Getting ready for my first build. I have at my disposal a Dell T3600 with an E5-1660, some 3.5" HDDs, and an H310. I plan on putting Unraid and Plex on this box. It appears that the T3600 has built-in software RAID by Intel. Would I benefit by using the H310 instead of the software RAID? In what way?

Edited October 24, 20196 yr by Willion

RAID is not recommended and can cause numerous problems. Unraid is NOT RAID. 

13 hours ago, Willion said:

Would I benefit by using the H310 instead of the software RAID?

If you need more drives in the array than the number supported by MB SATA ports, the Dell H310 will work well; however, it should be crossflashed with LSI 9211-8i firmware in IT mode (version 20.00.07.00 is the latest), and should not be left in RAID mode.

 

I personally have a Dell H310 in IT mode running in my main server as do many others.

 

As trurl mentioned, unRAID (as the name suggests) is not RAID.  Not being a RAID implementation, it has certain advantages and disadvantages compared to RAID, but, for most, the advantages are why we are all unRAID users.

Thank you. I had read about Unraid but obviously not enough because I didn't realize it wasn't RAID. I'll do some more research.

2 hours ago, Willion said:

Thank you. I had read about Unraid but obviously not enough because I didn't realize it wasn't RAID. I'll do some more research.

The primary advantages of unRAID over RAID is that it allows you to add any disk of any size to the array easily.  Disks in the array do not have to be the same size and model as is often the requirement for RAID implementations.

 

Also, with unRAID, if you lose more data disks than are protected by parity ( 1 or 2 depending on parity implementation), you only lose the data on those disks and not the entire data set as you do with RAID.

 

unRAID array disks each contain their own filesystem and can be read directly by many Linux systems outside of the unRAID array.  This also brings up the biggest "disadvantage" with unRAID and that is that data is NOT striped across disks and, therefore, write speeds (and reads) are limited to the speed of a single disk.  There are some ways to mitigate that, but, unRAID will always be slower at writing data than a RAID.

Edited October 25, 20196 yr by Hoopster

I see. If Unraid is slower, can that speed be improved upon by using a RAID card with RAM but not in RAID mode? I'm presuming without knowing that you still get the benefit of caching from the card even if RAID mode is turned off.

Unraid write speed can be increased by using a cache drive (with no data protection until transferred to the array)  or a cache pool (with the proper setup of the cache pool, you will have parity data protection).  If you use SSD's for the cache, your write speeds will exceed 1Gbps.  See here for a description of how Unriad works:

 

     https://wiki.unraid.net/index.php/UnRAID_Manual_6#Network_Attached_Storage

 

You might want to peruse the rest of this manual as it gives a good overview of how Unraid works. It is the early version and this is a link to the latest one:

 

    https://wiki.unraid.net/index.php/Official_Documentation

Edited October 27, 20196 yr by Frank1940

Thanks for all of the good info. It looks like I might be using the Perc H310 after all because the PC I ended up using for the project has an ASUS P8P67 motherboard and it doesn't appear to recognize large HDDs. I have put an 8 TB disk in and it doesn't show up at all, not even in the BIOS so I am in the process of cross flashing the H310.

23 hours ago, Willion said:

I have put an 8 TB disk in and it doesn't show up at all

It's possible that has more to do with the SATA 3.3V reset issue than the controller.

Interesting, I was not aware of this issue. I'm using Hitachi huh721008ale600 drives. I've read up on it and I'll get a Molex to SATA power adapter and test this out.

On 1/3/2020 at 1:01 PM, jonathanm said:

It's possible that has more to do with the SATA 3.3V reset issue than the controller.

jonathanm,

You were right. I used a Molex to SATA power adapter and now any of those disks show up just fine. Thank you very much!