Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello, cLVM doesn't provide snapshots :( But you say my behaviour is "normal" ? so, why lvcreate/lvremove is not replicated ? it's not a "block" operation for the bottom layer ? And if I export a physical volume (and not a LVM one) and then after on iSCSI volume I do "lvcreate" does it solve the problem ? Regards, Olivier XO Project http://xen-orchestra.com On Sat, Mar 6, 2010 at 6:01 PM, Maros Timko <timkom at gmail.com> wrote: >> >> Message: 1 >> Date: Thu, 4 Mar 2010 17:48:24 +0100 >> From: Olivier LAMBERT <lambert.olivier at gmail.com> >> Subject: [DRBD-user] Detection of Logical Volume on nested LVM >> replication >> To: drbd-user at lists.linbit.com >> Message-ID: >> <f769216c1003040848m4b1ffaaatc15dc952781ce946 at mail.gmail.com> >> Content-Type: text/plain; charset=ISO-8859-1 >> >> Hello, >> >> I'll try to be clear, but it's really hard to explain.. >> In few words : when I create a Logical Volume on a host attached >> (iSCSI) to one DRBD server, it doesn't appear on the second host, >> attached to the other DRBD. But, on existing LV, it works like a charm >> (all data's are replicated). And more, if I create a LV on "one side", >> and fill it with data, I saw the replication link with heavy traffic, >> but always no LV. >> Now, to understand, here is how it happened with this infrastructure. >> >> 1) On both DRBD hosts : Debian GNU/Linux, Dual Primary setup, version: >> 8.3.7 (api:88/proto:86-91). I choose to configure a resource on a >> Logical volume of 500Gb (named /dev/vg0/xen). To be clear, two hosts >> are "DRBD1" & "DRBD2". a cat /proc/drbd gave this : >> 0: cs:Connected ro:Primary/Primary ds:UpToDate/UpToDate C r---- >> ns:153716 nr:408752 dw:562408 dr:355156 al:179 bm:109 lo:0 pe:0 >> ua:0 ap:0 ep:1 wo:n oos:0 >> >> >> 2) This resource is exported with iSCSI. For the example, let's say >> that CLIENT1 is connected to DRBD1, and CLIENT2 is connected to DRBD2. >> It's simplifed because in real, it's multiple Xen Dom0's clients with >> multipath (but we don't care of that here). >> >> 3) CLIENT1 see the device as a block device (so far so good, iSCSI >> works). I choose to use LVM on this block device. I create for example >> : /dev/vg_xen/mydisk on CLIENT1. I mount it, I put some stuff in there >> : I saw the replication like working : some traffic. DRBD2 and 1 says >> it's all OK. If I lvscan on CLIENT1, I can see my brand new volume. >> >> 4) CLIENT2, (so, connected on iSCSI with DRBD2), see the block device, >> the volume group, but NOT the Logical Volume. If I disconnect DRBD2's >> resource, and reconnect it, and reconnect iSCSI of CLIENT2, wow, I saw >> the LV ! >> >> And more : if the LV exists on both side (after disconnect/reconnect >> the resource), data's are correctly replicated (obviously, I do NOT >> mount LV on both side, I'm aware of that !). But, if I fill on one >> side (e.g CLIENT1), dismount it, then mount it on CLIENT2, data are >> here, without any problem. >> >> So, my "theory", is that LVM operations (lvcreate or lvremove) on a >> volume group, which is on top of iSCSI and LVM replicated device by >> DRBD, are NOT replicated, UNTIL disconnect/reconnect the ressource. I >> don't know why, and that's why I ask here to understand what I miss. > > Right. Discussed many times here and on Heartbeat/Pacemaker list. Try > to search with cLVM keyword. > >> Additional Informations: If my clients are connected to the SAME DRBD >> (let's tell DRBD1), if CLIENT1 creates a LV, CLIENT2 is immediatly >> aware of that (just inactive, not a problem, vgchange and it works). >> So the "problem" is during the replication. >> >> Thanks for your help. >> >> >> Regards, >> >> >> Olivier >> XO Project >> http://xen-orchestra.com >> > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user >