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

Re: "rock solid" motherboard

> Using a Linux kernel shows two drives even when RAID is
> enabled because the drivers bypass the BIOS. The drivers
> just try to enable the disk controllers directly. That
> problem can be found in the Kernel.org bugzilla.

Most "sata raid" controllers aren't raid controllers. They're just normal sata 
controllers with a fancy bios. The do not have any hardware raid 

> The motherboard disk controller chips are mostly useful
> for enlarging disks or mirroring only. Two 74G disks can
> be made into one 148G disk only that won't be faster than
> one 74G disk(maybe only slightly faster). The mirroring
> works good because two disks can be driven as fast as one
> disk. 

This is just plain wrong. I suggest you go and read some good documentation on 
the properties of different RAID formats. Generally speaking RAID0 doubles 
throughput for large writes as data is striped across both volumes, and has 
seek times the same as a single drive. RAID1 (mirroring) usually gives 
similar throughput to a single drive for large transfers, and a good driver 
can reduce average seek times by reading data from whichever drive head is 

> The Linux kernel does not now support any of the 
> motherboard chips capable of native RAID mode in the BIOS.

Not true. Read http://linux.yyz.us/sata/faq-sata-raid.html.
Most (maybe all?) of the proprietary raid formats are supported by the dmraid 

> Both Debian and Ubuntu installer or
> distribution kernels are best replaced with a custom kernel
> compiled for your own equipment and setup for best results.

Using a custom kernel is only a good idea if you already know what you are 
doing, or absolutely need something not included in your distro kernel. Most 
users are better sticking with the provided kernels as they then get the 
security patching and testing done by the Debian kernel teams.


Reply to: