Raid Card controller for FC System
agraham at g-b.net
Tue Mar 25 17:18:30 UTC 2008
Most modern motherboards will all you to have 4 or 6 SATA drives
connected, so the cheap solution is to use Linux software raid, that's
the best bang for your buck you're gonna get :), on the other hand, if
you're interested in higher spec try this:
$325 - http://www.3ware.com/products/serial_ata2-9650.asp
Fedora 8 kernel includes drivers for this card.
This card has lots of very nice features, firstly the drives can be
configured as JBOD, so it can act as a simple controller allowing you to
use Linux Software Raid, it has 256MB write cache, You can buy a BBU
separately as shown here:
The nice thing about the above, is it does not sit on the same card - it
uses an extender cable + a dummy slot (high or low profile).
Performance on these cards are excellent, "but only if configured
correctly" - Use the right file system for the job.
The website states "delivering over 800MB/s RAID 6 reads and 600MB/s
RAID 6 writes.", but you will not achieve this with 4 disks. you will
probably achieve 2.5x your normal read/write performance, so if you're
drives give you 100MB/s you can except around 250MB/s read using Raid 5.
i.e. this card reads & writes to all drives in parallel - which is what
you expect from hardware raid.
I have the 12 Port version on my desktop and have 8x1TB drives in a Raid
5 array and I get 624MB/s+ writing and 750MB/s reading (both on a file
size of 100G+).
Note: This card should not be confused with the old 955xx cards, they're
not so good.
Other nice features are hot-swap and auto-rebuild, nice web interface as
well a a useful (but binary) command line interface - which allows
monitoring IOPs and setting lots of lower level functions (such as
drive-level cache etc..), it also has an A/V mode, when enabled it will
not start verifying your disks in the middle of a job.
Make sure you have the same drives with the same firmware version, as
this can cause performance problems. The monitoring tools will allow you
spot a slow / problematic disk easily before they become a problem.
There is also a nice cabling solution - i.e. 1 to 4 breakout cable included.
BTW: This card is PCI Express x8 but will operate in slower or faster
slots (mine is x16)
If possible use 3GB/s drives (SATA II), they'll give you the edge - I
gain 50MB/s when this is enabled using 8 drives :)
Most smart-mon-tools functions work with the card as expected, in
addition some, but not all power functions work, so you "can" issue
"sdparm -C stop /dev/sdc" to spin down an entire array for example.
It took me a long time to get the performance I expected from this card,
mostly due to Raid alignment and using XFS file system. - Ext3 is a dog
on Raid 5 :(
edwardspl at ita.org.mo wrote:
> Dear All,
> Which model / type of ATA Raid card controller is good for work with
> New FC System ?
> Would you please recommend ?
> Thank for your help !
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