Impac on filer in case of DNS server goes down - Storage

This is a discussion on Impac on filer in case of DNS server goes down - Storage ; Anyone can describe the impact on Netapp filer if primary DNS server goes down. Configuration is as follows :- In "/etc/resolv.conf" file more than one DNS servers are mentioned. Primarily filer is bound with NIS as nis is first entry ...

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Thread: Impac on filer in case of DNS server goes down

  1. Impac on filer in case of DNS server goes down

    Anyone can describe the impact on Netapp filer if primary DNS server
    goes down.
    Configuration is as follows :-
    In "/etc/resolv.conf" file more than one DNS servers are mentioned.
    Primarily filer is bound with NIS as nis is first entry in "/etc/
    nsswitch.conf" file and dns is second.
    In "/etc/hosts" file hostname are not fully qualified.
    Filer is also bound with WINS as serving CIFS service also.


  2. Re: Impac on filer in case of DNS server goes down

    On 8 Feb 2007 21:52:17 -0800, "Raju Mahala"
    wrote:

    >Anyone can describe the impact on Netapp filer if primary DNS server
    >goes down.
    >Configuration is as follows :-
    >In "/etc/resolv.conf" file more than one DNS servers are mentioned.
    >Primarily filer is bound with NIS as nis is first entry in "/etc/
    >nsswitch.conf" file and dns is second.
    >In "/etc/hosts" file hostname are not fully qualified.
    >Filer is also bound with WINS as serving CIFS service also.


    If you have more than one DNS server in the resolve.conf then you have
    no issue, so long as at least one of them is up and servicing
    requests.
    The time it takes to run down the list is minimal and not something
    users would ever see. Batch jobs may pause for a few hundred
    milliseconds while the filer figures out which server is responding
    but that's about it.

    The nice thing about hosts files is that the filer will check that
    first. So regardless of FQDN it will do a lookup, if there hold in
    cache, and never actually go to the DNS server.
    Scalability is obviously an issue there though, which is why DNS was
    invented in the first place.

    But I digress.

    You are using NIS as your primary name service? I would counsel
    against that. your NIS servers are already serving passwd, groups,
    netgroups, etc., what then are your DNS servers to do?

    ~F

  3. Re: Impac on filer in case of DNS server goes down

    On Feb 10, 12:52 am, Faeandar wrote:
    > On 8 Feb 2007 21:52:17 -0800, "Raju Mahala"
    > wrote:
    >
    > >Anyone can describe the impact on Netapp filer if primary DNS server
    > >goes down.
    > >Configuration is as follows :-
    > >In "/etc/resolv.conf" file more than one DNS servers are mentioned.
    > >Primarily filer is bound with NIS as nis is first entry in "/etc/
    > >nsswitch.conf" file and dns is second.
    > >In "/etc/hosts" file hostname are not fully qualified.
    > >Filer is also bound with WINS as serving CIFS service also.

    >
    > If you have more than one DNS server in the resolve.conf then you have
    > no issue, so long as at least one of them is up and servicing
    > requests.
    > The time it takes to run down the list is minimal and not something
    > users would ever see. Batch jobs may pause for a few hundred
    > milliseconds while the filer figures out which server is responding
    > but that's about it.
    >
    > The nice thing about hosts files is that the filer will check that
    > first. So regardless of FQDN it will do a lookup, if there hold in
    > cache, and never actually go to the DNS server.
    > Scalability is obviously an issue there though, which is why DNS was
    > invented in the first place.
    >
    > But I digress.
    >
    > You are using NIS as your primary name service? I would counsel
    > against that. your NIS servers are already serving passwd, groups,
    > netgroups, etc., what then are your DNS servers to do?
    >
    > ~F


    As I know DNS is used only to resolve host names, not for
    authentication. Please correct if I am wrong.
    Is there any way to provide passwd, groups, netgroups services through
    DNS ?

    In our environment NIS is used for UNIX authentication and name
    resolution at UNIX clients. WINS is used for windows authentication at
    windows client.
    Host name resolution at windows client is primarily done through DNS
    but at UNIX client primarily through NIS and if not found then DNS.

    I have one query why filer needs client host name resolution service ?
    host name resolution should be done at client end if client needs
    service from filer. So if we doesn't configure DNS at filer then what
    we will loose ?

    Raju


  4. Re: Impac on filer in case of DNS server goes down

    On 10 Feb 2007 01:54:29 -0800, "Raju Mahala"
    wrote:

    >On Feb 10, 12:52 am, Faeandar wrote:
    >> On 8 Feb 2007 21:52:17 -0800, "Raju Mahala"
    >> wrote:
    >>
    >> >Anyone can describe the impact on Netapp filer if primary DNS server
    >> >goes down.
    >> >Configuration is as follows :-
    >> >In "/etc/resolv.conf" file more than one DNS servers are mentioned.
    >> >Primarily filer is bound with NIS as nis is first entry in "/etc/
    >> >nsswitch.conf" file and dns is second.
    >> >In "/etc/hosts" file hostname are not fully qualified.
    >> >Filer is also bound with WINS as serving CIFS service also.

    >>
    >> If you have more than one DNS server in the resolve.conf then you have
    >> no issue, so long as at least one of them is up and servicing
    >> requests.
    >> The time it takes to run down the list is minimal and not something
    >> users would ever see. Batch jobs may pause for a few hundred
    >> milliseconds while the filer figures out which server is responding
    >> but that's about it.
    >>
    >> The nice thing about hosts files is that the filer will check that
    >> first. So regardless of FQDN it will do a lookup, if there hold in
    >> cache, and never actually go to the DNS server.
    >> Scalability is obviously an issue there though, which is why DNS was
    >> invented in the first place.
    >>
    >> But I digress.
    >>
    >> You are using NIS as your primary name service? I would counsel
    >> against that. your NIS servers are already serving passwd, groups,
    >> netgroups, etc., what then are your DNS servers to do?
    >>
    >> ~F

    >
    >As I know DNS is used only to resolve host names, not for
    >authentication. Please correct if I am wrong.
    >Is there any way to provide passwd, groups, netgroups services through
    >DNS ?


    Not that I'm aware of.

    >
    >In our environment NIS is used for UNIX authentication and name
    >resolution at UNIX clients. WINS is used for windows authentication at
    >windows client.
    >Host name resolution at windows client is primarily done through DNS
    >but at UNIX client primarily through NIS and if not found then DNS.
    >
    >I have one query why filer needs client host name resolution service ?
    >host name resolution should be done at client end if client needs
    >service from filer. So if we doesn't configure DNS at filer then what
    >we will loose ?


    The filer needs host name resolution if you have any export access
    controls based on host or netgroup. That's all I can think of at the
    moment, and even that can be put in NIS or in local host file.

    So technically you would lose nothing if you do not configure DNS.

    ~F

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