Motherboard/HardDrive, Component Failsafe Questions + others

[magistratee]

Hey all I am new here to unRAID and was wondering if you could answer some of my questions.  Some may be something that has been asked again (sorry but please bear with me).  There are some software in here questions so if anything is out of place can you please tell me to post in another forum and such.  Thanks.

 

1) unRAID capacity:  free= 3HD's.  plus= 6HD's.  pro= 15HD's.  Do these refer to the data drives or the drives of the whole system.  In other words in the Pro edition do I get 13 data drives + 1 parity + 1 cache =15 HD's or does it mean 15 data drives + 1 parity + 1 cache =17HDs.

 

2) Parity Drive:  Does it really make a difference to have a faster drive for the parity drive?  Is there a performance increase that is noticeable or is it minimal and should be considered insignificant?

 

3) Cache Drive:  Same as parity drive, does it make a difference to have a faster drive?  I read that all the cache drive does is temporarily store the information than transfer it to the other hard drives that is scheduled.  Therefore, does this mean the transfer over the network to the server is actually faster than if there was no cache drive assuming I am only transferring a couple MB or GB (not TB) at a time?

 

4) Motherboard Failure:  What happens in case of a motherboard failure?  Can I just transfer everything to another motherboard assuming I get that motherboard to boot up to unRAID correctly first?  I am assuming that those on a PCI controller can be transferred but those on the motherboard I assume I need the same controller chipset or the next generation such as going from an ICH7 to an ICH10.  Is this right?

 

5) PATA->SATA Transfer:  I am planning to have a mix of SATA and IDE drives.  I know to replace a hard drive you just stop array, power down, change drive, power up, then start the array.  But say I am replacing an IDE drive in the future with a SATA drive, is there a way to maintain the old data into the new drive or should the process work by adding the drive first, transferring data, then get rid of the IDE.

 

6) Data Drives:  Can the data on the hard drives only be accessed through unRAID?  In other words can I stop the array take out a hard drive put it on another computer and that computer can access the data of the drive (data drives of course not the parity)?

 

7) PSU:  Can someone lead me somewhere where I can calculate how much power I need?  I currently have a Corsair 450VX and planning just at most 6 Hard Drives at most (will do more but nowhere in the near or immediate future).  How many HD's can this power efficiently with no drop offs?

 

8 ) 24/7 vs Partial Usage:  Having the server on 24/7 I would need to control my HD spin up and spin down.  I never really had to do this since this is my first time building a server.  If I do not always have it on is this really necessary?  Would it be bad to constantly turn the machine on/off?  I am just planning to have it on during the day, is this a bad idea?  Can someone point me somewhere to where I can decide spin up/down times for my drives.

 

 

Current System to be tested with:

 

MSI P45 Neo3-FR or Gigabyte GA-965P-DQ6

Celeron 430

Corsair 450VX (80+) or Antec Neo HE 500W (not 80+ but was planning to use it if I only use free unRAID or not have server on 24/7, good/bad idea?)

WD RE2 GP HD's + others

 

 

Sorry I know there is a lot here.  If I can get better responses elsewhere can you lead me there cause I am not a frequent user of forums.  Once again thanks for the help.   

 

 

Side Note:  This is off topic but can someone help me deciding between my MSI and Gigabyte board which should be my server (unRAID) and which should be my main system (to be overclocked) assuming I can get both to do unRAID (or if anyone has experiences with these).  [Which is a better overclock?]  I do not do crossfire/SLI.  Can you lead me to a different forum or area to where to ask this.

 

 

[SSD]

You should check out the FAQ, Best of the Forums, and Troubleshooting wiki pages (see my sig) as they'll likely answer these in greater detail than I do below, and also answer a bunch of other questions you didn't even know you had! 

 

1.  Free version = 1 parity + 2 data, plus = 1 parity + 5 data, pro = 1 parity + 15 data + 1 cache

 

2.  Parity drive performance does make a small but noticeable difference.  Trying to have a faster parity disk is recommended.

 

3.  Writes to the cache disk are fast.  A faster drive may yield faster performance in some situations.  But likely network throughput will be more limiting than drive speed.  That being said, I replaced an IDE cache disk with a SATA drive and had a noticeable increase in write performance in some applications.

 

4.  Yes - you can move your array to another motherboard.

 

5.  Mix of drives is fine.  Replacing IDE with Sata is fine.

 

6.  Data drives are formatted with ReiserFS.  They can be read in another Linux system or in Windows if a special driver is installed.

 

7.  Six drives with a 450 watt PSU should be more than fine.  Sometimes PSUs use multiple rails, however, and do not supply as much power to the peripherals as expected.  Single rail PSUs are therefore recommended.  But even if this is multi-rail, 6 drives is a pretty easy load for a 450 watt PSU.  I am running 16 drives off of a 550 watt PSU.  The type of drive also matters - WD Green drives use 1/2 the power of std drives.

 

8. You can leave the machine on 24x7 or power up and down each day.  Up to you.  Drive spin up / spin down times are a religious question.    Everyone has their opinion.  There is no good data to help make the decision except common sense.  I have mine set to 5 hours.

 

Your motherboard choice is an important one.  Look for a board that several other users have had success with.  The SuperMicro C2SEE MB is the one used by Limetech in the preconfigured servers they sell, and is a good choice.

 

[magistratee]

Thanks for all the help.  You helped a lot  .  Looks like I have to play with unRAID for a while to get a feel for it.  Thx.