| Faeandar 2007-06-11, 1:14 am |
| On Mon, 11 Jun 2007 03:41:39 +0400, "Maxim S. Shatskih"
<maxim@storagecraft.com> wrote:
>
>In Windows, the block level backup speed is NOT related to number of files on
>the volume.
>
>The reason is that in Windows, such backup has no need to enumerate the files.
>There is FSCTL_GET_VOLUME_BITMAP call which allows to enumerate the _busy
>blocks on the volume_, regardless of to what file do they belong.
>
>When I saw Linux last time (early 2000ies), it only had FIBMAP IOCTL which is
>the same as Windows's FSCTL_GET_RETRIEVAL_POINTERS - get the disk block number
>for a file offset. As about FSCTL_GET_VOLUME_BITMAP - it was absent in Linux.
I was not referring to block level backups. Snapshot to tape from
NetApp for a volume level backup is lightning fast and will push tape
to it's max instantly, and keep it there.
But when you want to backup *files* you have to enumerate and match
inodes and files to blocks. That is where it matters not at all what
file system you have, you are borked.
~F
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