There are two types of storage:
Ephemeral Storage - By default users do not have access to any form of persistent storage. The disks associated with VMs are ephemeral dissapearing when a VM is terminated.
Persistent Storage - persistent means that the storage resource is always available regardless of the state of a running instance.
Openstack support three types of persistent storage:
Object storage is implemented in OpenStack by the Object Storage service (swift). Users access binary objects through a REST API. If your intended users need to archive or manage large datasets, you should provide them with Object Storage service.
The Block Storage service supports multiple back ends in the form of drivers, most drivers allow the instance to have direct access to the underlying storage hardware’s block device. This helps increase the overall read/write IO.
Because these volumes are persistent, they can be detached from one instance and re-attached to another instance and the data remains intact.
Howto
$ openstack volume create --helpEx:
$ openstack volume create --size 100 \
--description "Test 100Gb" my_100_vol
$ openstack volume show my_100_vol -c id
+-------+--------------------------------------+
| Field | Value |
+-------+--------------------------------------+
| id | ce56c6ba-f87a-4cfa-9b1d-b77b782022dd |
+-------+--------------------------------------+$ openstack volume list -c Name -c Status -c Size | grep available
| test_ | available | 100 |
| vol_10 | available | 8 |
$ openstack server list -C Name -c Status -c Networks --user xxxxxx
+--------------+--------+---------------------------------------+
| Name | Status | Networks |
+--------------+--------+---------------------------------------+
| my_test2 | ACTIVE | demo-net=192.168.1.3 |
+--------------+--------+---------------------------------------+$ openstack server add volume --device /dev/vdb \
7a5d8a54-150d-4b3e-a815-7405e9c76d59 eec10c75-689c-433c-8762-d67208184d55
$ openstack server show my_test2 -c 'volumes_attached'
+------------------+-------------------------------------------+
| Field | Value |
+------------------+-------------------------------------------+
| volumes_attached | id='eec10c75-689c-433c-8762-d67208184d55' |
+------------------+-------------------------------------------+Get a volume ID
$ openstack volume list -c ID -c Name| grep my_100_vol
| ce56c6ba-f87a-4cfa-9b1d-b77b782022dd | my_100_vol |$ openstack server create --flavor m1.medium \
--image Fedora-27 --nic net-id=$OS_NET \
--block-device-mapping vdb=ce56c6ba-f87a-4cfa-9b1d-b77b782022dd \
--security-group default --key-name jhondoe-key \
test_my_100
+-----------------------------+-----------------------+
| Field | Value |
+-----------------------------+-----------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | |
| OS-EXT-STS:power_state | NOSTATE |
| OS-EXT-STS:task_state | scheduling |
| OS-EXT-STS:vm_state | building |
| OS-SRV-USG:launched_at | None |
| OS-SRV-USG:terminated_at | None |
| accessIPv4 | |
| accessIPv6 | |
| addresses | |
| adminPass | vJh9X4PKtam4 |
| config_drive | |
| created | 2018-04-07T17:29:17Z |
| flavor | m1.medium (3) |
| hostId | |
| name | test_my_100 |
| progress | 0 |
| volumes_attached | |
+-----------------------------+-----------------------+$ openstack volume show my_100_vol -c status
+--------+--------+
| Field | Value |
+--------+--------+
| status | in-use |
+--------+--------+In the recently created vm ( !!! )
$sudo su -
root> fdisk /dev/vdb
...
...
...
...
Created a new partition 1 of type 'Linux' and of size 100 GiB.
...
/dev/vdb1 2048 209715199 209713152 100G 83 Linux
...
