Hi,

 

I have just noticed that my NAS is getting very full so I thought it time to add some more disks. My plan is laid out below but I have a few questions I hope people in the know will indulge me with.

 

I run Unraid 5.04.

 

System: ASUSTeK COMPUTER INC. - P8B75-M LX

CPU: Intel® Celeron® CPU G550 @ 2.60GHz

Cache: 32 kB, 256 kB, 2048 kB

Memory: 4096 MB (max. 16 GB)

 

Total Usage: 94%

Parity: WDC_WD30EFRX-68AX9N0_WD-WMC1T2161763 (sdc) 36 °C 3 TB      14,087,050 1,635,992 0

Disk 1: WDC_WD30EFRX-68AX9N0_WD-WMC1T1731539 (sdd) 38 °C 3 TB       2.83 TB      169 GB      9,531,627 2461 0         Browse /mnt/disk1

Disk 2: WDC_WD30EFRX-68AX9N0_WD-WMC1T2270167 (sde) 35 °C 3 TB      2.82 TB        185 GB      11,460,525 512,709 0         Browse /mnt/disk2

Disk 3: WDC_WD30EFRX-68AX9N0_WD-WMC1T1962776 (sdf) 35 °C 3 TB       2.82 TB        185 GB      14,554,975 1,124,688 0 Browse /mnt/disk3

Cache: WDC_WD30EFRX-68AX9N0_WD-WMC1T1955103 (sdb) 37 °C 3 TB       859 GB        2.14 TB      23,960,378 10,701,636 0    Browse /mnt/cache

 

 

I plan on buy 2x WD Red 6TB NAS HDD 3.5" 6Gb/s Intellipower WD60EFRX (http://www.cplonline.com.au/wd-red-6tb-nas-hdd-3-5-6gb-s-intellipower-wd60efrx.html). I see no benefit in getting the WD Red Pro drives. I would have stumped with a Seagate NAS drive if everything I have already wasn't WD. I like uniformity - even if it is pointless.

 

I am buying 2 because I believe I have to increase the size of my Cache drive to match the largest drive in the array. I plan on installing the two drives. Then in the Admin GUI moving the existing 3TB cache drive into the array. Adding a 6TB drive as the Cache. Then adding another 6TB drive into the array. Then let the magic happen.

 

Q1. What about the parity drive. Do I need to increase the size of this drive too? At what point does a 3TB parity drive become too small for such a large array of data?

 

Q2 (or discussion 2 ). Do I have any options with respect to pre_clear. From everything I have read I should pre_clear BEFORE I put the drives into the Unraid box. Thats all well and good but I only have an iMac 27" and a HP laptop with no USB 3. I thought about running a VM (Virtualbox) with Unriad and running pre_clear against the 6TB drives attached to the iMac in a USB3 enclosure. Some threads I have read have said you can't do this because Virtualbox doesn't have direct disk access - but then I read this:

 

 

https://www.virtualbox.org/manual/ch09.html

 

"9.9.1.1. Access to entire physical hard disk

 

While this variant is the simplest to set up, you must be aware that this will give a guest operating system direct and full access to an entire physical disk. If your host operating system is also booted from this disk, please take special care to not access the partition from the guest at all. On the positive side, the physical disk can be repartitioned in arbitrary ways without having to recreate the image file that gives access to the raw disk."

 

 

Does anyone have any experience with this, or if it is impossible is there an alternative to run pre_clear externally to my current NAS setup with the hardware I have?

 

Hopefully I am on the right track. I appreciate any comments about any of what I have written from the community.

 

 

Thank you in advance.

 

Daniel

Couple points that stick out.

1. Cache size is unimportant for this discussion. Parity is the one that has to be as big or bigger than any of the rest of the array members.

2. It is actually beneficial to run the preclear on the new drives in the physical spot they are going to live. That way you are testing the entire connection chain, from controller to cable to drive bay and power supply. The "not adding drive to unraid until it's precleared" means not assigning it as an array member. It can be precleared in your unraid box just fine as long as you have the extra connections available. Just don't assign it to the array until after the preclear is done.

You want to run pre-clear before you add the disk to the array, but that's a logical step.  Physically, it's fine to put the disk in your unRAID box.

 

You may find bjp999's instructions to upgrade parity helpful.

You want to run pre-clear before you add the disk to the array, but that's a logical step.  Physically, it's fine to put the disk in your unRAID box.

