<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Could someone please help out with this? This memory consumption is preventing me from working with the device mapper…<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>I created a mapped device with a table consisting 10, 20 and 30 mirror targets to examine the memory consumption.<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>You can see that the memory consumption is very high (in terms of mega).<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>I also verified that CONFIG_BLK_DEV_INTEGRITY is disabled.<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Do you have any idea why does a mirror target consumes so much memory?<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>For 10 mirror targets the memory consumption is ~7M:<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>==========================================<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# free –m<o:p></o:p></p><p class=MsoNormal style='margin-left:72.0pt;text-align:left;text-indent:36.0pt;direction:ltr;unicode-bidi:embed'>total used free shared buffers cached<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Mem: 7837 566 7271 0 105 372<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>-/+ buffers/cache: 88 7749<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Swap: 0 0 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# dmsetup create mirror_dev /tmp/mirror_core_sync_10.txt<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# free -m<o:p></o:p></p><p class=MsoNormal style='margin-left:72.0pt;text-align:left;text-indent:36.0pt;direction:ltr;unicode-bidi:embed'>total used free shared buffers cached<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Mem: 7837 573 7264 0 105 372<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>-/+ buffers/cache: 95 7742<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Swap: 0 0 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>For 20 mirror targets the memory consumption is ~12M:<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>===========================================<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# dmsetup remove mirror_dev<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# free –m<o:p></o:p></p><p class=MsoNormal style='margin-left:72.0pt;text-align:left;text-indent:36.0pt;direction:ltr;unicode-bidi:embed'>total used free shared buffers cached<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Mem: 7837 566 7271 0 105 372<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>-/+ buffers/cache: 89 7749<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Swap: 0 0 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# dmsetup create mirror_dev /tmp/mirror_core_sync_20.txt<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# free –m<o:p></o:p></p><p class=MsoNormal style='margin-left:72.0pt;text-align:left;text-indent:36.0pt;direction:ltr;unicode-bidi:embed'>total used free shared buffers cached<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Mem: 7837 580 7257 0 106 372<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>-/+ buffers/cache: 101 7736<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Swap: 0 0 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>For 30 mirror targets the memory consumption is ~19M:<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>===========================================<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# dmsetup remove mirror_dev<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# free –m<o:p></o:p></p><p class=MsoNormal style='margin-left:72.0pt;text-align:left;text-indent:36.0pt;direction:ltr;unicode-bidi:embed'>total used free shared buffers cached<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Mem: 7837 568 7269 0 106 372<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>-/+ buffers/cache: 89 7748<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Swap: 0 0 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# dmsetup create mirror_dev /tmp/mirror_core_sync_30.txt<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# free –m<o:p></o:p></p><p class=MsoNormal style='margin-left:72.0pt;text-align:left;text-indent:36.0pt;direction:ltr;unicode-bidi:embed'>total used free shared buffers cached<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Mem: 7837 587 7250 0 106 372<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>-/+ buffers/cache: 108 7729<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>Swap: 0 0 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'><o:p> </o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>This is how the mapped file table looks like (you get the picture for the other 20 and 30 target files):<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>============================================================================<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>[root@vpc09 ~]# cat /tmp/mirror_core_sync_10.txt<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>0 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>8 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>16 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>24 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>32 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>40 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>48 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>56 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>64 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p><p class=MsoNormal style='text-align:left;direction:ltr;unicode-bidi:embed'>72 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0<o:p></o:p></p></div></body></html>