Andy Smith <andy@xxxxxxxxxxxxxx> wrote: > [-- text/plain, encoding quoted-printable, charset: us-ascii, 20 lines --] > > On Tue, Jan 04, 2005 at 01:22:56PM +1100, Neil Brown wrote: > > On Monday January 3, ewan.grantham@xxxxxxxxx wrote: > > > I've setup a RAID-5 array using two internal 250 Gig HDs and two > > > external 250 Gig HDs through a USB-2 interface. Each of the externals > > > is on it's own card, and the internals are on seperate IDE channels. > > > > > > I "thought" I was doing a good thing by doing all of this and then > > > setting them up using an ext3 filesystem. > > > > Sounds like a perfectly fine setup (providing always that external > > cables are safe from stray feet etc). > > > > No need to change anything. > > Except that Peter says that the ext3 journals should be on separate > non-mirrored devices and the reason this is not mentioned in any > documentation (md / ext3) is that everyone sees it as obvious. No, I dont say the "SHOULD BE" is obvious. I say the issues are obvious. The "should be" is up to you to decide, based on the obvious issues involved :-). > Whether it is true or not it's clear to me that it's not obvious to > everyone. It's not obvious to anyone, where by "it" I mean whether or not you "should" put a journal on the same raid device. There are pros and cons. I would not. My reasoning is that I don't want data in the journal to be subject to the same kinds of creeping invisible corruption on reboot and resync that raid is subject to. But you can achieve that by simply not putting data in the journal at all. But what good does the journal do you then? Well, it helps you avoid an fsck on reboot. But do you wantto avoid an fsck? And reason onwards ... I won't rehash the arguments. Peter - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
