[lustre-discuss] FLR mirroring on 2.12.1-1

[Andreas Dilger]

This is definitely not the intended behavior.  Could you please file a ticket in Jira.

Cheers, Andreas

On May 20, 2019, at 07:20, John Doe <ace629426 at gmail.com> wrote:
> 
> It turns out that the read eventually finished and was 1/10th of the performance that I was expecting. 
> 
> As ost idx 1 is unavailable, the client read has to timeout on ost idx 1 and then will read from ost idx 7. This happens for each 1MB block, as I am using that as the block size. 
> 
> Is there a tunable to avoid this issue?
> 
> lfs check osts also takes about 30 seconds as it times out on the unavailable OST. 
> 
> Due to this issue, I am virtually unable to use the mirroring feature. 
> 
> 
> On Sun, May 19, 2019 at 4:27 PM John Doe <ace629426 at gmail.com> wrote:
>> After mirroring a file , when one mirror is down, any reads from a client just hangs. Both server and client are running latest 2.12.1-1. Client waits for ost idx 1 to come back online.  I am only unmounting ost idx1 not ost idx 7.
>> 
>> Has anyone tried this feature? 
>> 
>> Thanks,
>> John.
>> 
>> lfs getstripe mirror10
>> mirror10
>>   lcm_layout_gen:    5
>>   lcm_mirror_count:  2
>>   lcm_entry_count:   2
>>     lcme_id:             65537
>>     lcme_mirror_id:      1
>>     lcme_flags:          init
>>     lcme_extent.e_start: 0
>>     lcme_extent.e_end:   EOF
>>       lmm_stripe_count:  1
>>       lmm_stripe_size:   1048576
>>       lmm_pattern:       raid0
>>       lmm_layout_gen:    0
>>       lmm_stripe_offset: 1
>>       lmm_pool:          01
>>       lmm_objects:
>>       - 0: { l_ost_idx: 1, l_fid: [0x100010000:0x280a8:0x0] }
>> 
>>     lcme_id:             131074
>>     lcme_mirror_id:      2
>>     lcme_flags:          init
>>     lcme_extent.e_start: 0
>>     lcme_extent.e_end:   EOF
>>       lmm_stripe_count:  1
>>       lmm_stripe_size:   1048576
>>       lmm_pattern:       raid0
>>       lmm_layout_gen:    0
>>       lmm_stripe_offset: 7
>>       lmm_pool:          02
>>       lmm_objects:
>>       - 0: { l_ost_idx: 7, l_fid: [0x100070000:0x28066:0x0] }
> 

Cheers, Andreas
--
Andreas Dilger
Principal Lustre Architect
Whamcloud