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    SubjectRe: the " 'official' point of view" expressed by kernelnewbies.org regarding reiser4 inclusion
    Adrian Ulrich schrieb am 2006-07-31:

    > > > And EXT3 imposes practical limits that ReiserFS doesn't as well. The big
    > > > one being a fixed number of inodes that can't be adjusted on the fly,
    > >
    > > Right. Plan ahead.
    >
    > Ok: Assume that i've read the mke2fs manpage and added more inodes to
    > my filesystem.
    >
    > So: What happens if i need to grow my filesystem by 200% after 1-2
    > years? Can i add more inodes to Ext3 on-the-fly ?

    Since you "grow", you'll be using resize2fs (or growfs or mkfs -G for
    UFS). resize2fs and the other tools do exactly that: add inodes - and
    you could easily have told this either from reading the resize2fs code
    or just trying it on a temp file:

    -- create file system
    dd if=/dev/zero of=/tmp/foo bs=1k count=50000
    /sbin/mke2fs -F -j /tmp/foo

    -- check no. of inodes
    /sbin/tune2fs -l /tmp/foo | grep -i inode | head -2
    # Inode count: 12544
    # Free inodes: 12533

    -- resize
    /sbin/e2fsck -f /tmp/foo
    dd if=/dev/zero bs=1k count=50000 >>/tmp/foo
    /sbin/resize2fs /tmp/foo

    -- check no. of inodes
    /sbin/tune2fs -l /tmp/foo | grep -i inode
    # Inode count: 23296
    # Free inodes: 23285

    Trying the same after mke2fs -b 1024 -i 1024 shows that the inode
    density will continue to be respected.

    FreeBSD 6.1's growfs(8) increases the number of inodes. This is
    documented to work since 4.4.

    Solaris 8's mkfs -G also increases the number of inodes and apparently
    also works for mounted file systems.

    This looks rather like an education issue rather than a technical limit.

    > A filesystem with a fixed number of inodes (= not readjustable while
    > mounted) is ehr.. somewhat unuseable for a lot of people with
    > big and *flexible* storage needs (Talking about NetApp/EMC owners)

    Which is untrue at least for Solaris, which allows resizing a life file
    system. FreeBSD and Linux require an unmount.

    > Why are a lot of Solaris-people using (buying) VxFS? Maybe because UFS
    > also has such silly limitations? (..and performs awkward with trillions
    > of files..?..)

    Well, such "silly limitations"... looks like they are mostly hot air
    spewn by marketroids that need to justify people spending money on their
    new filesystem.

    The only problem remains if you grossly overestimate the average file
    size and with it underestimate the number of inodes needed. But even
    then, I'd be interested to know if that's a real problem for systems
    such as ZFS.

    --
    Matthias Andree
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