I have sent the log file to you in a separate email. Note - I read four 1MB blocks, the first two 1MB blocks were cached.
On Fri, May 24, 2019 at 1:01 AM Jinshan Xiong <[email protected]> wrote: > hmm.. This definitely is not expected. As long as ost 1 is down, it should > be returned immediately from OSC layer and tries to read the 2nd mirror > that is located on ost 7. For the following blocks, it should not even try > ost1 but go to 7 directly. > > Would you please collect Lustre log and send it to me? You can collect > logs on client side as follows: > 0. create mirrored file > 1. lctl set_param debug=-1 && lctl clear > 2. lctl mark "======= start ========" > 3. read the file > 4. lctl dk > log.txt > > and send me the log.txt file. If you can reproduce this problem > consistently, please use a small file so that it would be easier to check > the log. > > Jinshan > > On Mon, May 20, 2019 at 6:20 AM John Doe <[email protected]> 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. >> >> I >> >> On Sun, May 19, 2019 at 4:27 PM John Doe <[email protected]> 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] } >>> >> _______________________________________________ >> lustre-discuss mailing list >> [email protected] >> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org >> >
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