Hi, can the cephfs "max_file_size" setting be changed at any point in the lifetime of a cephfs? Or is it critical for existing data if it is changed after some time? Is there anything to consider when changing, let's say, from 1TB (default) to 4TB ? We are running the latest Nautilus release, BTW. Thanks in advance Dietmar
Hi,
On 23 May 2023, at 13:27, Dietmar Rieder <dietmar.rieder@i-med.ac.at> wrote:
can the cephfs "max_file_size" setting be changed at any point in the lifetime of a cephfs? Or is it critical for existing data if it is changed after some time? Is there anything to consider when changing, let's say, from 1TB (default) to 4TB ?
We are running the latest Nautilus release, BTW.
It's safe to set this option for any time. We have one project where max_file_size set to 70368742400000 - everything works as expected k
On 5/23/23 15:53, Konstantin Shalygin wrote:
Hi,
On 23 May 2023, at 13:27, Dietmar Rieder <dietmar.rieder@i-med.ac.at> wrote:
can the cephfs "max_file_size" setting be changed at any point in the lifetime of a cephfs? Or is it critical for existing data if it is changed after some time? Is there anything to consider when changing, let's say, from 1TB (default) to 4TB ?
We are running the latest Nautilus release, BTW.
It's safe to set this option for any time. We have one project where max_file_size set to 70368742400000 - everything works as expected
Thanks for your answer Dietmar
On Tue, May 23, 2023 at 3:28 AM Dietmar Rieder <dietmar.rieder@i-med.ac.at> wrote:
Hi,
can the cephfs "max_file_size" setting be changed at any point in the lifetime of a cephfs? Or is it critical for existing data if it is changed after some time? Is there anything to consider when changing, let's say, from 1TB (default) to 4TB ?
Larger files take longer to delete (the MDS has to issue a delete op on every one of the objects that may exist), and longer to recover if their client crashes and the MDS has to probe all the objects looking for the actual size and mtime. This is all throttled so it shouldn't break anything, we just want to avoid the situation somebody ran into once where they accidentally created a 1 exabyte RBD on their little 3-node cluster and then had to suffer through "deleting" it. :D -Greg
We are running the latest Nautilus release, BTW.
Thanks in advance Dietmar _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
On 5/23/23 15:58, Gregory Farnum wrote:
On Tue, May 23, 2023 at 3:28 AM Dietmar Rieder <dietmar.rieder@i-med.ac.at> wrote:
Hi,
can the cephfs "max_file_size" setting be changed at any point in the lifetime of a cephfs? Or is it critical for existing data if it is changed after some time? Is there anything to consider when changing, let's say, from 1TB (default) to 4TB ?
Larger files take longer to delete (the MDS has to issue a delete op on every one of the objects that may exist), and longer to recover if their client crashes and the MDS has to probe all the objects looking for the actual size and mtime. This is all throttled so it shouldn't break anything, we just want to avoid the situation somebody ran into once where they accidentally created a 1 exabyte RBD on their little 3-node cluster and then had to suffer through "deleting" it. :D -Greg
Thanks for your detailed explanation. Would it also be ok if we set the max to 5 TB create some big files (>1TB) and then set the max back to 1 TB? Would the big files then still be available and usable? Best Dietmar
On Tue, May 23, 2023 at 11:52 PM Dietmar Rieder <dietmar.rieder@i-med.ac.at> wrote:
On 5/23/23 15:58, Gregory Farnum wrote:
On Tue, May 23, 2023 at 3:28 AM Dietmar Rieder <dietmar.rieder@i-med.ac.at> wrote:
Hi,
can the cephfs "max_file_size" setting be changed at any point in the lifetime of a cephfs? Or is it critical for existing data if it is changed after some time? Is there anything to consider when changing, let's say, from 1TB (default) to 4TB ?
Larger files take longer to delete (the MDS has to issue a delete op on every one of the objects that may exist), and longer to recover if their client crashes and the MDS has to probe all the objects looking for the actual size and mtime. This is all throttled so it shouldn't break anything, we just want to avoid the situation somebody ran into once where they accidentally created a 1 exabyte RBD on their little 3-node cluster and then had to suffer through "deleting" it. :D -Greg
Thanks for your detailed explanation.
Would it also be ok if we set the max to 5 TB create some big files (>1TB) and then set the max back to 1 TB? Would the big files then still be available and usable?
It does look like that would work, but I wouldn't recommend it. Workarounds like that will always be finicky. -Greg
Best Dietmar
participants (3)
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Dietmar Rieder
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Gregory Farnum
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Konstantin Shalygin