On Wed, 2006-03-01 at 13:40 +0100, Marton Gabor wrote: > Hi! > > I'm going to recieve 4x250Gb SATA disks to our new server, and my first > idea was to make 2xRAID1 and then make 1xRAID0 out of the RAID1 arrays > using Linux software raid so that I have our data mirrored and still I > can use 500Gb storage space and handle it as one big "disk". > So my questions would be: > - could someone give me a good howto? Sorry, but I have never had > the chance to make a RAID array before and I have no experience and > Google doesn't seem to be helpful in this case. > - do I need to make a /boot partition which is not part of any > arrays or will grub boot from raid1+0? grub can boot from raid1, raid0+1 will need a (small) boot partition.
With 4 disks you could also build a raid5 with little overhead, takes a tad more cpu and gives you 750G capacity (or 500 with one hotspare) short howto: Take a livecd with mdadm on it or install an extra harddisk for initial configuration. Now you can partition the disks with fdisk. I'd create a small boot partition and swap partitions (say, 500M per disk) plus a big partition for "everything". Set the partition type to FD (?) (raid autodetect) Maybe you want a smarter setup - use 10G for /, 10G for /var and the rest for /home or so. That way you have 10G / raid1, 10G /var raid1 and 240G for /home raid1+0 mdadm is very easy to use. mdadm --create /dev/md0 /dev/sda1 /dev/sdb1 --level=1 --chunk=128 would create a raid1 (level parameter) with two disks and a chunk size of 128kB so just create the devices you need from that - you can delete or change at any time during the process. Now you have /dev/md* devices, just format them with the filesystem of you choice and be happy :-) if they are type raid autodetect they'll be enabled during boot Have fun, Patrick -- Stand still, and let the rest of the universe move
signature.asc
Description: This is a digitally signed message part
