Questions regarding mdadm

[Godi]

Hello

I am about to upgrade my current setup with 6x1tb in a software raid5 using mdadm, to a 3x2tb software raid5 still with mdadm.

My problem lies in, that currently the raid is setup with sda/sdb/sdc/sdd/sde/sdf, and when i plug in the new hdds i assume (havent bought them yet) they will get sdg/sdh/sdi, which will be the new raid.

This is all good, question is when i unplug my old raid, will the new hdds be "renamed" into sda/sdb/sdc and will that break the raid?

Can I change hdds device name in the new raid without breaking it? Or will it maybe figure it out automatically

/Christian

[ptkobe]

Hello

I am about to upgrade my current setup with 6x1tb in a software raid5 using mdadm, to a 3x2tb software raid5 still with mdadm.

My problem lies in, that currently the raid is setup with sda/sdb/sdc/sdd/sde/sdf, and when i plug in the new hdds i assume (havent bought them yet) they will get sdg/sdh/sdi, which will be the new raid.

This is all good, question is when i unplug my old raid, will the new hdds be "renamed" into sda/sdb/sdc and will that break the raid?

Can I change hdds device name in the new raid without breaking it? Or will it maybe figure it out automatically

/Christian

AFAIK, mdadm uses UUID and superblock info, it doesn't care if it is /dev/sdi or /dev/sdc

My experience is with ubuntu-server, I will not put my hands on the fire here
So, please be careful and try to have a contingency plan at hand.

If you are careful and don't make a mess, you'll be able to mount your old raid again, get functional, and try another go.

There are other issues, like grub loader and /etc/fstab, that may get confused (but not if it is set with UUID or refer to the mdadm array).

There's also a grub file that relates to the disks order. See
$ cat /boot/grub/device.map
but I don't think you'll need it if you will just be installing a new OS in the new raid.

Regards
Luis