I want to share the following very strange behavior , that for me it's not make sense but its a a fact on our production RHEL 7.2 server
disks are VMDK
from df -h we can see the following:
sdb /DB_STORAGE_1
and its also defined in /etc/fstab file
/dev/sdb /DB_STORAGE_1 ext4 defaults,noatime 0 0
but when I run lsblk -f , we can see that FSTYPE not exist on sdb disk , ( and also not the UUID ) ,
but FSTYPE exist on others disks as sdc / sdd
lsblk -f
sdb /DB_STORAGE_1
sdc ext4 d77598ec-9f19-48dc-b364-bb60b0396019 /DB_STORAGE_2
sdd ext4 bf48c193-d58c-4ef3-b717-ea681ec1684a /DB_STORAGE_3
for sure I can tell everyone that filesystem ext4 was created in the past for all disks sdb / sdc /sdd
so we do not understand how it can be that ext4 filesystem not displayed by lsblk -f
second - under /DB_STORAGE_1 , we can see the relevant data and folers/files
as all know in principle, we can't mount disk to folder without filesystem that created by mkfs command
so how it can be? , what could be the reason/s that ext4 not exist from lsblk -f ?
we also see that from mount command.
/dev/sdb on /DB_STORAGE_1 type ext4 (rw,noatime,data=ordered)
when I run blkid I get
/dev/sdb: UUID="74d50923-817d-423c-9736-743863ebe5d2" TYPE="ext4"
so how it can be??
from dmesg I get that
dmesg -T | grep sdb
[Tue Mar 7 13:27:31 2023] sd 0:0:2:0: [sdb] 41943040 512-byte logical blocks: (21.4 GB/20.0 GiB)
[Tue Mar 7 13:27:31 2023] sd 0:0:2:0: [sdb] Write Protect is off
[Tue Mar 7 13:27:31 2023] sd 0:0:2:0: [sdb] Mode Sense: 3b 00 00 00
[Tue Mar 7 13:27:31 2023] sd 0:0:2:0: [sdb] Write cache: disabled, read cache: disabled, doesn't support DPO or FUA
[Tue Mar 7 13:27:31 2023] sdb: unknown partition table
[Tue Mar 7 13:27:31 2023] sd 0:0:2:0: [sdb] Attached SCSI disk
[Tue Mar 7 14:47:27 2023] EXT4-fs (sdb): mounted filesystem with ordered data mode. Opts: (null)
uptime
22:25:08 up 7 days, 8:57, 2 users, load average: 3.75, 3.41, 3.52
smartctl -a /dev/sdb
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.10.0-327.el7.x86_64] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Vendor: VMware
Product: Virtual disk
Revision: 2.0
User Capacity: 21,474,836,480 bytes [21.4 GB]
Logical block size: 512 bytes
LU is thin provisioned, LBPRZ=1
Rotation Rate: 15000 rpm
Device type: disk
Local Time is: Tue Mar 14 22:30:09 2023 UTC
SMART support is: Unavailable - device lacks SMART capability.
=== START OF READ SMART DATA SECTION ===
Error Counter logging not supported
