Hey all, 

 

I am pretty new to this but I just set up my old pc using unraid to test if it could potentially be my storage solution for video editing. I am rocking an i5-4690, asrock H97 Pro4 (1gb LAN, 6 sata ports), 8gb ram, gtx 770 4gb, a 1tb WD Caviar Blue as my disk, and a 250gb Samsung EVO 850 as the cache. After doing some test I am currently getting around 40mb/s read/write speeds on my Macbook over wifi (I understand I'd probably get better speeds on LAN).

 

If I potentially upgrade this system I was thinking of getting two 12gb seagate ironwolf drives, one more ssd, and a 10gb/s NIC. I would create a parity with one of the ironwolf drives and then have the second ssd added to the cache pool for redundancy. 

 

Would this create faster speeds? 

Will both the disks and cache have a safety-net? 

Is the 10gb/s NIC overkill?

If I end up wanting to edit off of the server would I need better ssds for cache?

 

Thanks!

Edited December 15, 20214 yr by banter

1 hour ago, banter said:

Would this create faster speeds? 

As long as parity is involved, write speeds to the array will be limited to around 40 -70 Mbps.  For speed sensitive writing, the original use of the cache drive is to write data there first (at the speed of the SSD) and let the mover write the data to the array at the slower speeds, usually at night, when there is little activity on the server.

 

1 hour ago, banter said:

Is the 10gb/s NIC overkill?

It depends.  Most HDDs are limited to around 200 Mbps in best case-scenarios (without parity) and 1 Gbit is plenty of bandwidth for that.  Now, if you want to move data between an NVMe SSD on a client machine and and NVMe cache drive on the server, a 10 Gbit NIC is going to give you more bandwidth to do that.

 

1 hour ago, banter said:

Will both the disks and cache have a safety-net? 

The parity drive(s) provide the "safety net" for array disks but only protect against disk failure.  Parity is not a backup of your data and you should have another solution for that.   If you only have only one data disk and one parity disk, the parity disk will essentially be a backup of the data disk; however, as soon as you introduce another data disk, that is no longer the case.  Parity contains a calculation of the data at a particular location on all the data disks.  If one goes missing, the parity disk together with ALL the other data disks can be read to reconstruct the missing data onto a replacement HDD.

 

Beginning with unRAID 6.9.x, you can have multiple drives in "cache pools" with RAID1 redundancy being the the default configuration.  That would give you a "safety net" against a drive failure in the cache pool.  Other configurations are possible that do not involve redundancy.

Edited December 15, 20214 yr by Hoopster

20 minutes ago, Hoopster said:

As long as parity is involved, write speeds to the array will be limited to around 40 -70 Mbps.  For speed sensitive writing, the original use of the cache drive it to write data there first (at the speed of the SSD) and let the mover write the data to the array at the slower speeds, usually at night when there is little activity on the server.

I first want to say I really appreciate the responses! So write speeds depend on how fast your cache is and how big it is? And then what is the best way to have faster read times from the array? More drives? Thanks again!

2 minutes ago, banter said:

So write speeds depend on how fast your cache is and how big it is?

If you are using a cache drive, yes, fast matters.  When data is written to the array protected by a parity drive, you can expect 40-70 Mbps on average.  Size of the cache drive does not factor too much into speed with SSDs.

 

4 minutes ago, banter said:

And then what is the best way to have faster read times from the array?

All files on an unRAID array exist on a single disk.  There is no striping across multiple disks like there is with RAID.  Therefore, the fastest a file can be read will be determined by the read speed of the disk on which it is stored.

7 minutes ago, Hoopster said:

All files on an unRAID array exist on a single disk.  There is no striping across multiple disks like there is with RAID.  Therefore, the fastest a file can be read will be determined by the read speed of the disk on which it is stored.

I understand. Thanks again!