[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Software RAID 5 or something else?

aragonx dcsnow com wrote:
Hello all,

I had a drive failure a few months back so I decided it was time to rework
my home server's storage.

Now I have 5 750GB SATA dives and now I need some advice on how to set
things up.

My original idea was to put them in a RAID 5 configuration.  This sounded
good until I started researching RAID controller cards.  It looks like it
will cost me $520 to get a good PCI-E card (3Ware 8 port).  I don't think
I want to spend that much if I don't have to.

My goals are two fold.

1) I want to get some redundancy in case of a drive failure.

2) I want to increase my performance.  I have benchmarked my read and
write performance to and from this server.  Using Samba, I seem to be able
to get about 50Mb/sec reads and 40Mb/sec writes.  I am on a gig network
and would like to be able to max out the cards (90Mb/sec is what I get at

So, the question is, what should I do?

1)  Bite the bullet and get the hardware RAID controller.  Will this give
me the performance I want?

2)  Go with a software RAID 5.  Will I lose performance with this
configuration?  If I use this but only get modest performance gains, that
would be acceptable.

3)  Go with some other software RAID level.

Any help would be appreciated.

Will Y.

If you understand that there is really no such thing as hardware based RAID.

There is 'dedicated hardware' based RAID, which is software based RAID on a card that does nothing else but RAID.

Most of these RAID cards have a small, slow, CPU, and relatively slow RAM modules to run the RAID software.

So considering that, what do you gain from dedicated hardware for RAID? You get a commercially supported RAID software and hardware package, and you get to unload a bit of CPU from the main system.

Considering that the CPU on the card at max performance is probably 1/3 of a core from a modern CPU, then that is not really much of a savings.

The real consideration for RAID 5 is survival. In either situation you have to have a spare drive, and you have to consider availability of new drives to match them in the future.

Good Luck!

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]