Takahiro Yasui [tyasui@xxxxxxxxxx] wrote: > > Not really. What I meant is re-integrating a failed log device when it > > comes back again. That is also what I mean by handling 'transient > > errors'. > > Thanks, I see your requirement on this feature. > Let me put one more question. > > LVM mirroring is used to make system available even if some devices, > such as data and log device, have a problem. Currently, activations > by "vgchange -ay" command seem to fail during system booting if one > of devices related to VG are missing or had I/O error. For example, > if a mirror is structured by two data devices and log devices, the > mirror logical device should be activated and used even if one data > device and one log device are missing. > > Could you give me an idea or solution to handle this? Do we need to > enhance your feature to achieve this requirement? The requirement you are asking is more than "mirrored log" support. Actually it is nothing to do with "mirrored log" support! LVM has "--partial' option but that creates read-only volumes. IBM has implemented "--partial-rw" that activates such mirror devices. Essentially it creates an 'error device' in place of a missing device, but the patch isn't complete as it doesn't work well with other segment (target) types! What we need is changes to LVM "--partial" code path where it can create volumes read-only or read-write based on what is available instead of blindly doing read-only. Thank you for looking at these enterprise level features. Thanks, Malahal. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
