On 4/8/21 11:43 AM, Nicolas Kovacs wrote:
# yum install cloud-utils-growpart # lsblk # growpart -v /dev/sda 3 # resize2fs /dev/sda3 Now here's my question (finally): is there any risk involved in this sort of operation? Or can it be performed on a production system without having to worry about data loss?
Risk from a Virtual Machine perspective or just generally? One of the many operations I do often with VMs is "mess" with disks treating them as logical devices means I can add storage later, easy, when needed. In most cases I don't take the system down at all. "It just works".
But there are always risks. If you're doing this manually, typos can bring down your system. Another part of your risk is using partitions. Partions, particular the "system" drive where rootfs is, can act oddly on Linux when it's live. It's not rare that you find the kernel refusing to do a "partprobe" on /dev/sda - which means you need a reboot for the kernel to see the new size of a partition. Next, your partition stuff is very limited - compared to so many other things you have in CentOS you should really avoid using partitions for anything - well, perhaps but that's about it.
I use LVM on all my systems. To expand a system I simply add a new virtual disk, expand the VG, and then expand the filesystem using "lvexpand -r". It's painless and there are no risks of conflicts. LVM allows me to remove the disk later if need be - ie. the first disk size you added was 50GB but you realize a few months later that you calculated wrong as should have added 500GB. LVM allows you to add a new disk of 500GB, move everything from the old disk to the new, and then you can remove the new one - all without taking down the file system!
It also comes with snapshot features for persistent backups. So at a risk of sounding like a broken record, don't use partitions. If risk is what you're focused on, there's a lot more risk using plain partitions vs. volume management.
-- Regards Peter Larsen _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx https://lists.centos.org/mailman/listinfo/centos
