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On Mon, 2008-11-24 at 12:07 +0100, Dirk Heinrichs wrote: |
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> Am Montag, 24. November 2008 11:30:25 schrieb William Kenworthy: |
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> |
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> > By transient storage I mean that the data is duplicated across across |
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> > physical storage spaces so that if a machine goes down, the data is |
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> > still available. |
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> |
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> OK, thanks. |
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> |
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> > I thought Andrews FS did that, but didnt see when |
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> > looking at it yesterday. |
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> |
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> Yes, (Open-)AFS indeed does this. However, this replication is read-only. This |
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> means you can read the data as long as at least one replica is available and |
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> write the data as long as the original (the read-write) volume is available. |
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> There are also some other things to keep in mind: |
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> |
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> * AFS' primary tool for access control are its access control lists (ACL), but |
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> those are not posix, but AFS ACLs and they apply at the directory (not file) |
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> level. However, that's usually sufficient, because one can work with subdirs |
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> and symbolic links to implement more restrictive access for some files in the |
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> same directory. |
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> |
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> * ACLs can also contain host names. |
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> |
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> * If a volume is replicated, the client always prefers the read-only path |
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> (read-write volumes are usually accessed via /afs/.mycell.mydomain, while |
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> read-only volumes (if they exist) are accessed via /afs/mycell.mydomain). So |
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> if you want to modify a file you must explicitely open it via the rw-path. |
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> |
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> * Replication doesn't happen automatically, needs an explicit command. |
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> |
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> * Support for backup volumes is also there (comes with its own backup system). |
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> |
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> * Can move volumes to different servers while online. |
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> |
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> * Data is cached on the client. |
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> |
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> * You'll need Kerberos 5. |
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> |
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> If you have further questions, feel free to ask. |
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> |
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> Bye... |
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> |
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> Dirk |
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> |
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|
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Discovered this: |
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|
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http://en.wikipedia.org/wiki/List_of_file_systems#Distributed_file_systems |
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|
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Thats going to keep me busy for awhile! |
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|
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BillK |
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|
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-- |
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William Kenworthy <billk@×××××××××.au> |
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Home in Perth! |
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