Hi Brassow, Thanks for your review. >>> On 4/22/2015 at 05:49 AM, in message <D7A1AF2A-21CC-4B39-9221-511A312B2AA5@xxxxxxxxxx>, Brassow Jonathan <jbrassow@xxxxxxxxxx> wrote: > > On Apr 2, 2015, at 10:51 PM, Lidong Zhong <lzhong@xxxxxxxx> wrote: > > > > Currently if there is a leg failure, the bio will be put into the hold > > list until userspace replace/remove the leg. Here we are trying to make > > dm-raid1 ignore the failure and keep the following bios going on. > > This is because there maybe a temporary path failure in clvmd > > which leads to cluster raid1 remove/replace the fake device failure. And > > it takes a long time to do the full sync if we readd the device back. > > --- > > Just be aware that there are failure scenarios that this does not handle as > well. Like a reboot causing the legs to return but not the log. It’s a In this scenario the raid1 can not even get activated. I think it's beyond what dm-raid1 could proceed. > remote possibility, but something the old model considered. The new RAID > targets which leverage the MD personalities are much better (e.g. ‘lvcreate > —type raid1’), but they don’t support active-active cluster setups. > > I’ve seen a couple things on the linux-raid mailing list suggesting that > someone (Goldwyn Rodrigues) may be thinking about making RAID1/10 > cluster-aware… LVM should be able to take advantage of this if it became a > reality. > > Are you interested in providing your use-case for cluster mirroring (vs > opting for active/passive mirroring)? The most common use case would be cLCM providing shared storage with ocfs2/gfs2 running on it. Currently it's the only way to provide clustered raid1. Of course it's a better choice for what Goldwyn is doing now.But how long it will take to become stable enough. Also, the patch series would be an enhancement for dm-raid1. Regards, Lidong > > brassow > > -- > dm-devel mailing list > dm-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/dm-devel -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
