[LU-12328] FLR mirroring on 2.12.1-1 not usable if OST is down

• Type: Bug
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.13.0, Lustre 2.12.4
• Affects Version/s: Lustre 2.12.1
• Environment: RHEL 7.6
• Severity: 3
• Assignee: Zhenyu Xu
• Reporter: Joe Frith

Description

See below for stripe details on the file "mirror10". If OST idx 1 is unmounted and made unavailable, performance drops down to 1/10th of expected performance. The client has to timeout on OST idx1 before it tries to read from OST idx 7. This happens for each 1MB block as that is the block size being used resulting in very poor performance. 

 

 

$ 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] }

Issue Links

• is related to: LU-12525 sanity-flr test 200 and others asertion in osc_page_delete
• is related to: LU-7236 OST connect and disconnect on demand