I realized I was still on receiving the daily digest format last night, so I have probably screwed up the threading on this now. If you cc me directly maybe I can maintain the future threading.
Ok, looking at Parted it looks like the resize (or resizepart) command will be what I will need. But that doesn't appear to help recognize the expanded disk, so I think I need something before that. That is what I thought the echo 1 > rescan would do for me.
I will look more into fdisk to understand the capabilities there. I am going to take advantage of the holiday weekend in a few days to take care of this so I am trying to understand all of the options available to me before diving into the task.
In response to Gordon also, I did rescan the drive as suggested and got the same results; no such file or directory. So then I did a search for the rescan file to see where it was present. Found it in a few locations, but this one looks to be the one that I would want to try.
/sys/devices/pci0000:00/0000:00:01.1/host1/target1:0:0/1:0:0:0/
The rescan file was also located in just: /sys/bus/pci but don't know if that would do the job for the specific device.
Thanks for everyone's input. Very helpful. More suggestions are welcome while I am still reading up on options.
Jeff
Date: Wed, 1 Sep 2021 13:15:37 -0400 From: Stephen John Smoogensmooge@gmail.com To: CentOS mailing listcentos@centos.org Subject: Re: [CentOS] Troubles expanding file system. Message-ID: CANnLRdhhRkMagTcZ+eqALoteYcXD26nMrHzv7L9F1A35jGS=3g@mail.gmail.com Content-Type: text/plain; charset="UTF-8"
On Wed, 1 Sept 2021 at 12:42, Jeff Boycejboyce@meridianenv.com wrote:
Greetings -
I have tried posting this four times now, from two different emailaddresses (on the 25th, 27th, 30th, and 31st) and it never appeared. I don't see it in the archives, so it appears to be getting dropped in transition for some reason. I am not getting messages from the email system saying it is undeliverable, or is bounced; I am sending as plain text, not HTML, I stripped off my signature. If this makes it through, someone please give me a clue why the others might not have. But that is not as important as the real issue that I am trying to get addressed below. Thanks for any assistance.
I have a Dell PowerEdge server with a CentOS KVM host (Earth) withone CentOS guest (Sequoia) that I am trying to expand the partition and filesystem on. I have LVM logical volumes on the host system (Earth), which are used as devices/partitions on the guest system (Sequoia). In this particular situation I have successfully extended the logical volume (lv_SeqEco) on Earth from 500GB to 700GB.
- Checking the disk information (lsblk) on Earth shows that the
logical volume (lv_SeqEco) is now listed as 700GB.
- Checking disk information (lsblk) on Sequoia shows that the disk
/dev/vde is still listed as 500GB, and partition /dev/vde1 where the mount point /ecosystem is located is also listed as 500GB.
- I had tried using the resize2fs command to expand the filesystem on
/dev/vde1, but it returned with the result that there was nothing to do. Which makes sense now after I checked the disk information, since /dev/vde on Sequoia has not increased from 500GB to 700GB.
Thanks for the long list of items of what you have done. In Fedora Infrastructure, we used this method to resize images in the past https://pagure.io/infra-docs/blob/main/f/docs/sysadmin-guide/sops/guestdisk....
The guest system usually needs to have the `fdisk` , `gdisk` or `parted` commands rerun to resize the disk to its new size.
- On previous occasions when I have done this task, I would just start
GParted on Sequoia and use the GUI to expand the partition and filesystem. A real quick and simple solution.
- The problem I have now is that the VGA adapter on my server has died
and I have no graphical output to the attached monitor, nor to the iDrac console display. So I am stuck doing this entirely by the command line while logged into the system remotely.
- I suspect that I need to rescan the devices on Sequoia so that it
recognizes the increased space that has been allocated from the extended the logical volume. But when I did that (command below) it came back with a no such file or directory.
echo 1 > /sys/class/block/vde1/device/rescan
Not sure that would do anything.
- This server is being retired in the next few months, but I need this
additional space prior to migrating to the new system. Can someone give me some guidance on what I am missing in this sequence?
Let me know if I haven't been clear enough in the explanation of my systems and objective. Thanks.
