Re: 20TB Storage System (fsck????)

From: Petri Helenius (pete_at_he.iki.fi)
Date: 09/03/03

  • Next message: Chuck Swiger: "Re: 20TB Storage System (fsck????)" 
    Date: Wed, 03 Sep 2003 21:22:59 +0300
To: Max Clark <max.clark@media.net>

    Max Clark wrote:

    >Ohh, that's an interesting snag. I was under the impression that 5.x w/ PAE
    >could address more than 4GB of Ram.
    >
    >
    It does. However as long as a pointer is 32 bits, your address space for
    a process
    is maxed out at 4G which translates to about 2.5G user after kernel and
    other
    things have taken their toll.

    >If fsck requires 700K for each 1GB of Disk, we are talking about 7GB of Ram
    >for 10TB of disk. Is this correct? Will PAE not function correctly to give
    >me 8GB of Ram? To check 10TB of disk?
    >
    PAE functions correctly but does not provide for 7G address space.

    >Is there anyway to bypass this requirement and split fsck into smaller
    >chunks? Being able to fsck my disk is kinda important.
    >
    >
    Yes, you do that by splitting up the filesystem to smaller filesystems.
    Kind of obvious?

    >I have zero experience with either itanium or opteron. What is the current
    >status of support for these processors in FreeBSD? What would the preferred
    >CPU be? Will there be PCI cards that I would not be able to use in either of
    >these systems?
    >
    >
    I´m personally biased towards the Opteron, but that´s more based on that
    it makes
    more sense than their technical merits so far (because neither has too
    much).

    Both CPU´s should work fine with 5.2 according to the TODO list.
    Meanwhile I suggest
    you play with the number of inodes on the 10TB filesystem and see how
    that affects
    the memory usage.

    Pete

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  • Next message: Chuck Swiger: "Re: 20TB Storage System (fsck????)"

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