# [Solved] Partitiontype 83 vs fd

## snilsson

I have a raid 5 setup and was thinking of replcing the disks with larger ones. When planning what to do I realized that the disks where partitions with partitiontype 83 (Linux). Obviously that is at least ok, I am not letting the kernel automount them anyway. 

But would it be better to use partitiontype fd (Linux raid auto) instead? 

If so can I change the type without major risk/problem?Last edited by snilsson on Fri Feb 05, 2010 2:31 pm; edited 1 time in total

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## eccerr0r

It's ok to change it as far as I know, it's just a flag in the partition table and it appears that it's not used when scanning for md disks - I've done this in the past on partitions I forgot to mark as autodetect.  If it works, don't change it.  It's not necessary, mdadm will read superblocks anyway.

If you want to have it autodetect in the future you might want to change it.

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## cyrillic

"type fd" partitions are needed if you want your rootfs to be on the array, and you don't use an initrd to assemble the array.

Since your rootfs is not on the array, the partition type does not matter.

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## snilsson

Thanks for the advises, I will leave it at 83 then.

So just to check, the basic procedure of replacing the disks is to add the larger ones one by one and resync the array for each. Then when the HW is in place I can resize the raid partitions or should I make the larger partition before adding the drive to the array.

Or maybe I should simply create a fresh new array with the new discs and just dd the data from the old to the new..

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