<div>Hi,</div><div><br></div><div>I have been testing some LSI 9260 RAID cards for use with Lustre v1.8.6 but have found that the "megaraid_sas" driver is not really able to facilitate the 1MB full stripe IOs that Lustre likes. This topic has also come up recently in the following two email threads:</div>
<div><br></div><a href="http://groups.google.com/group/lustre-discuss-list/browse_thread/thread/65a1fdc312b0eccb#" target="_blank">http://groups.google.com/group/lustre-discuss-list/browse_thread/thread/65a1fdc312b0eccb#</a>
<div><a href="http://groups.google.com/group/lustre-discuss-list/browse_thread/thread/fcf39d85b7e945ab" target="_blank">http://groups.google.com/group/lustre-discuss-list/browse_thread/thread/fcf39d85b7e945ab</a></div><div>
<br></div><div>I was able to up themax_hw_sectors_kb -> 1024 by setting the "max_sectors" megaraid_sas module option but found that the IOs were still being pretty fragmented:</div><div><br></div><div><div>
disk I/O size ios % cum % | ios % cum %</div><div>4K: 3060 0 0 | 2611 0 0</div><div>8K: 3261 0 0 | 2664 0 0</div><div>16K: 6408 0 1 | 5296 0 1</div>
<div>32K: 13025 1 2 | 10692 1 2</div><div>64K: 48397 4 6 | 26417 2 4</div><div>128K: 50166 4 10 | 42218 4 9</div><div>256K: 113124 9 20 | 86516 8 17</div>
<div>512K: 677242 57 78 | 448231 45 63</div><div>1M: 254195 21 100 | 355804 36 100</div></div><div><br></div><div>So next I looked at the sg_tablesize and found it was being set to "80" by the driver (which queries the firmware). I tried to hack the driver and increase this value but bad things happened and so it looks like it is a genuine hardware limit with these cards.</div>
<div><br></div><div>The overall throughput isn't exactly terrible because the RAIDwrite-backcache does a reasonable job but I suspect it could be better, e.g.</div><div><br></div><div><div>ost 3 sz 201326592K rsz 1024K obj 192 thr 192 write 1100.52 [ 231.75, 529.96] read 940.26 [ 275.70, 357.60]</div>
<div>ost 3 sz 201326592K rsz 1024K obj 192 thr 384 write 1112.19 [ 184.80, 546.43] read 1169.20 [ 337.63, 462.52]</div><div>ost 3 sz 201326592K rsz 1024K obj 192 thr 768 write 1217.79 [ 219.77, 665.32] read 1532.47 [ 403.58, 552.43]</div>
<div>ost 3 sz 201326592K rsz 1024K obj 384 thr 384 write 920.87 [ 171.82, 466.77] read 901.03 [ 257.73, 372.87]</div><div>ost 3 sz 201326592K rsz 1024K obj 384 thr 768 write 1058.11 [ 166.83, 681.25] read 1309.63 [ 346.64, 484.51]</div>
</div><div><br></div><div>All of this brings me to my main question - what internal cards have people here used which work well with Lustre? 3ware, Areca or other models of LSI?</div>
<div><br></div><div>Cheers,</div><div><br></div><div>Daire</div>