Couldn't find a low level format procedure for MX80 nand. Yet replacing nand1 with a USB flash drive is feasible with these steps:
1. Create a snapshot on a USB drive. Example uses a SanDisk 8GB drive. Most 4 to 32GB drives should work with an MX80 running
JUNOS 20.4R3.8.
root@edge1> request system snapshot media usb partition
Clearing current label...
Partitioning usb media (da2) ...
Doing the initial labeling...
Partitions on snapshot:
Partition Mountpoint Size Snapshot argument
a / 637MB root-size
e /config 101MB config-size
f /var 6GB var-size
Running newfs (637MB) on usb media / partition (da2s1a)...
Running newfs (101MB) on usb media /config partition (da2s1e)...
Running newfs (6GB) on usb media /var partition (da2s1f)...
Copying '/dev/da0s1a' to '/dev/da2s1a' .. (this may take a few minutes)
Copying '/dev/da0s1e' to '/dev/da2s1e' .. (this may take a few minutes)
The following filesystems were archived: / /config
root@edge1>
2. Change/etc/fstab entries from nand1 (da1) to USB (da2). Commented out da1s1b partitions (/tmp, /mfs) since the snapshot didn't create a da2s1b partition. Without dedicated partitions, those directories will become part of the root filesystem (/dev/da0s1a).
# Device Mountpoint FStype Options Dump Pass#
/dev/da0s1a / ufs rw 1 1
/dev/da0s1e /config ufs rw 2 2
proc /proc procfs rw 0 0
/dev/da2s1f /var ufs rw,noauto 2 2
/dev/da0s1b none swap sw 0 0
#/dev/da1s1b /tmp mfs rw,noauto 0 0
#/dev/da1s1b /mfs mfs rw,noauto 0 0
/dev/da2s1a /altroot ufs rw,noauto 2 0
/dev/da2s1e /altconfig ufs rw,noauto 2 0
3. Change boot order to only nand-flash0. Intent was to use nand-flash0,usb (USB last) but it kept changing to usb,nand-flash0 (USB first).
root@edge1% sysctl -a | grep bootdev
machdep.currbootdev: nand-flash0
machdep.nextbootdev: usb
machdep.bootdevs: usb,nand-flash0,nand-flash1
root@core1% sysctl -w machdep.bootdevs=nand-flash0
machdep.bootdevs: usb,nand-flash0,nand-flash1 -> nand-flash0
root@core1% sysctl -a | grep bootdev
machdep.currbootdev: nand-flash0
machdep.nextbootdev: usb
machdep.bootdevs: nand-flash0
4. Reboot.
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JAlvarez
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Original Message:
Sent: 05-23-2022 19:23
From: Jesus Alvarez
Subject: MX80 - Format nand1
One of our MX80 routers appears to have a bad sector in nand1 (da1). Over the past 3 months it has locked up twice after displaying this message on the console.
g_vfs_done():da1s1a[WRITE(offset=8192, length=2048)]error = 5
The nand1 device (da1) is recognized at boot and the da1s1a partition completes fsck normally.
root@edge1% dmesg|grep da1da1 at umass-sim1 bus 1 target 0 lun 0da1: <ATP ATP IG eUSB 1100> Fixed Direct Access SCSI-4 deviceda1: 40.000MB/s transfersda1: 3838MB (7860224 512 byte sectors: 255H 63S/T 489C)root@edge1% fsck /dev/da1s1a** /dev/da1s1a** Last Mounted on /mnt** Phase 1 - Check Blocks and Sizes** Phase 2 - Check Pathnames** Phase 3 - Check Connectivity** Phase 4 - Check Reference Counts** Phase 5 - Check Cyl groups1051 files, 15444 used, 437748 free (44 frags, 54713 blocks, 0.0% fragmentation)
Router is running JUNOS 20.4R3.8. Is there a utility on the JUNOS MX distribution to low level format a nand device (similar to nand-mediack on other JUNOS platforms)? A low level format should remap any bad sectors.
Else, can a USB flash drive be used for /altroot, /altconfig and /var (e.g. to substitute nand1)? This MX80 is scheduled to be replaced around the end of the year, but should be operational until then.
Thanks.
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JAlvarez
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