RAID 5 - Performance Issues - Recommendations

[bobak2000]

Hi,
I've got a QNAP TS-419P II with 4x 2TB Hitachi Hard Disks.
I've been running the system for about 2 years with RAID5 set up and since moving to a new house I've been using it a lot more for storing files and running UPnP to watch video files.

The system is incredibly slow. It boots just fine and the OS itself is responsive but when copying to or from the NAS the files transfers are ridiculous. It was set up using a Powerline (200Mbps) which at my old house was running at 88Mbps and seemed ok. At the new place it was crawling to a halt so I replaced the powerline with a second Airport Express (Wireless Access Point/Extender). So the set is, CAT5e from the LAN port on the NAS to the Airport Express at 5GHz 802.11n to extend the network downstairs which is all 100/1000Mbps LAN. I've tested the network and the signal quality is good - its going about 5 metres realistically - and the wifi connects and extends at 270Mbps.

When I copy from or two the NAS it transfers at about 3.4Mbps... which is truly terrible. Most the files are between 1Gb and 10Gb is size and frankly I spend half my time waiting around for it.
I decided that the Wifi must be the weak spot, so to test for this I plugged the NAS with CAT5e directly into a Gigabit switch, then my Macbook into the 2nd port of the same Gigabit switch. No other devices involved at this point. I copied a 1.5Gb file from the NAS to my Mac with Wifi turned off and only Gigabit LAN.... 3.5Mbps copy speed.

I had no idea these QNAPs were so bad at RAID5... either that or something else is terribly wrong.

I'm copying all of my files off of the NAS and I'm going to wipe it and get rid of RAID5 unless anyone can convince me otherwise.

Can I please ask for advice - is everyone's RAID5 set up this slow? If I ditch RAID5, what's the best alternative for better performance with some redundancy?

Thanks.
Bob

[Don]

I doubt it is the raid. Are you sure the connections are at connecting at gigabit speed and not 100mb? Did you disconnect the wifi connection when connecting to the switch? What firmware are you running?

[bobak2000]

I'm running the latest firmware, I forget the exact number but it was checked yesterday.
I am connecting using a CAT5e to a gigabit switch, so yes - however even if I was connecting at 100Mbps I'd expect more than 3.5Mbps transfers, All Wifi completely disconnected yes.

If it's not the RAID, what do you suggest it is?

I think it's justs poor RAID support at the moment. Network is fine, everything else seems fine, it's literally only read/write to and from disks. What is weird though is when I connect a USB disk to the front and try copying off of that, I only get 10Mbps... Are these things really that slow or is something wrong?

[Don]

Saying current firmware means nothing. Using a cat5e cable doesn't mean you a connecting at 1gb. Please list the firmware version. Check the connection status of all devices to see if they are connecting at 1gb.

What is the network configuration (auto/forced, DHCP, trunk mode, protocols enabled, etc).
How are you doing the transfer?
What is CPU utilization during a transfer?
What else is installed and running?

etc, etc, etc

[bobak2000]

wow, ok sure.

The firmware is 3.7.3 Build 801 - it was on the previous build (don't ask me to specify - still 3.7, not sure after that) and it was running the same performance then too.

I am using Static Routing with only Ethernet 1 enabled, no port trunking or bonding.
I am connecting to a Netgear 5 port 10/100/1000 Switch using a CAT5e standard RJ45 cable from the NAS to the switch, then an identical cable to the macbook's 10/100/1000 Ethernet port.
No DHCP, TCP/IP is used, no intelligent routing protocols like EIGRP or RIP or BGP as it's LAN only.

Connection status' are fine, copying to and from other devices appear to be a LOT quicker than the NAS.

The NAS is a TS-419P Turbo NAS - 1.2GHz Marvell with 512Mb RAM.
4x 2TB Hitachi Hard Disks - not sure which models - in RAID 5.

What is the network configuration (auto/forced, DHCP, trunk mode, protocols enabled, etc).
-Auto Negotiation, Static TCP/IP, no Trunk Mode - single connection.

