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View Full Version : [ubuntu] Server 64 mdadm Raid 5 set up issue



RPMouton
September 5th, 2009, 12:42 AM
Hey Folks,

OK, I have searched and experimented but haven't been able to make mdadm work to set up a raid 5 array.

I have the OS installed on dev/sda and installed 3 more drives sdb, sdc and sdd

I have tried issuing the mdadm command with the drives partitioned and formatted, not partitioned and partitioned and not formatted. In all cases I get the following :


roger@Phubuntu:/dev$ sudo mdadm --create /dev/md0 --level=raid5 --force /dev/sdb1 /dev/sdc1 /dev/sdd1
mdadm: no raid-disks specified.What am I doing wrong?

Thanks in advance,

tgrimley
September 6th, 2009, 12:42 AM
Hey Folks,

OK, I have searched and experimented but haven't been able to make mdadm work to set up a raid 5 array.

I have the OS installed on dev/sda and installed 3 more drives sdb, sdc and sdd

I have tried issuing the mdadm command with the drives partitioned and formatted, not partitioned and partitioned and not formatted. In all cases I get the following :


roger@Phubuntu:/dev$ sudo mdadm --create /dev/md0 --level=raid5 --force /dev/sdb1 /dev/sdc1 /dev/sdd1
mdadm: no raid-disks specified.What am I doing wrong?

Thanks in advance,



You dont have the command formatted correctly. Also, you'll DEFINITELY want to partition the drive so you know it is easier to determine it has a RAID partition on it.

then, you should be doing


roger@Phubuntu:/dev$ sudo mdadm --create /dev/md0 --level=raid5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1

RPMouton
September 6th, 2009, 10:55 PM
You dont have the command formatted correctly. Also, you'll DEFINITELY want to partition the drive so you know it is easier to determine it has a RAID partition on it.

then, you should be doing


roger@Phubuntu:/dev$ sudo mdadm --create /dev/md0 --level=raid5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1


Thanks much,

I will try this out when I get back in town and report back.

regards,