Understand What Happens When Memory Failures Occur; Check The Router File System And Boot Disk - Juniper JUNOS - NETWORK OPERATION GUIDE REV1 Network Operation Manual

JUNOS Internet Software Network Operations Guide: Hardware
Step 3: Understand What Happens When Memory Failures Occur
Step 4: Check the Router File System and Boot Disk
Action
Action
Sample Output
!
154
Verifying Routing Engine Failure
Most Juniper Networks Routing Engines support Error Checking and Correction
(ECC) protected memory. There are two types of memory errors: single-bit and
multiple-bit.
A single-bit error is when a single 0 or 1 bit is incorrect. The system detects and
corrects single-bit errors, then logs the event in the /var/log/eccd file. If there are
persistent single-bit errors, the Routing Engine controller reboots the Routing
Engine. Persistent single-bit errors could be a symptom of bad RAM.
Multiple-bit errors are when multiple bits are incorrect. By default, if a multiple-bit
error is detected, a nonmaskable interrupt (NMI) is generated to interrupt the
Routing Engine and panic the kernel causing the router to subsequently reboot. The
Routing Engine panics the kernel, and leaves a vmcore file.Multi-bit parity error
detection was implemented in JUNOS software release 5.3 and above.
Table 43 specifies the storage media by Routing Engine type. The device names are
displayed when the router boots. To display the Routing Engine type on some
routers, use the show chassis hardware CLI command.
Table 43: Storage Media Device Names
RE-M40
Storage Media (RE1)
Flash drive ad0
Hard disk ad2
Removable media afd0
To check the router file system and on which disk the router booted, use the
following CLI command:
user@host> show system storage
user@host> show system storage
Filesystem 1K-blocks
/dev/ad0s1a 65687
devfs 16
/dev/vn1 9310
/dev/vn2 8442
/packages/mnt/jkernel-5.0R5.1
/dev/vn3 11486
/dev/vn4 5742
/dev/vn5 1488
/packages/mnt/jcrypto-5.0R5.1
/dev/vn6 792
mfs:181 762223
/dev/ad0s1e 25263
procfs 4
/dev/ad1s1f 7156052
RE-400 RE-333 (RE2)/
(RE5) RE-600 (RE3)
ad0 ad0
ad1 ad1
ad3 ad3
Used Avail Capacity
26701 33732 44%
16 0 100%
9310 0 100%
8442 0 100%
11486 0 100%
5742 0 100%
1488 0 100%
792 0 100%
3 701243 0%
7 23235 0%
4 0 100%
337194 6246374 5%
RE-1600
(RE4)
ad0
ad1
ad3 and ad4
Mounted on
/
/dev/
/packages/mnt/jbase
/packages/mnt/jpfe-5.0R5.1
/packages/mnt/jroute-5.0R5.1
/packages/mnt/jdocs-5.0R5.1
/tmp
/config
/proc
/var