[lustre-discuss] PFL not working on 2.10 client

[Andreas Dilger]

Rick,
Does this still fail with 2.10.1 or a later client?  It may just be a bug in "lfs" or the client, not an interop problem per-se. If it doesn't fail with a newer client then it probably isn't worthwhile to track down. 

If you _really_ need to get this working with the 2.10.0 client you could try the "lfs" binary (and possibly liblustreapi.so) from a newer client. Otherwise, upgrading the kernel modules to 2.10.0+patch is not much different than upgrading to 2.10.6 or 2.10.7 to fix this problem. 

Cheers, Andreas

On Apr 22, 2019, at 15:15, Mohr Jr, Richard Frank <rmohr at utk.edu> wrote:
> 
> 
> I was trying to play around with some PFL layout today, and I ran into an issue.  I have a file system running Lustre 2.10.6 and a client with 2.10.0 installed.  I created a PFL with this command:
> 
> [rfmohr at sip-login1 rfmohr]$ lfs setstripe -E 4M -c 2 -E 100M -c 4 comp_file
> 
> It did not return any errors, so I tried to query the layout:
> 
> [rfmohr at sip-login1 rfmohr]$ lfs getstripe comp_file
> comp_file has no stripe info
> 
> And if I write any data to it, I end up with a file that uses the system’s default stripe count:
> 
> [rfmohr at sip-login1 rfmohr]$ dd if=/dev/zero of=comp_file bs=1M count=50
> 50+0 records in
> 50+0 records out
> 52428800 bytes (52 MB) copied, 0.0825892 s, 635 MB/s
> 
> [rfmohr at sip-login1 rfmohr]$ lfs getstripe comp_file
> comp_file
> lmm_stripe_count:  1
> lmm_stripe_size:   1048576
> lmm_pattern:       1
> lmm_layout_gen:    0
> lmm_stripe_offset: 3
>    obdidx         objid         objid         group
>         3            265665          0x40dc1                 0
> 
> I could not find a JIRA ticket that looked similar to this. Is this a known bug?  Or some odd interop issue?  When I tried the command on another file system that uses 2.10.3 on the servers and clients, I got the expected behavior:
> 
> -bash-4.2$ lfs setstripe -E 4M -c 2 -E 64M -c 4 comp_file
> 
> -bash-4.2$ lfs getstripe comp_file
> comp_file
>  lcm_layout_gen:  2
>  lcm_entry_count: 2
>    lcme_id:             1
>    lcme_flags:          init
>    lcme_extent.e_start: 0
>    lcme_extent.e_end:   4194304
>      lmm_stripe_count:  2
>      lmm_stripe_size:   1048576
>      lmm_pattern:       1
>      lmm_layout_gen:    0
>      lmm_stripe_offset: 6
>      lmm_objects:
>      - 0: { l_ost_idx: 6, l_fid: [0x100060000:0x8f84d:0x0] }
>      - 1: { l_ost_idx: 7, l_fid: [0x100070000:0x8f72d:0x0] }
> 
>    lcme_id:             2
>    lcme_flags:          0
>    lcme_extent.e_start: 4194304
>    lcme_extent.e_end:   67108864
>      lmm_stripe_count:  4
>      lmm_stripe_size:   1048576
>      lmm_pattern:       1
>      lmm_layout_gen:    65535
>      lmm_stripe_offset: -1
> 
> --
> Rick Mohr
> Senior HPC System Administrator
> National Institute for Computational Sciences
> http://www.nics.tennessee.edu
> 
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