Messages in this thread | | | Date | Wed, 17 Sep 1997 12:09:08 -0400 | From | Chris Wedgwood <> | Subject | Re: 2.0.29 and maximum number of user. |
| |
Date: Mon, 15 Sep 1997 09:26:25 +0100 (GMT/BST) From: Mike Jagdis <mike@roan.co.uk> To: Chris Wedgwood <chris@cyphercom.com> Subject: Re: 2.0.29 and maximum number of user.
On Thu, 11 Sep 1997, Chris Wedgwood wrote:
> I would think a mirror large enough to require raid0 (for speed) is > probably large enough that you would really want raid5...
Depends. Raid 5 is less useful if you have heavy write loads or do not have a write back cache big enough to avoid saturating under peak write loads. Raid 0, 1 and 5 are all useful in their place.
Agreed. But I was talking about the specific case of an ftp/www mirror. I don't operate one of these, so I don't speak from experience, but I would guess reads are maybe one hundred times more prevalent than writes for this type of use.
raid0 has better write (and read) performance, but a large array could conveiable have a high failure rate. (MTBF per drive / no. of drives).
raid1 is a tad expensive when you have 10+GB of data or so. (Actually, maybe this was once true, but disk is cheap nowdays).
-Chris
| |