[Compass-ci] Re: [PATCH v3 compass-ci] doc: optimize os_mount.md

...

+The brief flow is as follow:

as follow => as follows

ok.

...

• 1. boot and request scheduler for job.
• 2. initrd stage:

•  - firstly, we need two logical volume:
  

•    ${src_lv} -- src logical volume:
  

•        - will never boot form this lv, just use it as a source data, and take a
  

form => from

ok

...

•          snapshot of it to get the real boot logical volume.
  

•        - srv_lv=/dev/mapper/os-${os}_${os_arch}_${os_version}_${timestamp}
  

srv_lv => src_lv

ok

-------- Thanks Yu Chuan

Thanks, Xijian

...

•    ${boot_lv} -- boot logical volume:
  

•        - will boot from this.
  

•        - boot_lv=/dev/mapper/os-${os}_${os_arch}_${os_version}
  

•  - if ${src_lv} not exists: create it, and rsync the rootfs from cluster nfs server.
  

•  - if ${boot_lv} exists: delete it
  

•  - create ${boot_lv} as the snapshot of ${src_lv}.
  

•  - switch root to ${boot_lv}.
  

• 3. boot the rootfs and execute the job.

+### persistent rootfs data

+When you need to persist the rootfs data of a job, and use it in the subsequent job(s), +two fields in `kernel_append_root` will help you: `save_root_partition`, `use_root_partition`.

+The brief flow is as follow:

as follow => as follows

...

• 1. boot and request scheduler for job.
• 2. initrd stage:

•  - firstly, we need two logical volume:
  

•    ${src_lv} -- src logical volume:
  

•    - if have ${use_root_partition}, src_lv=/dev/mapper/os-${os}_${os_arch}_${os_version}_${use_root_partition}
  

•    - if no   ${use_root_partition}, src_lv=/dev/mapper/os-${os}_${os_arch}_${os_version}_${timestamp}
  

•    ${boot_lv} -- boot logical volume:
  

•    - if have ${save_root_partition}, boot_lv=/dev/mapper/os-${os}_${os_arch}_${os_version}_${save_root_partition}
  

•    - if no   ${save_root_partition}, boot_lv=/dev/mapper/os-${os}_${os_arch}_${os_version}
  

•  - if ${src_lv} not exists:
  

•    - if have ${use_root_partition}, exit 1.
  

• • if no ${use_root_partition}, create ${src_lv}, and rsync the rootfs from cluster nfs server.

•  - if ${boot_lv} != ${src_lv}:
  

•    - if ${boot_lv} exists: delete it
  

•    - create ${boot_lv} as the snapshot of ${src_lv}.
  

•  - switch root to ${boot_lv}.
  

• 3. boot the rootfs and execute the job.

+Demo usage:

• • in 20210218, you submit a job-20210218.yaml, and you want to persist the rootfs data of

•  job-20210218.yaml so that it can be used by the subsequent jobs.
  

•  Then you need add the follow field in your job-20210218.yaml:
  

•      kernel_append_root: save_root_partition=zhangsan_local_for_iperf_20210218
  

• • in 20210219, you submit a job-20210219.yaml, and you want to use the rootfs data of

•  job-20210218.yaml.
  

•  Then you need add the follow field in your job-20210219.yaml:
  

•      kernel_append_root: use_root_partition=zhangsan_local_for_iperf_20210218
  

+Notes:

• • obviously, ${save_root_partition} and ${use_root_partition} must be the same, and unique.
• • you must 'save_root_partition' firstly, then you can 'use_root_partition'. otherwise, your job will fail.

+## work flow

+1. user submit job

• job fields:
• os: openeuler
• os_arch: aarch64
• os_version: 20.03
• os_mount: local
• kernel_append_root: use_root_partition=zhangsan_local_for_iperf_20210218 save_root_partition=zhangsan_local_for_iperf_20210219

2. scheduler return the ipxe_str to testbox

• dhcp
• initrd http://$%7Bhttp_server_ip%7D:$%7Bhttp_server_port%7D/os/openeuler/aarch64/20...
• initrd http://$%7Bhttp_server_ip%7D:$%7Bhttp_server_port%7D/os/openeuler/aarch64/20...
• imgargs vmlinux root=/dev/mapper/os-openeuler_aarch64_20.03 rootfs_src={nfs_server_ip}:os/openeuler/aarch64/20.03-iso-snapshots/{timestamp} initrd=initrd.lkp {kernel_append_root}
• boot

• dhcp
• initrd http://$%7Bhttp_server_ip%7D:$%7Bhttp_server_port%7D/os/openeuler/aarch64/20...
• kernel http://$%7Bhttp_server_ip%7D:$%7Bhttp_server_port%7D/os/openeuler/aarch64/20... root=/dev/mapper/os-openeuler_aarch64_20.03 rootfs_src=${nfs_server_ip}:os/openeuler/aarch64/20.03-iso-snapshots/${timestamp} initrd=initrd.lkp ${kernel_append_root}
• boot

