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No, it's completely unrelated.No, it's completely unrelated.Posted Jun 4, 2009 7:06 UTC (Thu) by bronson (subscriber, #4806)In reply to: No, it's completely unrelated. by drag Parent article: Xen again
> 9pnet_virtio
Wow, people are still writing 9p code? Given the sad state of http://sourceforge.net/projects/v9fs and http://sourceforge.net/projects/npfs I thought that these projects were stone dead.
I'd really like a network filesystem that is easier to administer than NFS and CIFS... Tried DRBD but didn't like it much. Is v9fs worth a look?
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No, it's completely unrelated. Posted Jun 4, 2009 12:03 UTC (Thu) by drag (subscriber, #31333) [Link]
No clue about plan9.
But DRBD is a way of keeping volumes in sync, not so much a file system.
The easiest FS to administer that I know of is sshfs. I use it heavily and it is stable and actually very fast. It can beat NFS even sometimes.. And all you need is Openssh server running and a fuse support in the client. The ssh server is the real gauge on how well sshfs works. Anything other then a relatively recent version of OpenSSH and I doubt the results will be that good.
But if DRBD was even being considured then your needs are going to be specialized. Other alternative to look at could possibly be Redhat's GNBD from GFS or ISCSI.
No, it's completely unrelated. Posted Jun 4, 2009 19:32 UTC (Thu) by bronson (subscriber, #4806) [Link]
Tried sshfs 5 or so years ago, rejected it because the crypto overhead prevented me from filling a 100 MBit link. I should probably try it again since that won't be a problem nowadays.
I only mentioned DRBD to illustrate how desperate I've become! It was actually pretty good except that I couldn't get the split brain recovery to work the way I wanted. So close and yet so far. Haven't gotten desperate enough to try AFS yet!
Why doesn't 9p or webdav or some simple protocol take off? It's amazing to me that NFS and CIFS are still state of the art. I guess I don't understand the trade-offs very well.
No, it's completely unrelated. Posted Jun 4, 2009 20:20 UTC (Thu) by drag (subscriber, #31333) [Link]
For sshfs if you want to have good performance you need to disable compression. If you think the crypto has to much overhead then change the encryption method to RC4.
Very likely you were running something like 3DES that has very high overhead. And like I said you need to have a relatively recent version of OpenSSH (say a version from the past 2 years or so) for reliable service.
You can set these on a per server basis in your ~/.ssh/config
I have had no problem personally beating NFS when it comes to my personal usage at home over wireless and gigabit link.. although of course this sort of thing is not suitable for large numbers of users.
:)
No, it's completely unrelated. Posted Jun 4, 2009 14:08 UTC (Thu) by sbergman27 (guest, #10767) [Link]
My understanding is that the main thrust of the the 9p virtio stuff is to implement shared volumes without all the ugly network guts being exposed to the administrator. And hopefully, at lower latency than the rather significant local latencies one sees even using a virtio network driver.
I have an ugly situation where I have a (proprietary) cobol C/ISAM <-> SQL gateway to some cobol accounting files. Due to the brain-deadness of the proprietary vendor (political concerns, their licenscing with their Cobol runtime supplier, yadda, yadda, yadda...), I have to run it virtualized in an old distro and it sees the C/ISAM files via NFS4. It's written to do a lot of fsync'ing and doesn't seem to make any use of any sort of NFS caching, and so latency absolutely kills its performance. I can't use any of the virtio stuff because the guest kernel is too old to support it, and even that has latencies in the hundreds of microseconds. So I'm using the software emulated E1000 driver, which is almost as efficient as virtio.
However, if I could use the 9p shared volume stuff, I suspect, but am not sure, that latency would be much improved. As it stands, it is still over twice as fast as running on a separate machine via NFS4 over 1000baseT.
So far as I know, the 9p-virtio thing is still an active project, but not yet in mainline KVM. Or, at least, it does not seem to be in Ubuntu 9.04 server.
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