I'm new to Unraid and know very little about linux.  My questions is about the Parity drive.

 

Is it possible to build the parity drive on demand or is it always on?  I'm running Unraid as a home server and stuff only gets added to it occasionally.  I'd like to be able to build the parity once in a while and otherwise have it remain spun down.  I saw some topic about an automatic parity check but I wasn't sure if "parity check" means rebuilding parity or if it's just a safety check.  If it does mean rebuilding then is it possible to schedule them because only building parity once per month would scare me as too infrequent.

 

My setup:

I set up a 3 drive Unraid system and have added disk1 and disk2.  I'm going to add the parity disk in a few days when I can clear off another hd.

My system is a Shuttle SV25 (yep, it's ancient) with a cheap syba 2-port pci sata card.  An SV25 won't boot from usb so I'm booting Unraid from a compact flash drive attached to the IDE port.  It's running an Intel P3 900Mhz with 768 Mbytes of ram.  Using the built in 10/100 Nic it's able to move 6.8 MB/s which is plenty fast enough for a home movie server. 

I only use seagate 7200 rpm drives and so far they are running between 34c and 38c. 

 

I'm new to Unraid and know very little about linux.  My questions is about the Parity drive.

 

Is it possible to build the parity drive on demand or is it always on?  I'm running Unraid as a home server and stuff only gets added to it occasionally.  I'd like to be able to build the parity once in a while and otherwise have it remain spun down.  I saw some topic about an automatic parity check but I wasn't sure if "parity check" means rebuilding parity or if it's just a safety check.  If it does mean rebuilding then is it possible to schedule them because only building parity once per month would scare me as too infrequent.

 

My setup:

I set up a 3 drive Unraid system and have added disk1 and disk2.  I'm going to add the parity disk in a few days when I can clear off another hd.

My system is a Shuttle SV25 (yep, it's ancient) with a cheap syba 2-port pci sata card.  An SV25 won't boot from usb so I'm booting Unraid from a compact flash drive attached to the IDE port.  It's running an Intel P3 900Mhz with 768 Mbytes of ram.  Using the built in 10/100 Nic it's able to move 6.8 MB/s which is plenty fast enough for a home movie server. 

I only use seagate 7200 rpm drives and so far they are running between 34c and 38c. 

 

Once the initial parity calculations are performed the parity disk will only be written to when a data disk is written to.  If no writes to the array occur the parity disk will spin down, and most of the time, it is spun down.  (in my array is spins up when I add a new movie, but most of the time it is spun down.)

 

Parity is immediately calculated when ANY write occurs, so you do not need to do anything to have it in sync with your data.  The monthly parity check we suggest you perform is to ensure your disks are working properly, not to actually calculate parity.  It is to detect a defect that would otherwise go undetected until a second disk fails.....  It is, as you described, a "safety check" 

 

Your disks are a tiny bit on the warm side, but if in heavy use my disks get as warm.  When spun down my disks get down to the low 20s.

 

You older hardware will do just fine.  It is not as fast as some, but as you said, for home media use, the 100Mb LAN can handle most.  (That is all my media players have as a NIC anyway... none have Gbit.)  If you outgrow it, it will be easy to migrate your disks to a different MB/disk controller.

 

Joe L.

 

 

 

May I suggest you check out the User Contributed section of the unRAID Wiki, and specifically the FAQ?  It contains a number of topics on various aspects of parity, as well as many other subjects, unRAID related.