Ajju711
Contributor
Contributor

what is bootUUID and how is it determined

So I have a host machine with two physical disks and I'd like to install two different versions (6.7 and 7.0) on these two disks. So I know that I need to press SHIFT+O to modify the kernel command line to select the UUID of the partition to boot from

But I am unable to figure out what goes into 'bootUUID=' field of the kernel command line. I was expecting the bootUUID to be a GUID of the boot partition on the disk currently being used but it seems thats its coming from someplace else

My scsidevs:
/vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0 # esxcfg-scsidevs -u
Primary UID Other UID
mpx.vmhba0:C0:T0:L0 vml.0005000000766d686261303a303a30
naa.600508b1001c01a5eaf8ac72d8574ac8 vml.0200010000600508b1001c01a5eaf8ac72d8574ac84c4f47494341
naa.600508b1001c1124b26a25b4ca9bafa9 vml.0200020000600508b1001c1124b26a25b4ca9bafa94c4f47494341

so the first one is a CDROM. To identify the currently active partition from where we've booted, I do:

/vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0 # esxcfg-info -s | grep -A10 "Diagnostic Partition"
\==+Diagnostic Partition :
|----Is Active................................................true
\==+Disk Lun Partition :
|----Name..................................................naa.600508b1001c01a5eaf8ac72d8574ac8:9
|----Partition Number......................................9
|----Start Sector..........................................1843200
|----End Sector............................................7086079
|----Partition Type........................................252
|----Console Device......................................../vmfs/devices/disks/naa.600508b1001c01a5eaf8ac72d8574ac8:9
|----DevFS Path............................................/vmfs/devices/disks/naa.600508b1001c01a5eaf8ac72d8574ac8:9
|----Size..................................................2684354560

This tells me that 'naa.600508b1001c01a5eaf8ac72d8574ac8' is the disk that houses the diagnostic partition so it should also be the one holding the main boot partition as well.

so let me check the partition table for this disk

/vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0/ # partedUtil getptbl "/vmfs/devices/disks/naa.600508b1001c01a5eaf8ac72d8574ac8"
gpt
17844 255 63 286677120
1 64 8191 C12A7328F81F11D2BA4B00A0C93EC93B systemPartition 128
5 8224 520191 EBD0A0A2B9E5443387C068B6B72699C7 linuxNative 0
6 520224 1032191 EBD0A0A2B9E5443387C068B6B72699C7 linuxNative 0
7 1032224 1257471 9D27538040AD11DBBF97000C2911D1B8 vmkDiagnostic 0
8 1257504 1843199 EBD0A0A2B9E5443387C068B6B72699C7 linuxNative 0
9 1843200 7086079 9D27538040AD11DBBF97000C2911D1B8 vmkDiagnostic 0
2 7086080 15472639 EBD0A0A2B9E5443387C068B6B72699C7 linuxNative 0
3 15472640 286677079 AA31E02A400F11DB9590000C2911D1B8 vmfs 0

Let's print more information about bootbank and alt-bootbank:
/vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0 # ls -lrt /
total 797
lrwxrwxrwx 1 root root 18 Mar 26 2019 vmupgrade -> /locker/vmupgrade/
lrwxrwxrwx 1 root root 4 Mar 26 2019 sbin -> /bin
-r--r--r-- 1 root root 225445 Mar 26 2019 bootpart4kn.gz
-r--r--r-- 1 root root 340570 Mar 26 2019 bootpart.gz
-r-x------ 1 root root 19681 Feb 9 10:02 local.tgz
drwxr-xr-x 1 root root 512 Feb 9 12:08 tardisks.noauto
drwxr-xr-x 1 root root 512 Feb 9 12:08 vmimages
drwxr-xr-x 1 root root 512 Feb 9 12:08 vmfs
drwxr-xr-x 1 root root 512 Feb 9 12:08 usr
drwxr-xr-x 1 root root 512 Feb 9 12:08 tardisks
drwxr-xr-x 1 root root 512 Feb 9 12:08 lib
drwxr-xr-x 1 root root 512 Feb 9 12:09 opt
drwxr-xr-x 1 root root 512 Feb 9 12:09 mbr
drwxr-xr-x 1 root root 512 Feb 9 12:09 lib64
drwxr-xr-x 1 root root 512 Feb 9 12:09 bin
lrwxrwxrwx 1 root root 49 Feb 9 12:09 store -> /vmfs/volumes/5f8afaf2-f3c3f529-c780-000e1e53a4b0
lrwxrwxrwx 1 root root 49 Feb 9 12:09 bootbank -> /vmfs/volumes/86f8ce75-a9ab0da8-7e2f-3058d3996dbc
lrwxrwxrwx 1 root root 49 Feb 9 12:09 altbootbank -> /vmfs/volumes/32eca87e-eb81f3f0-0df3-24647ab64f25
lrwxrwxrwx 1 root root 49 Feb 9 12:09 scratch -> /vmfs/volumes/5f8afb0f-ccbffb00-dcc4-000e1e53a4b0
lrwxrwxrwx 1 root root 29 Feb 9 12:09 productLocker -> /locker/packages/vmtoolsRepo/
lrwxrwxrwx 1 root root 6 Feb 9 12:09 locker -> /store
drwxr-xr-x 1 root root 512 Feb 9 12:09 var
lrwxrwxrwx 1 root root 54 Feb 9 12:10 qfle3 -> /vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0/qfle
drwxr-xr-x 1 root root 512 Feb 9 12:10 etc
drwxrwxrwt 1 root root 512 Feb 9 17:01 tmp
drwxr-xr-x 1 root root 131072 Feb 9 17:15 proc
drwxr-xr-x 16 root root 512 Feb 9 17:15 dev

/vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0 # vmkfstools -Ph /vmfs/volumes/86f8ce75-a9ab0da8-7e2f-3058d3996dbc
vfat-0.04 (Raw Major Version: 0) file system spanning 1 partitions.
File system label (if any):
Mode: private
Capacity 249.7 MB, 104.5 MB available, file block size 4 KB, max supported file size 0 bytes
Disk Block Size: 512/0/0
UUID: 86f8ce75-a9ab0da8-7e2f-3058d3996dbc
Partitions spanned (on "disks"):
naa.600508b1001c01a5eaf8ac72d8574ac8:6
Is Native Snapshot Capable: NO

/vmfs/volumes/5b9ac67c-8e9f1e57-c8ce-000e1e53a4b0 # vmkfstools -Ph /vmfs/volumes/86f8ce75-a9ab0da8-7e2f-3058d3996dbc
vfat-0.04 (Raw Major Version: 0) file system spanning 1 partitions.
File system label (if any):
Mode: private
Capacity 249.7 MB, 104.5 MB available, file block size 4 KB, max supported file size 0 bytes
Disk Block Size: 512/0/0
UUID: 86f8ce75-a9ab0da8-7e2f-3058d3996dbc
Partitions spanned (on "disks"):
naa.600508b1001c01a5eaf8ac72d8574ac8:6
Is Native Snapshot Capable: NO

However on the boot screen I see that the kernel parameter 'bootUUID' doesn't match either of these UUIDs from above. Instead it is this
kernel command linekernel command line

I am unable to determine where is this coming from. Can someone shed a light about this? What is this 'bootUUID' and how is it derived?

Tags (4)
0 Kudos
0 Replies