Description

This article addresses generic queries about file system check logs in MX router during boot sequence.

Symptoms

Below mentioned logs will be observed while booting up the device where Unref files are seen.

 

***** FILE SYSTEM MARKED CLEAN *****

** /dev/gpt/var

** Last Mounted on /.mount/var

** Phase 1 - Check Blocks and Sizes

** Phase 2 - Check Pathnames

** Phase 3 - Check Connectivity

** Phase 4 - Check Reference Counts

UNREF FILE I=802714 OWNER=root MODE=140755

SIZE=0 MTIME=Aug 19 07:35 2022

CLEAR? yes

 

UNREF FILE I=802800 OWNER=root MODE=140755

SIZE=0 MTIME=Sep 1 09:54 2024

RECONNECT? yes

NO lost+found DIRECTORY

CREATE? yes

 

UNREF FILE I=882841 OWNER=root MODE=100640

SIZE=2621440 MTIME=Mar 19 17:21 2024

CLEAR? yes

** Phase 5 - Check Cyl groups

 

FREE BLK COUNT(S) WRONG IN SUPERBLK

SALVAGE? yes

 

SUMMARY INFORMATION BAD

SALVAGE? yes

 

BLK(S) MISSING IN BIT MAPS

SALVAGE? yes

937 files, 653853 used, 7226430 free (454 frags, 903247 blocks, 0.0% fragmentation)

***** FILE SYSTEM STILL DIRTY *****

***** FILE SYSTEM WAS MODIFIED *****

RESTART? yes

 

** /dev/gpt/var

** Last Mounted on /.mount/var

** Phase 1 - Check Blocks and Sizes

** Phase 2 - Check Pathnames

** Phase 3 - Check Connectivity

** Phase 4 - Check Reference Counts

** Phase 5 - Check Cyl groups

937 files, 653853 used, 7226430 free (454 frags, 903247 blocks, 0.0% fragmentation)

***** FILE SYSTEM MARKED CLEAN *****

Solution

While booting up the device, system will perform file system checks, and it will not cause any file system corruption during the boot sequence irrespective of soft or hard reboot.

During the boot up sequence, Junos operating system will perform a file system check to ensure that there’s no bad blocks observed or any corrupted files and if there’s any, the system will eventually repair it accordingly which is what we observed in the logs below.

 

UNREF FILE I=882841 OWNER=root MODE=100640

SIZE=2621440 MTIME=Mar 19 17:21 2024

CLEAR? yes

** Phase 5 - Check Cyl groups

FREE BLK COUNT(S) WRONG IN SUPERBLK

SALVAGE? yes

 

SUMMARY INFORMATION BAD

SALVAGE? yes

BLK(S) MISSING IN BIT MAPS

SALVAGE? yes

937 files, 653853 used, 7226430 free (454 frags, 903247 blocks, 0.0% fragmentation)

***** FILE SYSTEM STILL DIRTY *****

***** FILE SYSTEM WAS MODIFIED *****

RESTART? yes

 

** /dev/gpt/var

** Last Mounted on /.mount/var

** Phase 1 - Check Blocks and Sizes

** Phase 2 - Check Pathnames

** Phase 3 - Check Connectivity

** Phase 4 - Check Reference Counts

** Phase 5 - Check Cyl groups

937 files, 653853 used, 7226430 free (454 frags, 903247 blocks, 0.0% fragmentation)

***** FILE SYSTEM MARKED CLEAN *****

 

We could notice that the file system is clean after the checks performed during the boot sequence; however, if there are more unref files with the above mentioned checks being negative, it requires USB installation to clear the file system corruption.

To check the health status of the router after the unscheduled reboot, we can collect the below outputs.

 

> show krt queue

> show krt state

> show route summary

> show chassis power no-forwarding

> show system boot-messages no-forwarding

> show system storage no-forwarding

> show system virtual-memory no-forwarding

> show system buffer no-forwarding

Modification History

2024-09-17 : Article Created