On Thu, Sep 2, 2021 at 7:16 PM Jeff Boyce jboyce@meridianenv.com wrote:
- I suspect that I need to rescan the devices on Sequoia so that it
recognizes the increased space that has been allocated from the extended the logical volume. But when I did that (command below) it came back with a no such file or directory.
echo 1 > /sys/class/block/vde1/device/rescan
Not sure that would do anything.
What are the CentOS versions of your host and guest? As far as I know, virtio disks have never supported rescan from inside the guest and so there isn't the corresponding "rescan" special file. I found this old, but interesting thread: https://forum.proxmox.com/threads/extend-rescan-virtio-disk-in-guest-vm.7989...
Can you confirm your host libvirt version and your guest kernel are ok with what is referred? In case you could try with the qemu monitor command.
See also here for a reference of possible qemu monitor commands: https://qemu-project.gitlab.io/qemu/interop/qemu-qmp-ref.html
And here for consideration regarding RH EL 6 host: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/htm...
Also here you find reference of command to issue, but somehow the syntax changes depending on components' versions: https://www.humblec.com/is-it-possible-to-do-online-resizing-of-guest-block-...
HIH, Gianluca
Hi Jeff,
I realized I was still on receiving the daily digest format last night, so I have probably screwed up the threading on this now. If you cc me directly maybe I can maintain the future threading.
Ok, looking at Parted it looks like the resize (or resizepart) command will be what I will need. But that doesn't appear to help recognize the expanded disk, so I think I need something before that. That is what I thought the echo 1 > rescan would do for me.
I'm not sure what your current state is but I'd like to point out what I usually do to online resize disks on KVM hosts/guests.
After expanding the disk image/logical volume, let the quest know it has changed. To do so, run like this on the host:
virsh blockresize db01 /var/lib/libvirt/images/db01.var.img 7516192768B
or
virsh blockresize db01 vdb 7516192768B
Note: I'm using bytes (B) as unit to make very sure it's correct!
After doing so, you should see that disk size has changed on the guest, in syslog or with dmesg.
Now you can modify partition tables or pvresize. After that, resize the fillesystems with resize2fs or xfs_growfs.
That's all possible while the guest is online with one exception outlined below.
There is one thing that I couldn't find a solution for no matter what I tried: When the root/boot disk of the guest is being resized, it's not possible to modify and reread the new partition table without reboot.
Regards, Simon
On 9/2/2021 10:28 PM, Simon Matter wrote:
There is one thing that I couldn't find a solution for no matter what I tried: When the root/boot disk of the guest is being resized, it's not possible to modify and reread the new partition table without reboot.
I'm curious to know if this works for you. Suppose /dev/sda is the boot disk. Determine the highest number primary partition in use on the drive. Let's say it's 3.
# growpart /dev/sda 3
In addition, you might try
# printf "F\n" | parted ---pretend-input-tty -l
I have these in an Ansible playbook for creating CentOS 7 and Ubuntu Focal VMs. They require cloud-int (for growpart) and gdisk. Note: growpart doesn't work if the highest partition is not a primary partition, i.e., greater than 4.
Jack
On 9/2/2021 10:28 PM, Simon Matter wrote:
There is one thing that I couldn't find a solution for no matter what I tried: When the root/boot disk of the guest is being resized, it's not possible to modify and reread the new partition table without reboot.
I'm curious to know if this works for you. Suppose /dev/sda is the boot disk. Determine the highest number primary partition in use on the drive. Let's say it's 3.
# growpart /dev/sda 3
In addition, you might try
# printf "F\n" | parted ---pretend-input-tty -l
I have these in an Ansible playbook for creating CentOS 7 and Ubuntu Focal VMs. They require cloud-int (for growpart) and gdisk. Note: growpart doesn't work if the highest partition is not a primary partition, i.e., greater than 4.
I think the problem in my case was that EL6 didn't support this. From growpart man page:
"this requires kernel support and 'partx --update'"
Maybe it works for newer systems but didn't work when I last had to do it on EL6.
Simon
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Gianluca Cecchi -
Jack Bailey -
Jeff Boyce -
Simon Matter