Re: md raid1 passes barriers, but xfs doesn't use them?

[Eric Sandeen <sandeen@sandeen.net>]

Martin Steigerwald wrote:
> Hi Eric!
> 
> Am Dienstag 24 Juni 2008 schrieb Eric Sandeen:
>> So md raid1 is happy to pass down any barrier writes that it sees, but
>> this bit in xfs_mountfs_check_barriers() at mount time:
> 
> Interesting. Since when?

Which part?  :)  XFS has done the flag check for a very long time...

> On my last test also ext3 disabled barries over device mapper / 
> reiserfs[1]. well but I used it with LVM, maybe its different with RAID 
> 1. I thought this to be a generic device mapper issue.
> 
> Did you test with ext3 too?

This is xfs-specific; ext3 does not look for the queue ordered flag so
won't have this problem on md raid1.

> [1] http://bugzilla.kernel.org/show_bug.cgi?id=9554

but that's for device-mapper, which has never supported barriers ....
I'm talking about md raid1 here (not dm).

-Eric

> Ciao,