Hard disk write cache enabled safe for a router system?



  • Hi,

    I was wondering why the hard disk write cache is enabled by default, write performance shouldn't be really important on a router system? So how reliable is it on a sudden power outage or other crash with this enabled, wouldn't that (possibly/probably) corrupt the filesystem?

    I saw that in the end of 2007 a patch was applied to disable the hdd write cache by default (hw.ata.wc=0 in /boot/loader.conf), but that has apparently been removed later, as it's no longer there. What is the reason for that? Are there any downsides disabling the cache other than somewhat slower rule savings?

    Thanks.

    Joost


  • Rebel Alliance Developer Netgate

    In the git repo, the hw.ata.wc=0 line is still there. Somehow, that isn't staying on a live system.

    It should have:

    $ cat loader.conf
    hw.ata.atapi_dma="0"
    hw.ata.ata_dma="0"
    loader_color="YES"
    hw.ata.wc="0"
    kern.ipc.nmbclusters="0"
    beastie_disable="NO"
    vm.kmem_size="435544320"
    vm.kmem_size_max="535544320"
    

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