Comment 1 for bug 346461

Try running some basic speed tests like the following:

sudo hdparm -t /dev/your_drive
&
sudo hdparm -T /dev/your_drive

You might have to do some sysctl and ioctl hackery.

I've been running Ubuntu 'hardy' with a generic 500gb eSATA connection
and was running into very low transfer speeds with this drive. Come to
find out, DMA wasn't being enabled for some reason.

I have not tried this with any of the recent Nexenta buillds, so your
results might be different.

I hope this helps a little.

John

On 3/21/09, Max <email address hidden> wrote:
> Public bug reported:
>
> Disk write performance is extremely low on Nexenta 2.0 beta 2, compared
> to other operating systems running on the same hardware.
>
>
> Block write performance as measured by bonnie++:
>
> Nexenta 2.0 beta 2: 4 mb/sec
> FreeBSD 7.1 (ZFS): 58 mb/sec
> Opensolaris preview 2009.06 b109: 74 mb/sec
>
>
> Disk drive: Mtron Pro 7000 SSD
> Disk controller: tried both connecting the drive to the mainboard (Nvidia
> MCP55 chipset) as well as an Areca 1200 pci-e SATA card.
>
> Also created a forum post, but have received no replies so far:
> http://www.nexenta.com/corp/index.php?option=com_fireboard&Itemid=44&func=view&catid=11&id=755
>
> ** Affects: nexenta
> Importance: Undecided
> Status: New
>
> --
> Extremely low disk write performance
> https://bugs.launchpad.net/bugs/346461
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>