Andreas, Thanks for the update. I should point out that the documentation for -C is incorrect in that it states all the OSTs in the file system will be used, but in actuality it is all the OSTs in the selected pool will be used. John
Sent from my iPhone > On May 17, 2024, at 11:37 AM, Andreas Dilger <[email protected]> wrote: > > There is a patch inflight that adds "-C -N" -> "N stripes per OST", N <= > 32. This also changes "-C -1" to be the same as "-c -1" (ie. 1-stripe per > OST), which was discussed and decided to be the more sensible option than > using 2000 stripes for a file. If there is a need for a 2000-stripe file, "-C > 2000" can still be used. > > https://review.whamcloud.com/54192 > > Cheers, Andreas > >>> On May 17, 2024, at 17:32, Nathan Dauchy via lustre-discuss >>> <[email protected]> wrote: >>> >> >> John, >> >> I believe the lfs-setstripe man page is incorrect (or at least misleading) >> in this case. I recall seeing 2000 hardcoded as a maximum, so it appears to >> be picking that. >> >> Using "-C -1" to put a single stripe on each OST wouldn't have any benefit >> over "-c -1". IMHO, it would probably be more useful to have negative >> values represent number of stripes per OST. 🙂 >> >> -Nathan >> From: lustre-discuss <[email protected]> on behalf of >> John Bauer <[email protected]> >> Sent: Friday, May 17, 2024 8:48 AM >> To: lustre-discuss <[email protected]> >> Subject: [lustre-discuss] Unexpected result with overstriping >> >> External email: Use caution opening links or attachments >> >> Good morning all, >> >> I am playing around with overstriping a bit and I found a behavior that, to >> me, would seem unexpected. The documentation for -C -1 indicates that the >> file should be striped over all available OSTs. The pool, which happens to >> be the default, is ssd-pool which has 32 OSTs. I got a stripeCount of 2000. >> Is this as expected? >> >> pfe20.jbauer2 213> rm -f /nobackup/jbauer2/ddd.dat >> pfe20.jbauer2 214> lfs setstripe -C -1 /nobackup/jbauer2/ddd.dat >> pfe20.jbauer2 215> lfs getstripe /nobackup/jbauer2/ddd.dat >> /nobackup/jbauer2/ddd.dat >> lmm_stripe_count: 2000 >> lmm_stripe_size: 1048576 >> lmm_pattern: raid0,overstriped >> lmm_layout_gen: 0 >> lmm_stripe_offset: 119 >> lmm_pool: ssd-pool >> obdidx objid objid group >> 119 52386287 0x31f59ef 0 >> 123 52347947 0x31ec42b 0 >> 127 52734487 0x324aa17 0 >> 121 52839396 0x32643e4 0 >> 131 52742709 0x324ca35 0 >> 116 52242659 0x31d28e3 0 >> 117 51831125 0x316e155 0 >> 124 52425218 0x31ff202 0 >> 125 52402722 0x31f9a22 0 >> 106 52700581 0x32425a5 0 >> >> edited for brevity >> >> >> _______________________________________________ >> lustre-discuss mailing list >> [email protected] >> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
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