| # mdadm |
| Some tips and tricks regarding `mdadm`. |
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| # |
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| # |
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| ``` |
| fio --name TEST --filename=temp.file --rw=randrw --size=4g --io_size=10g --blocksize=4k --ioengine=libaio --fsync=1 --iodepth=1 --direct=1 --numjobs=16 --runtime=60 |
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| Run status group 0 (all jobs): |
| READ: bw=489KiB/s (500kB/s), 28.9KiB/s-32.5KiB/s (29.5kB/s-33.2kB/s), io=28.7MiB (30.1MB), run=60002-60062msec |
| WRITE: bw=499KiB/s (511kB/s), 29.4KiB/s-33.2KiB/s (30.1kB/s-33.0kB/s), io=29.3MiB (30.7MB), run=60002-60062msec |
| ``` |
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| # |
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| ``` |
| fio --name TEST --filename=temp.file --rw=randrw --size=4g --io_size=10g --blocksize=128k --ioengine=libaio --fsync=1 --iodepth=1 --direct=1 --numjobs=16 --runtime=60 |
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| Run status group 0 (all jobs): |
| READ: bw=16.5MiB/s (17.2MB/s), 1007KiB/s-1107KiB/s (1031kB/s-1133kB/s), io=988MiB (1036MB), run=60003-60043msec |
| WRITE: bw=16.7MiB/s (17.6MB/s), 1017KiB/s-1126KiB/s (1042kB/s-1153kB/s), io=1005MiB (1054MB), run=60003-60043msec |
| ``` |
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| # |
| |
| ``` |
| fio --name TEST --filename=temp.file --rw=randrw --size=4g --io_size=10g --blocksize=4M --ioengine=libaio --fsync=1 --iodepth=1 --direct=1 --numjobs=16 --runtime=60 |
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| Run status group 0 (all jobs): |
| READ: bw=208MiB/s (218MB/s), 11.9MiB/s-14.1MiB/s (12.5MB/s-14.7MB/s), io=12.2GiB (13.1GB), run=60011-60081msec |
| WRITE: bw=205MiB/s (215MB/s), 11.9MiB/s-13.8MiB/s (12.4MB/s-14.5MB/s), io=12.1GiB (12.9GB), run=60011-60081msec |
| ``` |
|
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| # |
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| We have 14 free disks to be used, so let's create raid 10 array with 10 disk and 4 four as `spare` devices for auto-rebuild in case of failure |
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| ``` |
| mdadm -v --create /dev/md0 --level=raid10 --layout=f2 --raid-devices=10 /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk /dev/sdl |
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| mdadm --detail /dev/md0 |
| /dev/md0: |
| Version : 1.2 |
| Creation Time : Tue Jun 22 12:20:31 2021 |
| Raid Level : raid10 |
| Array Size : 48831523840 (45.48 TiB 50.00 TB) |
| Used Dev Size : 9766304768 (9.10 TiB 10.00 TB) |
| Raid Devices : 10 |
| Total Devices : 10 |
| Persistence : Superblock is persistent |
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| Intent Bitmap : Internal |
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| Update Time : Tue Jun 22 12:20:58 2021 |
| State : clean, resyncing |
| Active Devices : 10 |
| Working Devices : 10 |
| Failed Devices : 0 |
| Spare Devices : 0 |
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| Layout : far=2 |
| Chunk Size : 512K |
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| Consistency Policy : bitmap |
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| Resync Status : 0% complete |
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| Name : storage02.rdu2.centos.org:0 (local to host storage02.rdu2.centos.org) |
| UUID : 521a6cbb:cb76e0c1:dc7fe98c:fe1b0bec |
| Events : 5 |
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| Number Major Minor RaidDevice State |
| 0 8 32 0 active sync /dev/sdc |
| 1 8 48 1 active sync /dev/sdd |
| 2 8 64 2 active sync /dev/sde |
| 3 8 80 3 active sync /dev/sdf |
| 4 8 96 4 active sync /dev/sdg |
| 5 8 112 5 active sync /dev/sdh |
| 6 8 128 6 active sync /dev/sdi |
| 7 8 144 7 active sync /dev/sdj |
| 8 8 160 8 active sync /dev/sdk |
| 9 8 176 9 active sync /dev/sdl |
| ``` |
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| Let's increase the raid array speed |
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| ``` |
| md_device=md0 |
| echo max > /sys/block/${md_device}/md/sync_max |
| echo 500000 > /sys/block/${md_device}/md/sync_speed_min |
| echo 500000 > /proc/sys/dev/raid/speed_limit_max |
| ``` |
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| # |
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| ``` |
| for i in m n o p ; do mdadm --add /dev/md0 /dev/sd${i} ; done |
| mdadm: added /dev/sdm |
| mdadm: added /dev/sdn |
| mdadm: added /dev/sdo |
| mdadm: added /dev/sdp |
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| mdadm --detail /dev/md0|grep Devices |
| Raid Devices : 10 |
| Total Devices : 14 |
| Active Devices : 10 |
| Working Devices : 14 |
| Failed Devices : 0 |
| Spare Devices : 4 |
| ``` |
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| # |
| Let's now create a vg_array volume on top of new /dev/md0 raid10 device :-1: |
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| ``` |
| pvcreate /dev/md0 |
| vgcreate vg_array /dev/md0 |
| ``` |
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| # |
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| ``` |
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| ``` |
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