(reiserfs) Re: AIX JFS dual-mount (fwd)
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-------- Original Message --------
Date: Sat, 29 Jan 2000 09:54:03 -0800
From: "Peter C. Norton" <[email protected]>
Subject: Re: [linux-lvm] Re: (reiserfs) Re: AIX JFS dual-mount
Message-ID: <[email protected]>
References: <[email protected]> <[email protected]>
In-Reply-To: <[email protected]>; from [email protected] on Sat, Jan 29, 2000 at 12:14:49AM -0800
GFS seems to require some support from hardware in the way of "dlocks", a
not-too widely supported standard. I think you'd need to have drives that
implement dlocks, and that the lvm would have to know about them. What
would need to be done to the volume stuff to support dlocks? Could any
filesystem be built on top of a volume manager with dlock support?
-Peter
Quoted 32 lines · Tracy R Reed
Quoted 6 lines · Chris Mason
Quoted 5 lines · Russell Coker
A colleague told me that with AIX machines you can have two systems mount the same file system, they then lock the bus whenever they need to do updates.
Can this give usable write performance? If so is it worth considering?
Quoted 8 lines
Only if you also include some kind of lock manager. Without it, the two boxes would have no way if knowing if and when their caches are still valid.
Once you have the lock manager, you don't need the full device lock, the systems can coordinate who is writing/reading which blocks.
Anybody know exactly what AIX provides here?
Sounds similar to GFS (which I only recently learned about and find totally amazing and plan to play with soon and perhaps implement it in a production environment if it is all it's cracked up to be) only not over fibrechannel. It does fine grain locking, manages cache coherency, the works:
www.globalfilesystem.org
I've been meaning to mention this to you guys and make sure everyone was aware of it. It is a journalling filesystem while allows multiple hosts to mount the same filesystem at the same time. I hope to see a lot of integration between reiserfs, GFS, LVM, and MD in the future. There is currently a lot of overlap in these areas. Linux needs all of these features to be smoothly integrated and very stable if it is going to go head to head with the big boys someday.
--
Tracy Reed http://www.ultraviolet.org
Signature · 3 lines
The 5 year plan: In five years we'll make up another plan. Or just re-use this one.