I currently have 6 drives on an Abit ip 35 pro around 98 percent full. I have terrible performance. Can't do two things at once.  Folder access is very slow.  If I am copying something to the array and try to even explore the array it is very slow including GUI access. Sometimes large files fail to copy which I only realise after watching half a movie! I want to increase the performance of my unraid box and am thinking of two options. I want to install a aoc-saslp-mv8 raid card hoping to improve performance. I understand that 2 of the 6 ports on the motherboard are slower than the rest so hoping this will improve things.  Also it seems the nic on this motherboard runs off the pci bus so am looking at putting in a dedicated gigabit nic. Are these two ideas a good way to go? Is there anything else I can do to improve performance?

 

Thanks for taking the time to read my post.

The key to your poor performance is the simple fact that your array is "... 98 percent full."

 

You shouldn't have any real issues streaming content IF you aren't doing any writes ... but writes to a very full array are VERY slow, and can impact other activity that is going on at the same time.

 

Clearly what you need to do is add some additional ports (an MV8 will do that) AND add some additional drives, so you're not writing to full drives.

 

The NIC should be fine as long as it's a Gb NIC.    If not, then adding a Gb card is a good idea.

 

Thanks for your reply.  If I add more drives should I move data from existing disks to the new drives or is it dependent on the free space available on the whole array and not individual disks.  Also with the extra card should I share the drives between the raid card and on board or stick with the raid card solely? Also,  is this the reason why I am having large files fail to copy? There is enough space for each file but is it failing because the drives are nearly full?

No need to move data from the current drives -- it's not the reading activity that slows things down;  it's when you write to a very full drive.

 

Once you add additional drives, all of the writes will be to those new drives (assuming you've set your allocation algorithm to either high-water or most-free) ... so you won't have the issue with writes that you're seeing now.

 

... I would not move the connections off of the onboard SATA ports => just add your new drives to the new interface card you're buying.

 

As for why files would fail altogether ... as long as their is enough space on the selected drive for the file, it SHOULD copy okay (although very slowly if the disk is very close to full).  Are you sure there's enough space one ONE drive for the large files?    An individual file won't be spanned across multiple drives ... so you could have enough free space in the array; but not enough free space on the drive that the write is attempted on => which would cause the failure you've noted.

 

 

Thanks for the advice. I will do as you say with the card. Saves me buying a second Sas breakout cable I did not think about the space on each drive. So if unraid runs out of space it doesn't discard the file and leaves it incomplete?

You say not to worry about moving stuff off the full drives to the newer drives but if I dont do this then my parity drive will still remain close to capacity. So wont this still keep the array going slowly?

You say not to worry about moving stuff off the full drives to the newer drives but if I dont do this then my parity drive will still remain close to capacity. So wont this still keep the array going slowly?

 

No, parity drive works different way. Its always as full as your biggest data drive. Add a new data drive, parity will be ok.

 

Remember you should not add a data drive bigger than your parity drive (but you can change parity first with a bigger one and move the old drive from parity to data)

 

 

I understand that but the parity drive will still be over 95% full which I am told to avoid?

I understand that but the parity drive will still be over 95% full which I am told to avoid?

There is NO file system on a parity drive so FULL does not apply.

Ok. Still I thought it was a case of the drive physically having data stored. Thanks for clearing up.

Technically, the parity drive is ALWAYS 100% full ==> not with any file system, but EVERY bit on the drive is used to store the longitudinal parity across all of the other drives.    But as noted already, it is NOT part of the file system.