Okay. Got it. Regards,
Indivar Nair On Sun, Feb 21, 2021 at 7:55 PM Spitz, Cory James <[email protected]> wrote: > Right, except I should point out that a mirror sync operation doesn’t have > to be from one pool to another. The FLR replica can use any specified > layout. Using an OST Pool is just a convenience. > > > > -Cory > > > > On 2/20/21, 12:10 PM, "Indivar Nair" <[email protected]> wrote: > > > > Thanks, Cory. > > > > So - > > > > 1. When the "lfs mirror" command is run, the file(s) are copied by the > client from one pool to another > > Pool A -> Client Machine -> Pool B (mirror) > > 2. If a mirrored file is modified, the modifications are saved only to the > primary mirror > > We will then have to run the "lfs mirror resync" command to > synchronize all the mirror copies > > Pool A (modified file) -> Client Machine -> Pool B (mirror) > > > > So for this feature to be really effective, we will need a dedicated > client that does this copying / re-copying continuously. > > And if there are a lot of mirrored files, the dedicated client will have > to be very fast too. > > > > 3. In future it may be possible to move these files using HSM agents. > > > > Regards, > > > > > > Indivar Nair > > > > On Fri, Feb 19, 2021 at 1:51 AM Spitz, Cory James <[email protected]> > wrote: > > Good questions, Indivar. > > > > 1) The Lustre Operations Manual doesn’t make this clear at > https://doc.lustre.org/lustre_manual.xhtml#flr.operations.resyncmirror , > but a mirror sync will be completed in the context of the client that it > was executed on. > > > > 2) Mirror resync is entirely manual today. Again, it is done in the > context of the client from which the lfs command was executed. Automatic > or “Immediate” mirror is on the https://www.lustre.org/roadmap/ for > 2.16.0. However, as a side note, there are also plans to “externalize” and > leverage the HSM coordinator to be able to hand-off the data movement to > multiple data movers. See LU-6081, LU-12890, and LU-13384 for an outline > of that work. I only mention it here because you’ve hinted at the need for > this improvement, but it is not committed to the roadmap yet. > > > > 3) One way could use lfs find to find files needing a mirror update. > There are multiple options to zero in on the mirror count and/or state. > Consult the lfs-find man page for details. > > > > -Cory > > > > On 2/17/21, 6:43 AM, "lustre-discuss" < > [email protected]> wrote: > > > > Hi All, > > > > I was going through the FLR feature in the Lustre Manual and had some > questions. > > > > 1. If we run the "lfs mirror" command on an existing file or directory, > how is the file ' directory copied from one OST to another? > > Is the copying done by the Lustre client on which this command was run? > > > > 2. And, in case of delayed mirroring of newly created files, who does the > copying? > > > > 3. How can we automate this process to automatically mirror certain file > types? > > > > Regards, > > > > > > Indivar Nair > > > >
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