did i set up RAID-1 correctly....

[code:1]root@host:~# sfdisk -d /dev/sda > partitions.txt
root@host:~# cat partitions.txt

partition table of /dev/sda

unit: sectors

/dev/sda1 : start = 63, size=488392002, Id= 5
/dev/sda2 : start = 0, size= 0, Id= 0
/dev/sda3 : start = 0, size= 0, Id= 0
/dev/sda4 : start = 0, size= 0, Id= 0
/dev/sda5 : start = 126, size= 995904, Id=82
/dev/sda6 : start = 996093, size= 9767457, Id=83
/dev/sda7 : start = 10763613, size= 9767457, Id=83
/dev/sda8 : start = 20531133, size=467860932, Id=83

root@host:~# sfdisk /dev/sdb < partitions.txt


Then I went into Webmin > hardware > Linux RAID

> Create RAID device of level > mirrored (RAID1)

selected all partitions in /dev/sdb and clicked create

…Is there anything else I should do? did I do it all wrong?

[code:1]RAID Device

RAID device options
Device file /dev/md0
RAID level Mirrored (RAID1)
Filesystem status Active but not mounted
Usable size 497856 blocks (486.19 MB«»)
Persistent superblock? Yes
Chunk size Default
RAID status clean
Partitions in RAID SCSI device B partition 5
SCSI device B partition 6
SCSI device B partition 7
SCSI device B partition 8 [/code:1]

thanks in advance!


Post edited by: aeisecurity, at: 2008/05/19 05:37<br><br>Post edited by: aeisecurity, at: 2008/05/19 06:44

Hey Rich,

I’m not sure I see the point of combining a bunch of partitions on the same disk into a RAID array? There’s no redundancy provided by doing so, and as you might note the size of your new RAID partition is limited to the smallest partition. I’m pretty sure this is not what you intended.

If you’re trying to make use of a whole single sdb disk, you just want to make a whole single disk partition.

If you’re trying to make a mirror device of device sda, you’ll need to boot up from a bootable CD (it’s possible to make a “live” RAID mirror, but I don’t recommend it, and I would strongly recommend you make backups immediately before), and mirror all of the contents of each individual partition on sda onto sdb…and then connect them up as a RAID 1 mirror. If the system doesn’t have anything interesting on it yet, creating RAID partitions during installation of Red Hat and CentOS is insanely easy (as well as LVM volumes)…but once up and running Webmin is one of the better UIs for the task.

You’ll want to have a look at the Software RAID HOWTO for a general overview of the topic:


And, of course, the mdadm man page is a good reference.

Finally, the Webmin documentation on the subject:


Thank you for the advice :slight_smile: