Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I've set up a Raid 5 system at home for the first time. I've added 3 disks into the pc, and parted them all in 1 partition of 8G, and 1 partition of the remaining 492G then I made 2 raid volumes with each partition

Mounted the 16G as swap, and the other one as the system disk.

This worked like a charm, then I added a 4rd disk to the array did the same thing (parting in 2 partitions, and added both to the previously defined raid5 arrays) (mdadm --add /dev/sdd1 etc...)

Then I did the mdadm --grow /dev/md0 --raid-devices=4 command (ref: http://zackreed.me/articles/48-adding-an-extra-disk-to-an-mdadm-array)

Both arrays got rebuild, but they're not using the new size. and the performance of my system dropped terribly.

I've tried booting in recovery mode, and doing the resize2fs /dev/md1 command, but I keep getting "read only disk" stuff as issue.

How can I fix this? because normal boot will keep my main disk in "busy" status, and I've not dared doing a forced unmount

What can I do to get my performance back up?

If any more information is needed, do tell, and I'll supply what I can. Thx in advance.

share|improve this question

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.