Folks, Yesterday Andreas Dilger wrote: > On Sep 10, 2008 18:05 +0200, Tobias Oetiker wrote: > > I have not tested this, but since we are putting about 16 different > > journals on this one ssd, I would assume that the loss through > > seeking between the journals would be pretty bad, and again bring > > back that inter-filesystem-dependency we were trying to loose with > > this measure. > > The cost of putting the journals on 16 separate, relatively small > disk devices would probably be comparable to the cost of the SSD > and not have a single point of failure. The journal does mostly > linear IO, so performance is probably equal or better. You are telling me things that I am aware of. The reason I wrote to this group is to figure what would happen to an ext3 fs when the external journal was lost, especially what happens when it is lost on a filesystem where 'data=journal' is set. Because if it is catastrophic, then it basically means that the journal has to reside on a device that is as secure as to rest of the data, meaning that if the data is on RAID6 then the journal should be on RAID6 too. What I am hoping for, is that someone tells me, that in the case of 'data=journal' the loss would only be the material that is still in the journal (eg 30 seconds worth of data) and the rest of the fs would have a fair chance of being recoverd with fsck. cheers tobi -- Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland http://it.oetiker.ch tobi@xxxxxxxxxx ++41 62 775 9902 / sb: -9900 _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
