we installed RHEL 7.9 version on physical machine., when sda device was the OS
machine have the following disks.
sda - OS disk
sdb - data disk
sdc - data disk
after reboot OS disk device changed to sdc as the following and sda became as part of data disk
sdc 8:32 0 558.4G 0 disk
├─sdc1 8:33 0 500M 0 part /boot
└─sdc2 8:34 0 557.9G 0 part
├─VG-VOL_root 253:0 0 100G 0 lvm /
├─VG-VOL_swap 253:1 0 16G 0 lvm
├─VG-VOL_var 253:2 0 200G 0 lvm /var
we assume on some next reboots sdc maybe ? will change again to sda as should be
but how to prevent sda disk to change to another device? after reboot ?
according to red-hat doc they recommended to set the following:
users can modify kernel boot parameters by appending "scsi_mod.scan=sync" in the /etc/sysconfig/grub file to get more consistent disk lette It will not guarantee consistent device names in all cases. This option should be used with caution as it slows down disk discovery procedure and thus whole boot process.
but is this configuration to set scsi_mod.scan=sync in /etc/sysconfig/grub is really helps?
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=VG/VOL_root rd.lvm.lv=VG/lv_swap rhgb quiet"
GRUB_DISABLE_RECOVERY="true"
scsi_mod.scan=sync <---------------
what are the other options that we can to do in order to avoid sda disk device to change after reboot?
other some useful details from the server
ls -ltr /dev/disk/by-id | grep sdc
lrwxrwxrwx 1 root root 9 Dec 28 11:43 wwn-0x6588a5a0ef7f4d0023880046051e7a74 -> ../../sdc
lrwxrwxrwx 1 root root 9 Dec 28 11:43 scsi-36588a5a0ef7f4d0023880046051e7a74 -> ../../sdc
lrwxrwxrwx 1 root root 10 Dec 28 11:43 wwn-0x6588a5a0ef7f4d0023880046051e7a74-part2 -> ../../sdc2
lrwxrwxrwx 1 root root 10 Dec 28 11:43 scsi-36588a5a0ef7f4d0023880046051e7a74-part2 -> ../../sdc2
lrwxrwxrwx 1 root root 10 Dec 28 11:43 lvm-pv-uuid-2Ee6HA-9vVx-bUVq-noyG-U0Nq-AVMz-oI56ji -> ../../sdc2
lrwxrwxrwx 1 root root 10 Dec 28 11:43 wwn-0x6588a5a0ef7f4d0023880046051e7a74-part1 -> ../../sdc1
lrwxrwxrwx 1 root root 10 Dec 28 11:43 scsi-36588a5a0ef7f4d0023880046051e7a74-part1 -> ../../sdc1
cat /etc/fstab | grep boot
UUID=f57f0346-9e6c-429e-b80f-3871334bae35 /boot xfs defaults 0 0
1 Answers