作者：温蚊童鞋_612 | 来源：互联网 | 2023-09-17 14:08
HowtoCheckDeviceUUIDorFileSystemUUID.(DocID1505398.1)APPLIESTO:LinuxOS-VersionOracleLinux5
How to Check Device UUID or File System UUID. (Doc ID 1505398.1)
APPLIES TO:
Linux OS - Version Oracle Linux 5.0 and later
Oracle Cloud Infrastructure - Version N/A and later
Linux x86-64
Linux x86
GOAL
In Linux, sometimes the name of devices or file systems are not persistent which will bring system in trouble, in such situation specify UUID (universally unique identifier) is the solution to identify the only unique component in the system.
SOLUTION
1. Device uuid
In OL5.x:
# scsi_id -u -g -s /block/sda
35000c50032387713
In OL6.x:
# scsi_id --whitelisted /dev/sdd
3600144f0da627ad70000503ad6ce0006
Or:
# udevadm info --query=all --path=/sys/block/sda
P: /devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/target0:2:0/0:2:0:0/block/sda
N: sda
W: 99
S: block/8:0
S: disk/by-id/scsi-364403a78570b200018ac2cd20575ec04
S: disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0
S: disk/by-id/wwn-0x64403a78570b200018ac2cd20575ec04
E: UDEV_LOG=3
E: DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/target0:2:0/0:2:0:0/block/sda
E: MAJOR=8
E: MINOR=0
E: DEVNAME=/dev/sda
E: DEVTYPE=disk
E: SUBSYSTEM=block
E: MPATH_SBIN_PATH=/sbin
E: ID_SCSI=1
E: ID_VENDOR=LSI
E: ID_VENDOR_ENC=LSI
E: ID_MODEL=MRSASRoMB-4i
E: ID_MODEL_ENC=MRSASRoMB-4i
E: ID_REVISION=2.12
E: ID_TYPE=disk
E: ID_SERIAL_RAW=364403a78570b200018ac2cd20575ec04
E: ID_SERIAL=364403a78570b200018ac2cd20575ec04
E: ID_SERIAL_SHORT=64403a78570b200018ac2cd20575ec04
E: ID_WWN=0x64403a78570b2000
E: ID_WWN_VENDOR_EXTENSION=0x18ac2cd20575ec04
E: ID_WWN_WITH_EXTENSION=0x64403a78570b200018ac2cd20575ec04
E: ID_SCSI_SERIAL=0004ec7505d22cac1800200b57783a40
E: ID_BUS=scsi
E: ID_PATH=pci-0000:01:00.0-scsi-0:2:0:0
E: ID_PART_TABLE_TYPE=dos
E: LVM_SBIN_PATH=/sbin
E: DEVLINKS=/dev/block/8:0 /dev/disk/by-id/scsi-364403a78570b200018ac2cd20575ec04 /dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0 /dev/disk/by-id/wwn-0x64403a78570b200018ac2cd20575ec04
For multipath devices:
# multipath -ll -v
360080e500024a048000004044f3c64ee dm-0 SUN,LCSM100_F
size=95G features=‘1 queue_if_no_path‘ hwhandler=‘1 rdac‘ wp=rw
|-+- policy=‘round-robin 0‘ prio=6 status=active
| `- 7:0:0:0 sdb 8:16 active ready running
`-+- policy=‘round-robin 0‘ prio=1 status=enabled
`- 8:0:0:0 sdk 8:160 active ghost running
Note: the device uuid is fixed value, the uuid of dm-mp device should be identical with the uuid of its paths. In most of situation could not be modified unless the device supports dynamic uuid feature.
Usage:
The device uuid often being used to persistent the device name or dm-mpath name, following example bind the wwid with name oraasm1 persistently.
multipath {
wwid 36006048caf0b141598afa8e2875797a1
alias oraasm1
}
Note: the partition (such as sda1 sdb1) does not have uuid.
2. File system uuid
In OL5.x:
# blkid /dev/sda1
/dev/sda1: LABEL="/boot1" UUID="ae298adb-1b94-42a0-9dc9-a121c7561a5b" TYPE="ext3" SEC_TYPE="ext2"
# /lib/udev/vol_id /dev/sda1
ID_FS_USAGE=filesystem
ID_FS_TYPE=ext3
ID_FS_VERSION=1.0
ID_FS_UUID=ae298adb-1b94-42a0-9dc9-a121c7561a5b
ID_FS_LABEL=/boot1
ID_FS_LABEL_SAFE=boot1
Note: the /dev/sdxx must be formated as file system.
Usage:
Could specify uuid in /etc/fstab to bind the device with mount directory persistently.
UUID=xxx-xxx-xxx-xxx /mount_dir ext3 defaults 1 2
Note: file system uuid will be changed after re-create file system.
3. LVM2 uuid
# pvs -v
PV VG Fmt Attr PSize PFree DevSize PV UUID
/dev/sda2 vg0 lvm2 a-- 48.81G 0 48.83G xCJzmN-oJmL-kMFl-JCrb-lfoH-movY-6x6K6O
/dev/sda3 vg0 lvm2 a-- 48.81G 0 48.83G 9iXmmM-kKqV-OYDb-eSVN-ymCw-wwVk-uY6fXo
# lvs
LV VG #Seg Attr LSize Maj Min KMaj KMin Origin Snap% Move Copy% Log Convert LV UUID
lvroot vg0 3 -wi-ao 146.44G -1 -1 253 0 C0l0R2-KhH8-N7Nk-BhXn-MJhS-35dn-XXdL1B
lvasmlib vg1 1 -wi-a- 4.88G -1 -1 253 6 5nlcKy-1kvs-l7qb-eIts-tEs6-E2JG-RisWDx
# vgs -v
VG Attr Ext #PV #LV #SN VSize VFree VG UUID
vg0 wz--n- 32.00M 3 1 0 146.44G 0 ereADB-2w9v-O2P9-58OS-RN9Q-t2pV-8wXpSc
vg1 wz--n- 4.00M 3 3 0 139.71G 9.95G LczKdV-Nq82-lNrr-EmI1-cerd-numb-1qV6m4
Usage:
In some case need recover some pv device, use the --uuid and --restorefile arguments of the pvcreate command to restore the physical volume. The following command restores the physical volume label with the backuped metadata.
# pvcreate --uuid "0YnHNn-1COx-dohx-bwPf-aLyl-pO8F-f5PI5R" --restorefile /etc/lvm/archive/vg0_00000-1324010847.vg /dev/sda2
Physical volume "/dev/sda2" successfully created
Note: lvm2 uuid will be changed after re-create.
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