3750-24TS-S error

Discussion in 'Cisco' started by braydonsdad, Jan 2, 2008.

  1. braydonsdad

    braydonsdad Guest

    I am getting the following error when entering a mtu configuration on
    this switch:

    vb:: Read-only file system

    I have posted the sh ver and the configuration below. Please let me
    know if you have ever seen this before and what the work around is.

    Switch#config t
    Enter configuration commands, one per line. End with CNTL/Z.
    Switch(config)#system mtu 1546
    vb:: Read-only file system
    Changes to the system MTU will not take effect until the next reload
    is done
    Switch(config)#system mtu jumbo 9000
    vb:: Read-only file system
    Changes to the system jumbo MTU will not take effect until the next
    reload is done

    sh ver
    Cisco IOS Software, C3750 Software (C3750-IPBASE-M), Version
    12.2(35)SE5, RELEASE SOFTWARE (fc1)
    Copyright (c) 1986-2007 by Cisco Systems, Inc.
    Compiled Thu 19-Jul-07 19:15 by nachen
    Image text-base: 0x00003000, data-base: 0x01080000

    ROM: Bootstrap program is C3750 boot loader
    BOOTLDR: C3750 Boot Loader (C3750-HBOOT-M) Version 12.2(25r)SEC,

    Switch uptime is 1 minute
    System returned to ROM by power-on
    System image file is "flash:c3750-ipbase-mz.122-35.SE5/c3750-ipbase-mz.

    cisco WS-C3750-24TS (PowerPC405) processor (revision M0) with 118784K/
    12280K bytes of memory.
    Processor board ID CAT1122NKPD
    Last reset from power-on
    1 Virtual Ethernet interface
    24 FastEthernet interfaces
    2 Gigabit Ethernet interfaces
    The password-recovery mechanism is enabled.
    512K bytes of flash-simulated non-volatile configuration memory.
    Base ethernet MAC Address : 00:1D:45:83:5D:00
    Motherboard assembly number : 73-9677-10
    Power supply part number : 341-0034-01
    Motherboard serial number : FDO11320J0D
    Power supply serial number : PHI1109B17Q
    Model revision number : M0
    Motherboard revision number : B0
    Model number : WS-C3750-24TS-S
    System serial number : CAT1122NKPD
    Top Assembly Part Number : 800-25857-02
    Top Assembly Revision Number : F0
    Version ID : V02
    CLEI Code Number : CNMV100CRE
    Hardware Board Revision Number : 0x01

    Switch Ports Model SW Version SW
    ------ ----- ----- ----------
    * 1 26 WS-C3750-24TS 12.2(35)SE5 C3750-

    --More--  Configuration register is 0xF
    braydonsdad, Jan 2, 2008
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  2. braydonsdad

    braydonsdad Guest

    When I save the config and restart I type this command and the mtu
    settings were not changed.

    Switch#sh system mtu

    System MTU size is 1500 bytes
    System Jumbo MTU size is 1500 bytes
    Routing MTU size is 1500 bytes
    braydonsdad, Jan 2, 2008
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  3. braydonsdad

    braydonsdad Guest

    Does anyone know how to change the permissions on a file system in the
    Cisco OS?
    braydonsdad, Jan 2, 2008
  4. braydonsdad

    Trendkill Guest

    What is your config register set to in show startup?
    Trendkill, Jan 2, 2008
  5. braydonsdad

    braydonsdad Guest

    it is set to 0xF
    braydonsdad, Jan 2, 2008
  6. braydonsdad

    Trendkill Guest

    Not sure if that is your problem or not, but mine are set to 0x2102.
    I know config registers can restrict configuration changes, so if this
    isn't a production switch, I'd consider changing it. Or google it and
    see what you find. Either way, I manage hundred of routers/switches,
    and all non-labs are set to 0x2102 per the standard.
    Trendkill, Jan 2, 2008
  7. braydonsdad

    Trendkill Guest

    I saw a post somewhere else that says 0xf is fine for your hardware
    (all my stuff is routers or 6500s for the most part) so perhaps my
    suspicion is wrong. Not sure what else would block that. I have had
    to set mtu to 9k in the past for an Oracle cluster on an IOS based
    switch, and reboot make it work fine, but it was a 3560 if I recall
    correctly. Hopefully someone else can point you in the right
    direction if I'm on the wrong track.
    Trendkill, Jan 2, 2008
  8. braydonsdad

    Trendkill Guest

    do a show file systems, and paste the output. I'm going off of this
    link, still trying to figure out how to change the permissions
    presuming you are showing nvram as RO and not RW. Let me know.
    Trendkill, Jan 3, 2008
  9. braydonsdad

    Trendkill Guest

    Oops, here is the link:

    Trendkill, Jan 3, 2008
  10. braydonsdad

    braydonsdad Guest

    vb: is set to ro. I wonder if this is just a bad batch of switches
    from Cisco. Every switch I have seen the vb: is set to rw.

    Switch#sh file systems
    File Systems:

    Size(b) Free(b) Type Flags Prefixes
    * 15998976 6371328 flash rw flash: flash1:
    - - opaque ro vb:
    - - opaque ro bs:
    - - opaque rw system:
    524288 524236 nvram rw nvram:
    - - opaque ro xmodem:
    - - opaque ro ymodem:
    - - opaque rw null:
    - - opaque ro tar:
    - - network rw tftp:
    - - network rw rcp:
    - - network rw http:
    - - network rw ftp:
    - - opaque ro cns:

    braydonsdad, Jan 3, 2008
  11. braydonsdad

    make Guest

    Switch#config t

    And you saved your configuration before reload? (copy running-config
    make, Jan 3, 2008
  12. braydonsdad

    braydonsdad Guest

    braydonsdad, Jan 3, 2008
  13. braydonsdad

    notaccie Guest

    3750-24TS are 10/100.

    from the command ref. guide for your ver.

    Gigabit Ethernet ports operating at 1000 Mbps are not affected by the
    system mtu command, and 10/100-Mbps ports are not affected by the
    system mtu jumbo command.

    can't do 9k frames on 3750 10/100, I think.
    notaccie, Jan 5, 2008
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