suggestions.  So after reading a few of these posts I decided to pony up a little more cash and go with 2 * 1.5TB drive instead of the 1 * 2TB.  I found a great deal that was not actually too much more than the single drive.  2 * WD15EARS for $89.99 each.  So here I go   

Just a note: when you get those drives, don't forget to put jumpers on pins 7-8 before you put them in the server.

 

Yeah, interestingly enough it is actually printed on the outside of the drive

Windows XP single partition - set jumpers 7-8 prior to installation

so I guess it applies to *nix too

[3560freak]

Well I once again ended up spending money that should have been saved for other things  and picked up one more 1.5TB drive for a total of 3 (2 data, 1 parity) for my trial on the free release.  I got everything up and running as far as the install goes (it's creating the array as we speak) but I keep on finding posts talking about people needing to use a preclear utility before putting data on the drive (to ensure you drives are not about to fail off the bat, DOA).  Does everyone find this necessary or is it just a suggestion for questionable old drives?

[Joe L.]

Well I once again ended up spending money that should have been saved for other things  and picked up one more 1.5TB drive for a total of 3 (2 data, 1 parity) for my trial on the free release.  I got everything up and running as far as the install goes (it's creating the array as we speak) but I keep on finding posts talking about people needing to use a preclear utility before putting data on the drive (to ensure you drives are not about to fail off the bat, DOA).  Does everyone find this necessary or is it just a suggestion for questionable old drives?

It is never "necessary"

 

It helps to detect drives that fail in the first few hours of use... before you put your data on them.  (There have been a small number identified in this way bu the pre-clear process...  I can't tell you percentage wise... but it is helpful)

 

It helps to identify drive with initially bad sectors, before you put your data on those sectors.  It does not prevent future un-readable sectors, but it helps again to weed out drives prone to an early failure.

 

Once you assign a parity disk to your array, pre-clearing a new data disk will eliminate a lengthy off-line time of the array when adding a new disk to the array.  If you do not pre-clear the disk before adding it to the array, unRAID will clear it for you, but the array will be off-line during this phase.  Now, it just "writes" zeros to the drive, so "un-readable" sectors are not initially identified until you do the first parity check. 

 

The clearing of a 2TB drive will take 5 to 6 hours if you can write to it at 100MB/s, or more if it is a slower disk.  If you have no need for the server to be online for that period, then don't pre-clear.  By pre-clearing the array down-time is that needed to stop the array and assign the new pre-cleared disk.  You are back up and running in a minute.  It is not "necessary" but nice... especially if a family member really wanted to watch a movie...

 

Therefore, the pre-clearing is just as important to me on older disks as on new disks.  I know my wife uses our server a lot, and a lengthy down-time is not going to make her happy.  It just becomes part of what we expect to always be there.

 

Joe L.

[unraided]

I've never done a pre_clear (I've only installed brand new disks into my rig). I simply slot the disk in, verify it detects in BIOS, boot unraid, assign the disk, check and format the newly created disk via the unraid web gui.

[unraided]

No harm in doing a pre-clear though, but as Joe L stated, quote:

 

It is never "necessary"

 

It helps to detect drives that fail in the first few hours of use... before you put your data on them.  (There have been a small number identified in this way bu the pre-clear process...  I can't tell you percentage wise... but it is helpful)

 

So if you're paranoid, just do it I guess.

[SSD]

To summarize ...

- the chances of preclear finding a problem on a new disk is very low (I personally have precleared 12 disks and it has never found a problem)

- the benefit of finding a problem before you add a disk to the array is high

- running preclear before adding new disks to an existing array prevents a lengthy clearing cycle in unRaid