Re: Bad NFS performance with Linux.. please help

From: Aaron Sherman (ajs@ajs.com)
Date: Sat Aug 12 2000 - 10:49:04 EDT

  • Next message: Aaron Sherman: "Re: Filer storage for databases, seriously? (Was: Re: NetApp questions)"

    On Sat, Aug 12, 2000 at 01:54:53AM -0700, Eyal Traitel wrote:
    > I can suggest you to check:
    >
    > 1. Network cards and switches/routers between the Linuxes and the
    > filers - check for 100mbit full duplex settings - check in the
    > filer and the linux for nfsstat and netstat errors.

    Good plan. It sounds to me like either an NFS tuning issue or the
    dual-processor, dual-ethernet locking problems that caused the
    Mindcraft benchmarks to be so horrible. You might actually get better
    performance under 2.2 if you dump the extra processor and buy a couple
    more servers (relatively cheap if you're going with, say, VA/Linux).

    > 2. I don't have experience with NFS on linux, but I know that there
    > were a lot of nfs changes in the last kernels, so even if it
    > worked OK before, maybe you should just consider to upgrade the
    > linuxes - it is never bad in linux anyway... :)
    > You'll probably get faster NFS that way, since nfs was moved to
    > kernel level I think in 2.3 or something...

    Ok, there's actually a kernel (no pun intended) of good advice, here,
    but there's also a lot of danger in what you're saying. Here's the
    detail:

    The 2.3 series is an UNSTABLE development series. It is intended for
    kernel developers and those who want to test out new code only. The
    2.4-test series is the beta for the initial roll-out of 2.4, the next
    stable kernel series based on 2.3.

    If what you're running into is SMP-related you could very likely
    benifit from using 2.4, but IT IS ONLY IN BETA, so you would be
    crawling out on quite a limb here. At the very least, you would need
    to do some serious Q/A before deploying.

    That said, your best first step here is to see if you have the same
    problem with one processor. If you don't, you know you're running into
    the SMP/ethernet locking problem and that your only options are
    single-processor or 2.4. Check the kernel mailing list and see if I'm
    wrong. There might be other ways to address this....

    -- 
    Aaron Sherman
    Systems Architect
    HighWired.com -- The global high school community
    http://www.highwired.com
    

    300 North Beacon Street Watertown, MA 02472 (617) 926-1850 x238 (617) 926-1861 fax asherman@highwired-inc.com / ICQ#43677395 / Y!ajstrader

    "We had some good machines, but they don't work no more." -"Faded Flowers" / Shriekback



    This archive was generated by hypermail 2b29 : Sat Aug 12 2000 - 10:52:34 EDT