On Jul 14, 2009, at 11:02 AM, Hans de Goede wrote:
Hi, On 07/14/2009 03:39 PM, Doug Ledford wrote:On Jul 14, 2009, at 6:59 AM, Hans de Goede wrote:Hi, As you probably know I'm working on making Fedora 12 use mdraid instead of dmraid for Intel BIOS-RAID setups. The installer (anaconda) part is mostly done (needs more testing) and now I'm looking at implementing support for this in dracut (the new mkinitrd for Fedora 12). So I've been testing how this works for both imsm mdraid sets and native mdraid metadata sets, in both cases using a 2 disk mirror, so that the set can also be brought up in degraded mode. Currently the udev rules use incremental assembly like this: mdadm -I /dev/mdraid-memberHmmm...does dracut use udev during initramfs time?Yes, it uses udev for everything, making discovery of / consistent with the discovery of other storage devices.
I'm not sure I like or agree with that philosophy. I absolutely *don't* want my / filesystem or raid device treated like some plug in, temporary, roaming raid device. They *aren't* the same, not in terms of importance to the running of the machine and not in terms of reliability requirements. By using mdadm -A in the mkinitrd calls, I was able to put in an mdadm.conf file and limit what arrays get started to arrays found non-ambiguously in that mdadm.conf file and identified by UUID. When you switch to incremental assembly for root, you risk the possibility of name space collisions and non- deterministic bring up of your / array.
<snip>Are we going to be totally changing this withdracut and F12? This method very nicely resolves the issues you posted.Yes. Regards, Hans
-- Doug Ledford <dledford@xxxxxxxxxx> GPG KeyID: CFBFF194 http://people.redhat.com/dledford InfiniBand Specific RPMS http://people.redhat.com/dledford/Infiniband
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