Writing superblocks and filesystem accounting information: doneNote: In a very large volume you must use "parted" instead "fdisk"
Create a file system
$ mkfs.xfs /dev/vdb1Mount the new file system
$ mkdir /mnt/vol1
$ mount /dev/vdb1 /mnt/vol1Ex:
$ df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 2.0G 0 2.0G 0% /dev
tmpfs 2.0G 0 2.0G 0% /dev/shm
tmpfs 2.0G 496K 2.0G 1% /run
tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup
/dev/vda1 40G 791M 37G 3% /
tmpfs 396M 0 396M 0% /run/user/1000
/dev/vdb1 98G 61M 93G 1% /mnt/vol1When you recreate a new the vm, you only do
For resize a file system you must in the order
Umount the file system
$ sudo umount /mnt
$ exitDetach the volume
$ openstack server remove volume 83232561-0be8-4b33-8a14-3b5bd834ee87 b811b277-8918-4e66-8e7c-1ee976d49a63
$ openstack volume list
+--------------------------------------+------------+-----------+------+
| ID | Name | Status | Size |
+--------------------------------------+------------+-----------+------+
| 39f400b5-e224-427e-b86a-64ea1d29c21f | to_delete3 | available | 20 |
| c1395e36-ccb0-4e5b-ae50-877ac1a7c90c | to_delete2 | available | 500 |
| 2f111391-8352-4799-aa6b-ffe96f8dc02b | to_delete | available | 500 |
| 6d6e65b7-3148-42f7-94ae-48051632641f | vol_jcc_03 | available | 500 |
| 60b46b5c-668a-42fd-9ba4-29ee13d2d20f | vol_jcc_02 | available | 500 |
| a4c79fc5-8042-4517-b9d4-3fc1e92c22f5 | vol_jcc_00 | available | 500 |
| b811b277-8918-4e66-8e7c-1ee976d49a63 | 50_vol_jcc | available | 50 |
| cacb3aa3-90fe-4c34-b5ce-98d1e89da449 | 10_vol_jcc | available | 10 |
+--------------------------------------+------------+-----------+------+Resize the volume
$ openstack volume set b811b277-8918-4e66-8e7c-1ee976d49a63 --size 100
$ openstack volume list
+--------------------------------------+------------+-----------+------+
| ID | Name | Status | Size |
+--------------------------------------+------------+-----------+------+
| 39f400b5-e224-427e-b86a-64ea1d29c21f | to_delete3 | available | 20 |
| c1395e36-ccb0-4e5b-ae50-877ac1a7c90c | to_delete2 | available | 500 |
| 2f111391-8352-4799-aa6b-ffe96f8dc02b | to_delete | available | 500 |
| 6d6e65b7-3148-42f7-94ae-48051632641f | vol_jcc_03 | available | 500 |
| 60b46b5c-668a-42fd-9ba4-29ee13d2d20f | vol_jcc_02 | available | 500 |
| a4c79fc5-8042-4517-b9d4-3fc1e92c22f5 | vol_jcc_00 | available | 500 |
| b811b277-8918-4e66-8e7c-1ee976d49a63 | 50_vol_jcc | available | 100 |
| cacb3aa3-90fe-4c34-b5ce-98d1e89da449 | 10_vol_jcc | available | 10 |
+--------------------------------------+------------+-----------+------+Atach the volume
$ openstack server add volume --device /dev/vdb \
83232561-0be8-4b33-8a14-3b5bd834ee87 b811b277-8918-4e66-8e7c-1ee976d49a63
$ ssh -i ~/.ssh/os_jhondoe.pem centos@134.158.21.40
$ sudo su -
$ mount /dev/vdb1 /mnt$ df -h | grep mnt
/dev/vdb1 50G 11G 40G 22% /mnt
$ umount /mnt
$ parted /dev/vdb
GNU Parted 3.1
Using /dev/vdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
Error: The backup GPT table is not at the end of the disk, as it should be. This might mean that another operating system believes
the disk is smaller. Fix, by moving the backup to the end (and removing the old backup)?
Fix/Ignore/Cancel? Fix
Warning: Not all of the space available to /dev/vdb appears to be used, you can fix the GPT to use all of the space (an extra
104857600 blocks) or continue with the current setting?
Fix/Ignore? Fix
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 53.7GB 53.7GB xfs primary
(parted) p
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 53.7GB 53.7GB xfs primary
(parted) resizepart 1 100%
(parted) p
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 107GB 107GB xfs primary
(parted) q $ sudo mount /dev/vdb1 /mnt $ df -h | grep mnt
/dev/vdb1 50G 11G 40G 22% /mnt$ sudo xfs_growfs /dev/vdb1
...
...
data blocks changed from 13106688 to 26214139
$ df -h | grep mnt
/dev/vdb1 100G 11G 90G 11% /mntThe Shared File Systems service is persistent storage and can be mounted to any number of client machines. It can also be detached from one instance and attached to another instance without data loss. During this process the data are safe unless the Shared File Systems service itself is changed or removed.
It represents an allocation of a persistent, readable, and writable filesystems. Compute instances or clients outside access these filesystems.
You ask for a share space and provide him with one ore more ip addresses to mount it.
$ manila create NFS 4 --name test5_jccAllow read only access to a snapshot for a given IP or range.
$ manila access-allow test5_jcc ip 134.158.21.33 --access-level roIt must give you a shared mounting point.
$ manila show test5_jcc | grep path
path = 134.158.20.112:/var/lib/manila/mnt/share-120a99ae-d7cb-4e35-b23263aafc7f1821 After that you can mount it in one or more vms.
$ sudo mkdir -f /mnt
$ sudo mount -vt nfs4 134.158.20.112:/var/lib/manila/mnt/share-120a99ae-d7cb-4e35-b232-63aafc7f1821 /mnt
mount.nfs4: timeout set for Tue Jun 30 09:34:59 2020
mount.nfs4: trying text-based options 'vers=4.1,addr=134.158.20.112,clientaddr=192.168.2.24'
$ mount | grep mnt
134.158.20.112:/var/lib/manila/mnt/share-120a99ae-d7cb-4e35-b232-63aafc7f1821 on /mnt type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=192.168.2.24,local_lock=none,addr=134.158.20.112)Check your share
$ sudo ls > /mnt/toto
-bash: /mnt/toto: Read-only file system
$ sudo umount /mntIts posible to mount the share in a external host. The openstack admin must be notified to prepare the right ACL set giving access to shared zone.