 

2. It is actually beneficial to run the preclear on the new drives in the physical spot they are going to live. That way you are testing the entire connection chain, from controller to cable to drive bay and power supply. The "not adding drive to unraid until it's precleared" means not assigning it as an array member. It can be precleared in your unraid box just fine as long as you have the extra connections available. Just don't assign it to the array until after the preclear is done.

 

I completely misunderstood. Thats excellent news. Thank you.

 

 

You may find bjp999's instructions to upgrade parity helpful.

 

Couple points that stick out.

1. Cache size is unimportant for this discussion. Parity is the one that has to be as big or bigger than any of the rest of the array members.

 

I was reading the guide last night before I went to bed and it is excellent. Thanks for confirming it for me.

 

 

Maybe I was tired but it makes sense now. I guess the Cache drive could be any size but would most likely be based on how much I download in any 24 hour period (between mover executions) - given I don't get close to filling 3TB in any one 24 hour period - I can leave that drive as is. [EDIT] Orrrrr ..... a smaller SSD Cache drive is sounding better now too!

 

So my task becomes replacing the Parity with a 6TB drive and adding another 6TB drive (and the old Parity drive) to the array. Doesn't appear that anything I do hear impacts my future upgrading to 6.x either so all is good.

 

Ill report how it goes! Thanks guys!

Maybe I was tired but it makes sense now. I guess the Cache drive could be any size but would most likely be based on how much I download in any 24 hour period (between mover executions) - given I don't get close to filling 3TB in any one 24 hour period - I can leave that drive as is. [EDIT] Orrrrr ..... a smaller SSD Cache drive is sounding better now too!

 

So my task becomes replacing the Parity with a 6TB drive and adding another 6TB drive (and the old Parity drive) to the array. Doesn't appear that anything I do hear impacts my future upgrading to 6.x either so all is good.

 

Ill report how it goes! Thanks guys!

 

You got it, good luck and ask for help if you need it along the way!

Just wanted to point out you don't have to buy 2 6tb drives right now. You can buy just one, use it to replace the parity then you'll have a free 3tb drive to add to the array.

As for the preclear - my best-practice advice for building an unraid server is leaving one SATA+power connector free for future upgrades & maintanance...

Just wanted to point out you don't have to buy 2 6tb drives right now. You can buy just one, use it to replace the parity then you'll have a free 3tb drive to add to the array.

As for the preclear - my best-practice advice for building an unraid server is leaving one SATA+power connector free for future upgrades & maintanance...

 

Thanks, I had missed that! I think I will do that actually and save a bit more money before Christmas.

 

You also prompted me to have a look inside my Antec P183 V3 for space etc. I have the bottom cage filled and have 1 disk in the cage above that. Ill stick the new 6TB in that cage but will have to look at buying some 5in3's for the future. I know I can get up to 12 disks in there!

 

Also had a look at my SATA ports and there is only one port left. An expansion card or 2 is going to be required too. Sigh, more research - but at least I can get one disk in there now! The Motherboard I have (P8B75-M LX - http://www.asus.com/Motherboards/P8B75M_LE/specifications/) has 5 x SATA 3Gb/s port(s), blue 1 x SATA 6Gb/s port(s), grey  -I feel my Cache drive should be on the 6Gbps port and the 5 3TB drives should be on the 3Gb/s port!

All finished. Flexibility of Unraid demonstrated and I love it. Ended up putting in an old WD GREEN 2TB in the box as the 3TB I had there was a waste of space. Got plenty more space and saved having to spend some money!

 

No expansion cards or 5in3's required yet either. No more SATA ports or SATA power cables left though, so it will happen!

 

This is what I did ....

 

Disabled Plugins (these all use Cache Drive), Pre Cleared 2TB Drive, Backup Cache Drive, Changed 3TB Cache Drive to data disk 4 and Selected 2TB WD GREEN as Cache Drive, Cleared Disk 4 using GUI, Reboot, Expanded Array, Reboot, Formatted Both Drives using GUI, Started Array,  Reboot, Restored contents of Cache Drive from Backup. Re-enabled Plugins . Bobs your uncle.

 

Notes: I had the following issues:

 

Dynamix Webgui crashed three times. Once when I expanded the array and once when  I had to format the drives. It appears all was still working in the background so all I had to do was restart the web server in a telnet session enough to allow me to ensure all was good and then clean reboot.

 

When I added the new disk it changed my boot settings in the bios (to no longer be the USB drive) so I had to go in and change that back.

 

Didn't appear to need to do / ask for a parity check after the expansion, which made me pause. Then I had to assume this was because there was no data on the 4th disk and therefore no need.

 

All is good though, now have my array expanded from 9TB to 12TB. Happy Days.