Verify Stratis Filesystem UUID

[drckeefe]

There are a number of ways that a Stratis filesystem UUID could be changed, erased, or corrupted outside of Stratis’ control. Should Stratis be aware of this kind of change and if so, what should be done about it?

In this example the a filesystem is created and then wiped, however from Stratis’ point of view the filesystem still exists and displays the UUID. The UUID is stored in the MDV and could be used for verification.

stratis pool create p1 /dev/loop0
 
stratis fs create p1 fs1
 
mkdir /fs1
 
mount /dev/stratis/p1/fs1 /fs1
 
[root@ci~]# df -lh
Filesystem                                                                                       Size  Used Avail Use% Mounted on
devtmpfs                                                                                         869M     0  869M   0% /dev
tmpfs                                                                                            888M     0  888M   0% /dev/shm
tmpfs                                                                                            356M  9.5M  346M   3% /run
/dev/vda1                                                                                         20G  2.0G   19G  10% /
tmpfs                                                                                            178M     0  178M   0% /run/user/0
tmpfs                                                                                            1.0M     0  1.0M   0% /run/stratisd/keyfiles
/dev/mapper/stratis-1-377c6813ac5947c0b2d0d91e65e5642b-thin-fs-232c3a2f36da45a89532592570838ece  1.0T  7.2G 1017G   1% /fs1
 
[root@ci~]# stratis pool
Name                   Total Physical   Properties                                   UUID
p1     10 GiB / 583.65 MiB / 9.43 GiB      ~Ca,~Cr   377c6813-ac59-47c0-b2d0-d91e65e5642b
 
[root@ci~]# stratis fs
Pool Name   Name   Used      Created             Device                UUID                                
p1          fs1    546 MiB   Jan 17 2022 16:49   /dev/stratis/p1/fs1   232c3a2f-36da-45a8-9532-592570838ece
 
[root@ci~]# blkid
/dev/vda1: UUID="b7392ae2-037b-442a-b489-5b1f6ed9cb7c" BLOCK_SIZE="512" TYPE="xfs" PARTUUID="460985b7-01"
/dev/loop1: UUID="9550b846-ccc0-4276-b123-c46046a05a95" POOL_UUID="377c6813-ac59-47c0-b2d0-d91e65e5642b" BLOCKDEV_SECTORS="20971520" BLOCKDEV_INITTIME="1642456188" TYPE="stratis"
/dev/mapper/stratis-1-377c6813ac5947c0b2d0d91e65e5642b-thin-fs-232c3a2f36da45a89532592570838ece: UUID="232c3a2f-36da-45a8-9532-592570838ece" BLOCK_SIZE="512" TYPE="xfs"
 
[root@ci~# umount /fs1
[root@ci~]# wipefs -a /dev/stratis/p1/fs1
/dev/stratis/p1/fs1: 4 bytes were erased at offset 0x00000000 (xfs): 58 46 53 42
 
[root@ci~]# blkid
/dev/vda1: UUID="b7392ae2-037b-442a-b489-5b1f6ed9cb7c" BLOCK_SIZE="512" TYPE="xfs" PARTUUID="460985b7-01"
/dev/loop1: UUID="9550b846-ccc0-4276-b123-c46046a05a95" POOL_UUID="377c6813-ac59-47c0-b2d0-d91e65e5642b" BLOCKDEV_SECTORS="20971520" BLOCKDEV_INITTIME="1642456188" TYPE="stratis"
 
[root@ci~]# stratis pool
Name                   Total Physical   Properties                                   UUID
p1     10 GiB / 583.65 MiB / 9.43 GiB      ~Ca,~Cr   377c6813-ac59-47c0-b2d0-d91e65e5642b
 
[root@ci~]# stratis fs
Pool Name   Name   Used      Created             Device                UUID                                
p1          fs1    546 MiB   Jan 17 2022 16:49   /dev/stratis/p1/fs1   232c3a2f-36da-45a8-9532-592570838ece
 
[root@localhost scripts]# reboot
--- vm started ---
(manually start loop0 again)
 
[root@ci~]# stratis pool
Name                   Total Physical   Properties                                   UUID
p1     10 GiB / 583.65 MiB / 9.43 GiB      ~Ca,~Cr   377c6813-ac59-47c0-b2d0-d91e65e5642b
 
[root@ci~]# stratis fs
Pool Name   Name   Used      Created             Device                UUID                                
p1          fs1    546 MiB   Jan 17 2022 16:49   /dev/stratis/p1/fs1   232c3a2f-36da-45a8-9532-592570838ece
[root@ci~]# blkid
/dev/loop0: UUID="9550b846-ccc0-4276-b123-c46046a05a95" POOL_UUID="377c6813-ac59-47c0-b2d0-d91e65e5642b" BLOCKDEV_SECTORS="20971520" BLOCKDEV_INITTIME="1642456188" TYPE="stratis"
/dev/vda1: UUID="b7392ae2-037b-442a-b489-5b1f6ed9cb7c" BLOCK_SIZE="512" TYPE="xfs" PARTUUID="460985b7-01"
 
[root@ci~]# ls -trlh /dev/mapper
total 0
crw-------. 1 root root 10, 236 Jan 17 16:54 control
lrwxrwxrwx. 1 root root       7 Jan 17 17:04 stratis-1-private-377c6813ac5947c0b2d0d91e65e5642b-physical-originsub -> ../dm-0
lrwxrwxrwx. 1 root root       7 Jan 17 17:04 stratis-1-private-377c6813ac5947c0b2d0d91e65e5642b-flex-thinmeta -> ../dm-1
lrwxrwxrwx. 1 root root       7 Jan 17 17:04 stratis-1-private-377c6813ac5947c0b2d0d91e65e5642b-flex-thindata -> ../dm-2
lrwxrwxrwx. 1 root root       7 Jan 17 17:04 stratis-1-private-377c6813ac5947c0b2d0d91e65e5642b-flex-mdv -> ../dm-4
lrwxrwxrwx. 1 root root       7 Jan 17 17:04 stratis-1-private-377c6813ac5947c0b2d0d91e65e5642b-thinpool-pool -> ../dm-3
lrwxrwxrwx. 1 root root       7 Jan 17 17:04 stratis-1-377c6813ac5947c0b2d0d91e65e5642b-thin-fs-232c3a2f36da45a89532592570838ece -> ../dm-5
[root@ci~]# mount /dev/mapper/stratis-1-private-377c6813ac5947c0b2d0d91e65e5642b-flex-mdv /mnt
[root@ci~]# cat /mnt/filesystems/232c3a2f36da45a89532592570838ece.json
{"name":"fs1","uuid":"232c3a2f-36da-45a8-9532-592570838ece","thin_id":0,"size":2147483648,"created":1642456189}[root@ci~]# 
 
[root@ci~]# stratis report engine_state_report
{
    "errored_pools": [],
    "hopeless_devices": [],
    "pools": [
        {
            "blockdevs": {
                "cachedevs": [],
                "datadevs": [
                    {
                        "path": "/dev/loop0",
                        "uuid": "9550b846-ccc0-4276-b123-c46046a05a95"
                    }
                ]
            },
            "filesystems": [
                {
                    "name": "fs1",
                    "uuid": "232c3a2f-36da-45a8-9532-592570838ece"
                }
            ],
            "name": "p1",
            "uuid": "377c6813-ac59-47c0-b2d0-d91e65e5642b"
        }
    ]
}