Where to start...RAID...LVM...

[lip]

Hi,
I'm totally new to the linux world. I am starting this journey wanting to have a NAS solution.
I tried freenas but because of some issues with my internal lan chipset, I started looking elsewhere and found Amahi.

So...my setup is as follows:
- 1 20gig hard drive (IDE)
- 3 1TB hard drives (SATAII)
- AMD cpu with gigabyte mobo(doesn't matter what the models are)
- 2 gig memory

I want to run Fedora and Amahi off of the 20 gig drive and have the 3 remaining drives in a software RAID.

I'm not sure how to setup this. I have chosen to only use the 20 gig during the installation...is this correct? How do I go about setting up a RAID install. I've searched and found mdadm but no real easy guides for a complete newbie(I just installed this today and coming from a windows background, I'm pretty lost).

So far I like Amahi but I think it's missing some NAS functionality (data transfer monitoring, RAID setup,etc...)
Any suggestions?

Thanks.
LIP

[cpg]

personally, i don't like LVM. i feel like a disk failure could render an lvm volume hard to recover. now, on top of raid, that's another matter.

i just "surf" disks. i buy a bigger one after a while and transition my old content to it. i keep the old drive for a bit as a backup. but that doesn't help you i'm also old school, so i have not tried raid yet in hardware (or software for that matter).

we have not focused too much on disk/volume management. we rely on the base hardware platform and distribution for that. one day we will get there, in particular after apps are working solidly across the board. we don't try to be good at everything, so if there is one app that is really good at that, we should put it to good use.

our shares management is top of class. i have heard is really some of the best there is.

as far as raid, i think the best is hardware raid. if you have that, i'd stick to it.

if not, then mdadm is the only thing i am aware of. one good guide is the linuxhomenetworking.com guide. however it's far from plug and play.

i am not a raid expert, though. we have some experts in raid in the community, so hopefully they will chime in!

[moredruid]

I don't have any experience with software RAID on Linux, but there's a lot of info here: http://linux-raid.osdl.org/index.php/Linux_Raid and here: http://tldp.org/HOWTO/Software-RAID-HOWTO.html. The last one is a bit outdated but maybe still informative.

LVM on RAID seems to be different than normal LVM, this is also explained somewhere on the site of the first link.

@cpg: migrating from one LV to another is no different than migrating from disk to disk. LVM is just more flexible, giving you options to resize the filesystem online (yes I know you can mount 2 partitions in 1 mount point, but LVM abstracts this 1 layer lower)

[lip]

Thanks guys.
I'm not fixed to RAID as even sites like smallnetworkbuilder recommend against it for most homes.
I'll probably just go with another external drive that I'll backup to periodically but definitely it would help if you guys automated some of this a bit more.

However, I guess my question is related to fedora and linux in general.

When I installed Fedora at first, it ended up making my 1 big "space" rather than individual drives. I guess this is LVM.
Can someone recommend how to parition with anaconda during installation with ext3?
I have the following:

1- 20 gig drive for fedora/amahi installation
3- 1TB drives for storage



Thanks in advance.
Good work.
LIP

[moredruid]

an automated "backup" is currently being tested I think.

anyway, what I did was the following (my drives are pretty much the same setup as yours):
install Fedora on 1st drive (20GB) and make sensible choices on the partition sizes (you don't need a large homedrive unless you want to keep stuff from others).
in anaconda, create a phyisical volume first (create LVM), choosing your 3 drives (if this doesn't work, just choose 1 disk for the physical volume, you can extend the volumegroup etc. later online but make sure you note down the device names and sizes of your 3rd & 4th drive - probably this will be /dev/sdc & /dev/sdd )
you'll need to create a volume group (mine is called "vgdata", default is VolGroup00 I think) and a logical volume (mine is called "lvdata", default is LogVol00) and make sure the mountpoint is "/var/hda"

write the changes to disk and finish the fedora install
before you install Amahi you resize your LVM as described here

when you're finished resizing, unmount /var/hda and run an fsck on it:
root@host # fsck /dev/vgdata/lvdata
this will take a while, but it will ensure your disks are at least in good order before you go and install anything on it

Then proceed with installing amahi with the hda-install <yourcode> command

good luck!

[relrobber]

the only hands-on experience i have w/ RAID is the hardware towers at work, but if u wanna try it out, i'd suggest RAID5. that would give u the speed advantage of striping and the redundancy of mirrors. the only drawback is that u lose a whole drive's worth of capacity. (3 1TB drives = 2TB of storage.)

[gjc1000]

When I first started to think about a server, I went through the raid or no raid, hardware raid or software raid,WHS, freenas, ready nas ect. Went crazy for a few month on the issue, really crazy. There are whole forums dedicated to this debate, but In the end, and after I discovered Amahi, I decided not to go with raid of any kind I set mine up like this:

160 gb disk for Operating system/HDA
1Tb disk setup as /var/hda1
1Tb disk setup as /var/hda2
1Tb disk setup as /var/hda3
1Tb disk setup as /var/hda4
My server is used for media and such, not business. This works well for me, and if a disk craps out, I just have to get a new one and put the movies back on.
I have been toying around with getting another 160gb drive and mirroring (I think it's raid 0 or 1) or do daily full backups. So if that disk fails, my operating system/HDA will be backed up and up to date. But, I have been playing with all the new features that the Devs keep rolling out and haven't had the time. Well that and learning linux too

[lip]

Thanks guys...
gjc1000:
Would you mind outlining exactly what your settings were when you setup fedora on the hard drives for each drive(160g - how much was boot, how much was swap, root, etc...what did you do for the other drives)....
I've got fedora on a 20 gig and 3 1TB drives...right now everything is seen as one(LVM) but I will re-install this later.

My plan is not to go with raid either...I'll end up buying some backup esata external drives and store this offsite every month or so...just in case there is theft or fire or damage...I don't care about re-installing everything though....

Thanks in advance,
LIP

[gjc1000]

160 gb hardrive with a 2 gb swap file using ext3 file system
The 1 tb drives us the xfs file system
FYI, 4 gb of memory

[relrobber]

wishing i had backed up about now...day 4 of trying to recover my corrupted storage drive from my Amahi box. <sigh> at least the wife didn't argue when i immediately went out and got a 1TB external for backups.