how to configure block size of container partition?

[Alibek]

For example:
have ocfs2 mounted volume as storage on proxmox.
ocfs2 volume have next blocksize

/sbin/tunefs.ocfs2 -Q 'blocksize: %B\nclustersize: %T\n' /dev/sdd1
blocksize: 4096
clustersize: 4096

and volume on barmetal storage and hdd/ssd have 512 or 4096 bytes blocksize.

After create container, created image have partition with blocksize: 512 bytes
That is not good for align and have penalties on write:
512 -> 4096 -> 512

fdisk -l /data1/images/100/vm-100-disk-1.raw

Disk /data1/images/100/vm-100-disk-1.raw: 8 GiB, 8589934592 bytes, 16777216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x9bf7d5ca

Device                               Boot Start      End  Sectors Size Id Type
/data1/images/100/vm-100-disk-1.raw1 *     2048 16775167 16773120   8G 83 Linux

or

fdisk -l /dev/mapper/vg01-vm--104--disk--1

Disk /dev/mapper/vg01-vm--104--disk--1: 50 GiB, 53687091200 bytes, 104857600 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

How to setup blocksize for containers on create?

 

[Richard]

For example:
have ocfs2 mounted volume as storage on proxmox.
ocfs2 volume have next blocksize

/sbin/tunefs.ocfs2 -Q 'blocksize: %B\nclustersize: %T\n' /dev/sdd1
blocksize: 4096
clustersize: 4096

and volume on barmetal storage and hdd/ssd have 512 or 4096 bytes blocksize.

After create container, created image have partition with blocksize: 512 bytes
That is not good for align and have penalties on write:
512 -> 4096 -> 512


How to setup blocksize for containers on create?

Partitioning of root-filesystem is not configurable.

You can mount any prepared partition as additional filesytem in a container's mountpoint by pct commant, e.g.

pct set 161 -mp1 /dev/sdc6,mp=/mnt/disk2

can be also a file, which has to be presented as loop device, e.g.:

losetup /dev/loop6 myfile
pct set 161 -mp2 /dev/loop6,mp=/mnt/disk3

For having your self-created root-filesystem device the following workaround should work (even it's not an officially supported method):


- create your own file (e.g. by making a filesystem with 4k blocks on it) which will contain the root-filesystem

- stop your container

- mount both the original container filesystem and the new one in the host system

- copy all files from the original fielesystem to the new one

- unmount both files

- overwrite the original file with the new file

That's it! You can start the container and it will now use the new filesystem (with e.g. 4k blocks).

 

[Alibek]

Thx! I known this method but this is wrong way for many times creating container from webui.
I think need field "Block size" in dialog "Create container" (feature request).

 

[Alibek]

Also be good if some default parameters may set per DC, per Pool, per Node.