Date: Thu, 19 Apr 2001 10:58:50 -0600 From: Warner Losh <imp@harmony.village.org> To: Darryl Okahata <darrylo@soco.agilent.com> Cc: freebsd-small@FreeBSD.ORG Subject: Re: The ultimate board! Message-ID: <200104191658.f3JGwo804947@harmony.village.org> In-Reply-To: Your message of "Thu, 19 Apr 2001 09:44:44 PDT." <200104191644.JAA12824@mina.soco.agilent.com> References: <200104191644.JAA12824@mina.soco.agilent.com>
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In message <200104191644.JAA12824@mina.soco.agilent.com> Darryl Okahata writes: : Warner Losh <imp@harmony.village.org> wrote: : : > : Does the IBM microdrive work (it's got a CF interface)? I'm : > : interested, but I'd be more interested if the microdrive could be used : > : (like everyone else, I'd really like to make a "low-power" router with a : > : DHCP server that handles mac addresses). : > : > Yes, but 64M CF parts are cheaper and more reliable. : : True, but the idea that a CF-based router *WILL* fail is, well, : distasteful. : : [ The DHCP server keeps the leases on disk. In an home environment, it : should be possible to use a CF card, as clients don't come and go all : that often, but I don't know enough about FFS to be sure. ] : : [ Heh. Commercial entities would call this, "planned obsolescence". ;-) ] CF parts have 10e5 to 10e6 writes per block typically. You would have to do a lot of writes to the CF to wear it out. And we've found that in hostile environments, the CF have been much more reliable than the IDE hard disks they replaced. Even if it was an issue, you could keep the leases on /tmp (make it MFS) and then run a script once an hour to write it to the CF. Ditto at shutdown. I once calculated that at 1 write per hour, the CF parts that I was evaluating would last on the order of 1000s years (based only on the wear of the flash parts). Based on 10e5 writes per block, 8k blocks and 5M of available space, 1 write per second is about 723 days, assuming even wear on each of the available blocks (unless I've messed up my calculations). That puts it at two years. one write per minute would be 120 years and one write per hour would be 7200 years. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message
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