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orkid1989

Poor vm disk performance

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I've been using unraid for a while to run a game server through a windows 10 vm. It has worked pretty well with a few tweaks. But all of a sudden over the weekend it seems to be extremely slow so I pulled up task manager and it shows 100% disk usage (everything else appears fine) but a fluctuating max of about 10mbps. It will bounce to 30ish but only for a brief second and then back to single digits. So I looked at unraid and it's not checking parity or anything else that I can see and it says the same numbers as task manager. Shouldn't the read/write speeds be substantially higher?

 

I doubt it is the drive because it is on a 6 month old 2tb iron wolf. With a 6tb iron wolf parity drive and a 6tb iron wolf array drive which are about 3 months old. They are installed in a lenovo s30 thinkstation and connected to the 3 sata2 ports. Could the ports on the board be failing? It also has a xeon 1620v2 with all cpu's allocated to the vm (tried 2 and 3 core but performance was even worse). Any ideas what the problem may be? And will it help to buy a raid card? Considering a LSI 9207-8i

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Edited by orkid1989
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Why not put the vdisk on your cache pool.  Array devices are by nature very slow compared to the cache drive(s) unless you enable turbo write mode

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Well I only have 620gb available in the cache pool so the vm will use up the entire thing. Also afraid to lose the data transfering it to the cache

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I dont see turbo write mode. Only "auto", "read/modify/write", and "reconstruct write".

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Just now, orkid1989 said:

I dont see turbo write mode. Only "auto", "read/modify/write", and "reconstruct write".

Turbo mode is another name for the 'reconstruct write' option.

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12 minutes ago, orkid1989 said:

o ok. is their any downside to 'reconstruct write'?

All array disks will spin up and stay spun up as long as there are any writes.

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1 hour ago, jonathanm said:

All array disks will spin up and stay spun up as long as there are any writes.

So pretty much higher power consumption? And how about the ca automatic turbo plug in?

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also @Squid mentioned adding it to the cache pool, could i just move the 2tb drive to the pool instead of copying it to the the ssd's?

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44 minutes ago, orkid1989 said:

also @Squid mentioned adding it to the cache pool, could i just move the 2tb drive to the pool instead of copying it to the the ssd's?

No. The array disks are individually formatted with a single device file system, the cache pool is a BTRFS RAID volume. If you move the 2TB to the cache pool, two main things will happen. First, all the data on the 2TB will be erased, permanently deleting your VM, second, the performance of the cache pool will be reduced by probably a factor of 10.

 

You don't want to mix vastly different performing devices in the cache pool, as it will slow down to the least performing member.

 

I do need to ask, what on earth are you doing in a VM that requires that much space? All my VM's are program and OS only, all the data is on the user shares in the array. My largest VM is about 120GB.

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It is to run dedicated servers. 1 game alone takes up over 100gb with the DLC. Maybe I should get another ssd and transfer the vm to the cache drive?

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how fast should the average read and write speed be on array drives? using sata 2 if it matters

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