Performance advice?

Hi, I'm back :twisted:

I've been reading a lot in the forum about how you guys that are experts consider acceptable read/write speeds to be in the 100 MB/s range. I'm not getting anywhere near that. Reads average from 55 to 75 MB/s, writes are in the 40s. Admittedly, I'm doing this on the cheap, and this may be the best I can do with what I have, but I wanted to see if you could advise me on ways to speed up my system.

Here's what I have. My OMV is a Dell Optiplex 755 with a Core 2 Duo E6550 and 4 GB RAM. System drive is an 80 GB Maxtor ATA 100 on a serillel adapter, storage is 3 x 2 TB Toshiba SATA-3 HDs in an OMV RAID 5. Onboard NIC is an Intel 82566DM-2 gigabit adapter. Router is a new Netgear R6250 gigabit, cables are all Cat5e. My main CPU is a Core 2 Duo 8400 with 3 GB RAM, one of those onboard Realtek nics that get so much love around here, and Win XPSP2.

Possible issues: 1) storage drives are SATA-3, mobo bus they are on is SATA-2. This shouldn't be an issue, SATA-2 still has a theoretical transfer rate of around 475 MB/s. The drives themselves are new and bench well, according to my research on them. 2) Kernel unhappiness. I installed the backport, and it DID improve performance (prior writes sometimes in the teens), but not to where I'd like it. 3) NIC - this particular Intel chip seems to have had issues with the Linux 2.6x kernel, to the point where some folks mentioned it could actually be damaged by that kernel. As I said, the backport was better, but.... 4) Drive or RAID configuration. It took a couple hours to set it up and format - I didn't think it was supposed to take that long. I installed the supportinfo plugin, and it says, ominously,

fdisk -l
--------------------------
Disk /dev/md127 doesn't contain a valid partition table

but it works and is identified as a RAID volume with 2 shares and a total capacity of 3.64 TB.

Any ideas? I'm not opposed to buying a PCI-e or PCI nic to slap in the OMV, if you think it will help.

Oh, by the way, my router has a ReadyNas feature because of it's USB 3.0 (4.8 Gb/s) port. It's pretty cool, really, you just plug in a USB HD and it automagically configures it as a network storage device and tells your computer it's there. The same utility I used to benchmark OMV says my USB 3.0 HD gets reads/writes averaging 20 MB/s this way, so it's still not as good as a dedicated NAS, even a crippled one like mine.

UUID? is this it?

# definitions of existing MD arrays
ARRAY /dev/md/raid metadata=1.2 name=openmediavault:raid UUID=3fe8c30b:1ab0b409:ac326ae2:8e3dd14a

If so, I will run it tomorrow. Thank you for your help!

Maybe not as long as you think I think we need to look elsewhere.

10000+0 records in
10000+0 records out
10485760000 bytes (10 GB) copied, 31.7179 s, 331 MB/s

What next?

I just connected my main directly to my OMV. If anything, performance was worse. I did this to see if my router was the problem, apparently it's not.

New NIC? Or NICs?

Zitat von "ryecoaaron"

Well, that doesn't make much sense. What size of files are you transferring?

It didn't make much sense to me. Usually, 400 MB.

I've got a few more things to try and am visiting a friend this weekend. Don't go away, if you don't hear from me for a few days don't think I've given up.

I'll try to keep this brief and fail miserably. I've tried a lot of stuff, more than I can remember to tell about here, but I'm not sure how much I trust how I'm doing it or the software I'm using. Results vary widely. Any comments would be welcome.

First: donh, thanks for the link. On my setup, disabling flow control resulted in a decrease in network speed, so I went back to enabled.

Ryecoaaron – Although I'm very happy with a raid speed of 331 MB/s, I have to ask, is RAID 5 a force multiplier? Each of my drives is supposed to bench in the 180 MB/s range which, as I understand it, was near the top end for hard drives 8 months ago.

Tekkbebe – I don't have a variety of gigabit routers/switches, just the new Netgear R6250.

Things I've tried:

1) Direct connection. Nope. Performance decreased. I used a cat 7 cable?
2) Disconnecting the 100 Mb/s legs from the network. No difference. I would expect that a smart router would be able to handle this, anyway.
3) Updating drivers in main cpu. Slight performance gain.
4) Disabling bandwidth hogging apps. Like antivirus and Carbonite. I allow very few programs to run on their own, and my system is not laden with crapware, Windows excluded. Slight performance increase.
5) Consolidating shares. I started off with 2 shares, each reporting the full size of my RAID. I thought, maybe, this would cause bandwidth sharing??? Anyway, I created a 3rd share, copied the contents of the other 2 shares into it. Then, I deleted the 2 original shares. No performance difference. HOWEVER, prior space usage was 450+ GB, now over 900 GB. I would REALLY like someone to comment on this.
6) Installed “backport” kernel. Slight performance increase, seems more stable.
7) Increasing MTU on main from 1500 to 4000. This resulted in a 30% gain on 2 tests, the most effective thing I did. Am I on to something? I tried to set the other components to this MTU – router max is 1500, OMV loses network at 4000, requiring an omv-firstaid.

Software used. I took WastlJ's (opportunistic) advice (be careful what you ask for :lol: :)) and increased file size to 1 GB. This had no real effect until I increased the MTU on the main

1) NAStester 1.7. Mentioned other places on this forum. Original reads usually in the 50's, writes in the 40's. After MTU, writes around 70, reads in the low 70's.
2) CrystalDiskMark. Original reads/writes in the mid 70's, after MTU reads in the high 70's, writes in the low 90's.
3) LAN Speed Test lite. Original reads in the 50's, original writes in the 20's, After MTU, reads in the mid 70's, writes around 60.

As always, any comments or advice are appreciated. I should have a running Linux system up within a couple weeks, I'll let you know how it does with NFS