How are you doing the transfer?
- Normally copying over 802.11n 5GHz Wifi, but for testing I was using a wired 1Gb Netgear Switch with Cat5e cables.

What is CPU utilization during a transfer?
- CPU utilization appears to be around 50-60% but does spike occasionally up to 100%

What else is installed and running?
Twonky Media Server is running, iTunes server running, FTP and Bit-torrent, but Bit-torrent has been turned off for this testing.

From my windows Laptop I am achieving 2.5MB/s read speed over FTP.
From my Macbook I am achieving around 3.4-3.6MB/s read speed over Samba.

Everything is in the same Subnet, Network has been tested and updated and appears to be running fine at about 270Mb/s access speed over Wifi or 100/1000Mb/s Wired, depending where you plug in.

Don't know what else you'd want to know.
As far as I'm concerned the NAS is simply not performing. I could be wrong. It's very slow indeed.

One other note is that 99% of the time it is clicking away, it's noisy and therefore is upstairs in the spare room. It never seems to go to sleep or be quiet. It's usually on for about 16 hours a day then powers down at night.

[bobak2000]

Put it this way, downloading a file off of the internet is about 4 times faster than off of the NAS. Internet comes down at about 12-14MB/s over a 100Mb/s connection...

[ncvbit]

So if you unplug the NAS from your network and hook a laptop directly up to it, and try to copy/move files between your laptop and the NAS, what kind of speeds do you see? If you see expected speeds then you know something is happening on your network to slow things down. If the speeds are slow then check the CPU/Memory usage on the NAS to help troubleshoot why the NAS is performing slow.

[bobak2000]

I don't have a crossover cable to hand, so I've unplugged the NAS from the network, created a very small LAN at 1Gb/s using literally 2 ethernet cables and a gigabit switch. I am seeing read speeds of 3.5MB/s...
CPU utilisation was generally around 50% as was RAM usage.

[Don]

Connection status' are fine, copying to and from other devices appear to be a LOT quicker than the NAS.

So you have gone into the NAS web gui and confirmed that it is connecting at 1000mb?

[P3R]

I don't have a crossover cable to hand...

You shouldn't need a crossover cable as the Qnap does automatic MDI/MDIX.

What connection speed is reported by the Qnap in the speed column at the System Administration, Network page?

Do you have any network errors reported in the error column of the System Status, System Information page?

You can by the way see the exact disk model used on the Disk Management, Volume Mangement page.

[bobak2000]

Right, Disks are:

Hitachi HDS722020ALA330JKAO

No disk errors reported.

LAN says it's connecting at 100Mb/s - but this is probably because I have reverted back to Wifi now.

Forgive me if I'm wrong here - but 100Mb/s LAN - even if it's not running at 1Gb/s at the moment - should have a greater throughput than 3.5MB/s right?

[bobak2000]

Ok, I was convinced it was just very poor RAID performance, but I'm going to disable anything that I don't use daily and remove all applications etc and see how it runs.

ie/ Only iTunes server and DLNA, Apple and Microsoft Networking enabled.

[2000wolf]

Another reason for slow speed are full drives. How much free drive space left?

[bobak2000]

about 4.5TB are free - so not full drives.

I disabled all the Apps last night. I deleted any QPKGs and stopped all additional services other than iTunes Server and DLNA. I left AFP, Samba and Microsoft Networking running and tried some Read transfers over the WiFi (270Mb/s 802.11n - which has been checked) and the speed did increase... to about 5-5.1MB/s. I still think this is painfully slow. A 1.1Gb file takes about 5 minutes to copy still. CPU and Memory utilisation were both about 50% max.

[ncvbit]

100Mb/s = 12.5MB/s - so the Max you can expect is 12.5MB on that connection. if you have the qnap plugged into a 1Gb switch then there is a problem with auto negotiation, and you need to manually select 1Gb on both the Qnap and the switch interface. Otherwise your switch might knock you down to half duplex or I have even seen where one end is sending at 100Mb and the other thinks it's 1Gb and lots and lots of errors along the way. So check both endpoints.

-Brandon