3. dracut step of boot

• if have {use_root_partition}; then
• base_lv_name=openeuler_aarch64_20.03_{value_of_use_root_partition}
• lvdisplay /dev/mappaer/os-{base_lv_name} > /dev/null || exit 1
• if have {save_root_partition}; then

• boot_lv_name=openeuler_aarch64_20.03_{value_of_save_root_partition}
  

• if {save_root_partition} == {use_root_partition}; then
  

• 	boot from /dev/mappaer/os-{boot_lv_name}
  

• fi
  

• lvremove -f /dev/mappaer/os-{boot_lv_name}
  

• lvcreate /dev/mappaer/os-{boot_lv_name} from /dev/mappaer/os-{base_lv_name} || exit 1
  

• boot from /dev/mappaer/os-{boot_lv_name}
  

• else

• boot_lv_name=openeuler_aarch64_20.03_{value_of_use_root_partition}
  

• boot from /dev/mappaer/os-{boot_lv_name}
  

• fi
• else:
• base_lv_name=openeuler_aarch64_20.03_{timestamp}
• lvdisplay /dev/mappaer/os-{base_lv_name} > /dev/null || {

• # create logical volume
  

• lvcreate -L {root_partition_size} -n {base_lv_name} os || exit 1
  

• # rsync nfsroot to lvm:/dev/mapper/os-{base_lv_name}
  

• mount -t nfs {nfs_server_ip}:os/openeuler/aarch64/20.03-iso-snapshots/{timestamp} /mnt
  

• mkdir /mnt1 && mount /dev/mapper/os-{base_lv_name} /mnt1
  

• cp -a /mnt/. /mnt1/
  

• umount /mnt /mnt1
  

• # change premission of lvm:/dev/mapper/os-{base_lv_name} to readonly
  

• lvchange -p r /dev/mapper/os-{base_lv_name}
  

• }
• boot_lv_name=openeuler_aarch64_20.03
• if have {save_root_partition}; then

• boot_lv_name=openeuler_aarch64_20.03_{value_of_save_root_partition}
  

• fi
• lvremove -f /dev/mappaer/os-{boot_lv_name}
• lvcreate /dev/mappaer/os-{boot_lv_name} from /dev/mappaer/os-{base_lv_name} || exit 1
• boot from /dev/mappaer/os-{boot_lv_name}
• fi

• analysis_kernel_cmdline_params()
• {

•    for i in $(cat /proc/cmdline)
  

•    do
  

•            [ "$i" =~ "rootfs_src=" ] && export ROOTFS_SRC=${i#rootfs_src=}
  

•    done
  

•    [ -z "${ROOTFS_SRC}" ] && die "cannot find var in kernel cmdline params: rootfs_src"
  

•    export TIMESTAMP=$(basename ${ROOTFS_SRC})
  

• }
• rsync_src_lv()
• {

•    local src_lv=$1
  

•    lvdisplay ${src_lv} > /dev/null && return
  

•    # create logical volume
  

•    lvcreate --size 10G --name $(basename ${src_lv}) os || exit
  

•    # rsync nfsroot to ${src_lv}
  

•    mount -t nfs ${ROOTFS_SRC} /mnt
  

•    mkdir /mnt1 && mount ${src_lv} /mnt1
  

•    cp -a /mnt/. /mnt1/
  

•    umount /mnt /mnt1
  

•    # change permission of ${src_lv} to readonly
  

•    lvchange --permission r ${src_lv}
  

• }
• snapshot_boot_lv()
• {

•    local src_lv=$1
  

•    local boot_lv=$2
  

•    [ "$src_lv" == "$boot_lv" ] && return
  

•    lvremove --force ${boot_lv}
  

•    lvcreate --size 10G --name $(basename ${boot_lv}) --snapshot ${src_lv} || exit
  

• }
• main()
• {

•    analysis_kernel_cmdline_params
  

•    if [ -z "${use_root_partition}" ]; then
  

•            src_lv="/dev/mapper/os-openeuler_aarch64_20.03_${TIMESTAMP}"
  

•            rsync_src_lv ${src_lv}
  

•    else
  

•            src_lv="/dev/mapper/os-openeuler_aarch64_20.03_${use_root_partition}"
  

•            lvdisplay ${src_lv} > /dev/null || exit
  

•    fi
  

•    if [ -z "${save_root_partition}" ]; then
  

•            boot_lv="/dev/mapper/os-openeuler_aarch64_20.03"
  

•    else
  

•            boot_lv="/dev/mapper/os-openeuler_aarch64_20.03_${save_root_partition}"
  

•    fi
  

•    snapshot_boot_lv ${src_lv} ${boot_lv}
  

•    boot_from_boot_lv
  

• }
• main()

4. execute the job

-- 2.23.0