Messages in this thread |  | | From | (Steffen Grunewald) | Subject | Re: Drawbacks of implementing undelete entirely in user | Date | Tue, 25 Jun 1996 15:14:03 +0200 (MET DST) |
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"Bob Allison writes" |> |> I have a couple of file servers here made by a company called Network Appliance. |> They have a feature called "snapshot" which seems to do everything about |> undelete and more. |> [...] |> |> I'm not really sure of the kernel/user separation of this idea, but I think the |> only kernel support that would be needed would be to not deallocate blocks until |> all files in all snapshots are no longer referencing the block. Creating and |> deleting snapshots could probably be done in user space from a cron job. |> So it's doing sth. like hardlinking all files, right ? Then kernel support is already available. As long as the link count stays above zero the file can be accessed.
|> (BTW, making a snapshot of my 32GB file system (all drives form a single RAID |> array) takes about 15-30 seconds.) |> Sounds quite fast to me. But then, all the information should be in the cache of the system already. Maybe it's a special feature of your RAID array ? -- Steffen Grunewald | email steffen@gfz-potsdam.de | fax (+49)-331-8877 520 GeoForschungsZentrum Potsdam, Telegrafenberg A17, D-14473 Potsdam, Germany /* Disclaimer : I don't speak for my employers, they don't speak for me */
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