Re: [gentoo-user] RAID 1 install guide?

[Kerin Millar]

On 05/09/2013 07:13, J. Roeleveld wrote:
> On Thu, September 5, 2013 05:04, James wrote:
>> Hello,
>>
>> What would folks recommend as a Gentoo
>> installation guide for a 2 disk Raid 1
>> installation? My previous attempts all failed
>> to trying to follow (integrate info from)
>> a myriad-malaise of old docs.
>
> I would start with the Raid+LVM Quick install guide:
> http://www.gentoo.org/doc/en/gentoo-x86+raid+lvm2-quickinstall.xml
>
>> It seems much of the documentation for such is
>> deprecated, with large disk, newer file systems
>> (ZFS vs ext4 vs ?) UUID, GPT mdadm,  etc etc.
>
> Depending on the size of the disk, fdisk or gdisk needs to be used.
> Filesystems, in my opinion, matter only for the data intended to be put on.
>
> For raid-management, I use mdadm. (Using the linux kernel software raid)
> If you have a REAL hardware raid card, I would recommend using that.
> (Cheap and/or onboard "raid" is generally slower then the software raid
> implementation in the kernel and the added bonus of being able to recover
> the raid using any other linux installation helps.
>
>> File system that is best for a Raid 1 workstation?
>
> I use Raid0 (striping) on my workstations with LVM and, mostly, ext4
> filesystems. The performance is sufficient for my needs.
> All my important data is stored on a NAS with hardware Raid-6, so I don't
> care if I loose the data on the workstations.
>
>> File system that is best for a Raid 1
>> (casual usage) web server ?
>
> Whichever filesystem would be best if you don't use Raid.
> Raid1 means all data is duplicated, from a performance P.O.V., it is not a
> good option. Not sure if distributed reads are implemented yet in the
> kernel.

They are. It's perfectly good for performance, provided the array is of 
insufficient magnitude to encounter a bottleneck pertaining to 
controller/bus bandwidth.

--Kerin