On 24 September 2018 at 21:01, Jeevan Patnaik <[email protected]> wrote:
> Hi, > > What do you mean by expanding volume? > > I mean adding new bricks to extend storage. It is mentioned that detaching > tier is must for adding or removing bricks. > > What command did you use to detach the tier? And how did you check that > the files still exist on the hot tier? > > gluster volume tier volume_name detach start > > I check the files directly from backend filesystem on disk and there are > still left over files on all hot tier disks. > > Anyhow I proceeded with detach commit to see what would happen..so after > commit, I can't access those files from client filesystems..so they're gone > with the hot tier and were not moved to cold tier. > Did you check that the detach tier operation had completed before running detach commit? > > And even if I try to attach the hot tier bricks again to bring back the > files, attach won't work with existing files. > > So, it seems we shouldn't detach hot tier without making sure all files > are moved to cold tier..but in my case, some files just won't move, even > though they aren't being accessed anywhere. > > > There's a statement saying POSIX locks can cause files to be still left in > hot tier and in that case, either the application causing posix lock has to > be closed or files should be moved manually (but where?)... however, I > don't think in my case there's any posix locks as the files are not > accessed by any application except gluster itself. > > Regards, > Jeevan. > > > On Mon 24 Sep, 2018, 8:45 PM Nithya Balachandran, <[email protected]> > wrote: > >> It has been a while since I worked on tier but here is what I remember: >> >> >> On 24 September 2018 at 19:15, Jeevan Patnaik <[email protected]> >> wrote: >> >>> Hi Nithya, >>> >>> No..the files are not being accessed. And tiering mode is in cache mode >>> and what I understood is in cache mode every file is moved to hot tier >>> until it reaches low watermark, then it only promotes highly accessed files. >>> >>> Not quite . All files will initially exist on the cold tier. Any new >> files will be created on the hot tier. Any old files that are accessed will >> be promoted ot the hot tier. >> >> >> And do you mean everytime we expand volume, we are virtually flushing >>> the tier and it regenerates only when a files are accessed? >>> >>> What do you mean by expanding the volume? >> >> >>> Also I see one more issue now, I hav generated another 1000 files after >>> tiering is started and I see all 1000 files are now created on hot tier. >>> Now, I detached again..in detach status it shows completed..but when I >>> checked, around 260 files are still located on hot tier..those files are >>> not being used anywhere..ca you tell why are they still not moved to cold >>> tier and why the detach status is showing a wrong status. >>> >> >> What command did you use to detach the tier? And how did you check that >> the files still exist on the hot tier? >> >> Regards, >> Nithya >> >>> >>> I am using gluster 3.12.3 and server hosts include RHEL 6.7 and 7.2 >>> hosts also. >>> >>> Regards, >>> Jeevan. >>> >>> On Mon 24 Sep, 2018, 7:00 PM Nithya Balachandran, <[email protected]> >>> wrote: >>> >>>> Are those files being accessed? Tiering will only promote those that >>>> have been accessed recently. >>>> >>>> Regards, >>>> Nithya >>>> >>>> On 24 September 2018 at 18:32, Jeevan Patnaik <[email protected]> >>>> wrote: >>>> >>>>> I see it still not promoting any files. Do we need to run any command >>>>> to force the movement? >>>>> >>>>> This would be an issue if we need to expand disk as then we also need >>>>> to detach existing tier and attach again and expect the data to be >>>>> promoted >>>>> to the hot tier. >>>>> >>>>> Regards, >>>>> Jeevan. >>>>> >>>>> On Mon 24 Sep, 2018, 6:17 PM Jeevan Patnaik, <[email protected]> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I have created a 18 disk replica 3 volume and created 1000 random >>>>>> files each of 10M. >>>>>> >>>>>> Later I have attached 15 disk replica 3 tier with each hot tier disk >>>>>> coming from cold tier host, except on 3 (as we don't have hot tier disk) >>>>>> >>>>>> After attach, I see no files are promoted at even after 15 minutes. >>>>>> Status is showing as In progress. >>>>>> >>>>>> Is it always this much slow? For 10G data, 15 minutes is too much >>>>>> Also will the data try to be promoted to a hot tier coming from the >>>>>> same host to reduce the time taken to move the files? >>>>>> >>>>>> Cold tier is made of RAID supported SSD and hot tier is made of NVMe >>>>>> SSDs. >>>>>> >>>>>> >>>>>> Regards, >>>>>> Jeevan. >>>>>> >>>>> >>>>> _______________________________________________ >>>>> Gluster-users mailing list >>>>> [email protected] >>>>> https://lists.gluster.org/mailman/listinfo/gluster-users >>>>> >>>> >>>> >>
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