From: Jamie Lokier <jamie@shareable.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Benny Halevy <bhalevy@panasas.com>,
Boaz Harrosh <bharrosh@panasas.com>,
open-osd development <osd-dev@open-osd.org>,
Avishay Traeger <avishay@gmail.com>,
Jeff Garzik <jeff@garzik.org>,
Andrew Morton <akpm@linux-foundation.org>,
Al Viro <viro@ZenIV.linux.org.uk>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [osd-dev] [PATCH 1/9] exofs: osd Swiss army knife
Date: Tue, 13 Jan 2009 15:09:55 +0000 [thread overview]
Message-ID: <20090113150955.GA9636@shareable.org> (raw)
In-Reply-To: <20090113135526.28730314@lxorguk.ukuu.org.uk>
Alan Cox wrote:
> > > +#define EXOFS_SUPER_ID 0x10000 /* object ID for on-disk superblock */
>
> And if an OS failure breaks the super block and you have only one how do
> you recover it ?
Having one super block would be silly.
But aren't most kinds of replication better done behind the OSD level,
on the storage fabric? OSD is all about letting the fabric decide
things like allocation and durability strategies after all.
With multiple super blocks at the filesystem level, some OS failures
that would trash one of the super blocks would simply trash all the copies.
I wonder how much less likely trashing one super block object than
trashing a set of them would be.
-- Jamie
next prev parent reply other threads:[~2009-01-13 15:10 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-16 14:48 [PATCHSET 0/9] exofs (was osdfs) Boaz Harrosh
2008-12-16 14:52 ` [PATCH 1/9] exofs: osd Swiss army knife Boaz Harrosh
2008-12-29 20:29 ` Andrew Morton
2008-12-31 15:33 ` Boaz Harrosh
2008-12-31 19:26 ` Andrew Morton
2009-01-01 14:44 ` Boaz Harrosh
2009-01-02 16:52 ` Pavel Machek
2009-01-04 8:43 ` Boaz Harrosh
2009-01-04 20:03 ` Pavel Machek
2009-01-05 9:01 ` Boaz Harrosh
2009-01-05 9:36 ` Pavel Machek
2008-12-16 15:15 ` Boaz Harrosh
2009-01-07 15:47 ` [osd-dev] " Benny Halevy
2009-01-13 13:55 ` Alan Cox
2009-01-13 14:43 ` Boaz Harrosh
2009-01-13 14:52 ` Boaz Harrosh
2009-01-13 15:09 ` Jamie Lokier [this message]
2009-01-13 15:17 ` Jeff Garzik
2009-01-13 15:28 ` Benny Halevy
2008-12-16 15:17 ` [PATCH 2/9] exofs: file and file_inode operations Boaz Harrosh
2008-12-29 20:34 ` Andrew Morton
2008-12-31 15:36 ` Boaz Harrosh
2008-12-16 15:21 ` [PATCH 3/9] exofs: symlink_inode and fast_symlink_inode operations Boaz Harrosh
2008-12-29 20:35 ` Andrew Morton
2008-12-16 15:22 ` [PATCH 4/9] exofs: address_space_operations Boaz Harrosh
2008-12-29 20:45 ` Andrew Morton
2008-12-31 15:35 ` Boaz Harrosh
2008-12-16 15:28 ` [PATCH 5/9] exofs: dir_inode and directory operations Boaz Harrosh
2008-12-29 20:47 ` Andrew Morton
2008-12-31 15:33 ` Boaz Harrosh
2008-12-16 15:31 ` [PATCH 6/9] exofs: super_operations and file_system_type Boaz Harrosh
2008-12-17 22:23 ` Marcin Slusarz
2008-12-18 8:41 ` Boaz Harrosh
2008-12-29 20:50 ` Andrew Morton
2008-12-16 15:33 ` [PATCH 7/9] exofs: mkexofs Boaz Harrosh
2008-12-29 20:14 ` Andrew Morton
2008-12-31 15:19 ` Boaz Harrosh
2008-12-31 15:57 ` James Bottomley
2009-01-01 9:22 ` [osd-dev] " Benny Halevy
2009-01-01 9:54 ` Jeff Garzik
2009-01-01 14:23 ` Benny Halevy
2009-01-01 14:28 ` Matthew Wilcox
2009-01-01 18:12 ` Jörn Engel
2009-01-01 23:26 ` J. Bruce Fields
2009-01-02 7:14 ` Benny Halevy
2009-01-04 15:20 ` Boaz Harrosh
2009-01-04 15:38 ` Christoph Hellwig
2009-01-12 18:12 ` James Bottomley
2009-01-12 19:23 ` Jeff Garzik
2009-01-12 19:56 ` James Bottomley
2009-01-12 20:22 ` Jeff Garzik
2009-01-12 23:25 ` James Bottomley
2009-01-13 13:03 ` [osd-dev] " Benny Halevy
2009-01-13 13:24 ` Jeff Garzik
2009-01-13 13:32 ` Benny Halevy
2009-01-13 13:44 ` Jeff Garzik
2009-01-13 14:03 ` Alan Cox
2009-01-13 14:17 ` Jeff Garzik
2009-01-13 16:14 ` Alan Cox
2009-01-13 17:21 ` Boaz Harrosh
2009-01-21 18:13 ` Jeff Garzik
2009-01-21 18:44 ` Boaz Harrosh
2009-01-12 22:48 ` Jamie Lokier
2009-01-06 8:40 ` Andreas Dilger
2008-12-31 19:25 ` Andrew Morton
2009-01-01 13:33 ` Boaz Harrosh
2009-01-02 22:46 ` James Bottomley
2009-01-04 8:59 ` Boaz Harrosh
2008-12-16 15:36 ` [PATCH 8/9] exofs: Documentation Boaz Harrosh
2008-12-18 7:47 ` Pavel Machek
2008-12-18 8:32 ` Boaz Harrosh
2008-12-16 15:38 ` [PATCH 9/9] fs: Add exofs to Kernel build Boaz Harrosh
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