How to increase write performance on ReadyNAS

[Chewbacca]

You may notice that ReadyNAS may seem a bit slow on writes using the default configuration. There is a way to increase that write performance significantly.

First, you will need a Uninterruptable Power Supply (UPS) with a USB connection. It doesn't have to be a large one, just big enough to protect the data in case of the power failure. A 250VA unit will be more than adaquate. Plug the ReadyNAS in to the power plug in on the UPS, making sure you plug in to the protected outlet. Next you need to connect the USB connection from the UPS to USB connector on ReadyNAS. Now turn it on.

Once the UPS is connected, ReadyNAS will automatically turn on the Write Cache option on drives. For further increase of writes, turn off the full journaling option. You can do that by clicking on the System button. If you don't see the System button, make sure you click on the Advanced Control button first. Then click on the Performance tab on the top. Then check the second option, Disable full data journalling for RAID 5 volumes, and click apply.

You should now see a large improvement on write performance of ReadyNAS.

[Dominion]

If using write-cache and/or disabling journalling and power was to fail, what would be the likely consequences?

[yoh-dah]

If powerfails and you've enabled writecache, data in the disk writecache can be lost if not written out to the disk platters. Chance is slim, but there's a risk that you can lose up to 32MB of unwritten data if you have 4 disks with 8MB writecache each.

If powerfails and you disable journaling, upon boot, NAS will need to run a full filesystem check, which depending on volume size and usage, can be several minutes to hours.

[Dominion]

Thank you.

[drewpc]

If I use the ReadyNAS 1000 in a datacenter environment (where all AC power is on a UPS), do I have to have a UPS with a USB connection in order to get write-caching to work?

[Han Solo]

No, you can turn on write caching without a USB UPS connected.

[cbm]

Hi all

I have a ReadyNas X6 on order, what is the expected sustained write performance improvement in turning on write cacheing ? 1 /5 /10 Mbps ?

Or is this feature only available on the ReadyNas 600?

I would like to understand the improvment to see if the increase can justify buying a UPS to enable the functionality (more kit to upset the misses ).

I would like to use the X6 to be the location that my Media Centre PC uses to record TV to - that way it can easily be accessed from other PC's, the throughput of that needs to exceed 4 Mbps sustained.

Kind regards

CBM

[yoh-dah]

Hi all

I have a ReadyNas X6 on order, what is the expected sustained write performance improvement in turning on write cacheing ? 1 /5 /10 Mbps ?

Or is this feature only available on the ReadyNas 600?

I would like to understand the improvment to see if the increase can justify buying a UPS to enable the functionality (more kit to upset the misses ).

I would like to use the X6 to be the location that my Media Centre PC uses to record TV to - that way it can easily be accessed from other PC's, the throughput of that needs to exceed 4 Mbps sustained.

Kind regards

CBM

Sustained sequential write performance for X6 is about 11-12 MB/sec (megabytes per second) without jumbo frames. With jumbo frames, it can bump up to about 16-17 MB/sec depending on your switch and PC. With the X6, it's highly recommended to run with the write cache enabled. Your performance will suffer a lot if disabled, so do get a UPS. They're actually pretty cheap these days...

[cbm]

Hi, thanks for the update, APC USB UPS on the way.

Out of interest is the sustained write of the ReadyNas 600 similar to the X6 or much higher

CBM

[yoh-dah]

Hi, thanks for the update, APC USB UPS on the way.

Out of interest is the sustained write of the ReadyNas 600 similar to the X6 or much higher

CBM

The X6 is faster, by about 2MB/sec.

[JReble]

I'm only getting about 4.5 MB/sec write speed out of my new X6. I've got a ups with usb port attached, write cache enabled, and I'm using gigabit network cards with a Netgear 5 port Gigabit Ethernet Switch model GS605. Read speeds appear to be satisfactory, but my write speeds are terribly low. What would you suggest?

[yoh-dah]

I'm only getting about 4.5 MB/sec write speed out of my new X6. I've got a ups with usb port attached, write cache enabled, and I'm using gigabit network cards with a Netgear 5 port Gigabit Ethernet Switch model GS605. Read speeds appear to be satisfactory, but my write speeds are terribly low. What would you suggest?

Try disabling the journal. But we do recommend you have a UPS to avoid lengthy filesystem check after powerfail.

[JReble]

It's already disabled. From previous posts I'm expecting 2 to 3 times this write speed.

[yoh-dah]

It's already disabled. From previous posts I'm expecting 2 to 3 times this write speed.

Do a quick IOMeter test (see http://www.infrant.com/forum/viewtopic.php?t=265 ) and let me know what you get for read and write.

[JReble]

Ok, ran the tests as indicated....

Write results:

Write IOps: 32.062291

MBps: 8.015573

Transactions Per Second: 32.062291

Avg Response Time: 31.183962



Read Results:

Read IOps: 102.222964

MBps: 25.55574

Transactions per Second: 102.222964

Avg. Response Time: 9.776898



Seems to be writing too slow.