mdadm mirrored RAID1 performance using RAID10 -f2 (Far Layout) is the solution

The only way I've found in mdadm to make 2 drives perform like a proper RAID 1 (eg. the read speed should be 2x that of a single drive) is to use the --layout=f2 (far 2).

 

mdadm raid10 performance issues.
Be very aware that mdadm seems to default to layout=n2 (which means near). In this scenario it means it is like mdadm RAID 1 performance (you get maximum read speeds of a single drive).

dd if=/dev/md126 of=/dev/null bs=1M count=2000
2000+0 records in
2000+0 records out
2097152000 bytes (2.1 GB) copied, 6.46397 s,
180 MB/s

Now look at the difference in the same drives in layout=f2 (which means far).

dd if=/dev/md126 of=/dev/null bs=1M count=2000
2000+0 records in
2000+0 records out
2097152000 bytes (2.1 GB) copied, 6.46397 s,
324 MB/s

As we can see the speed is nearly double (a small amount of bandwidth appears to be lost as overhead due to mdadm)

 


Tags:

mdadm, mirrored, raid, layout, solutionthe, ve, eg, default, maximum, speeds, dd, dev, md, null, bs, bytes, gb, copied, mb, bandwidth, overhead,

Latest Articles

  • QEMU-KVM soundhw deprecated how to enable sound in QEMU 4.x series
  • Virtualbox Error Cannot register the hard disk because a hard disk with UUID already exists solution
  • kernel: [549267.368859] mate-terminal[7871]: segfault at 2000000101 ip 00007f5d0a9548f0 sp 00007fff7012c610 error 4 in libgobject-2.0.so.0.4800.2[7f5d0a920000+52000]
  • apcupsd how to setup and monitor APC UPS units
  • How To Password Reset, Recover, Bypass, Remove and Unlock on Windows 10,8,7,Vista,XP,NT,2000,2003,2008,2012,2016,2019 Administrative Login Programs
  • Nvidia Ubuntu Linux Screentearing Video with solution driver
  • ?? Question Marks for time, permissions and size of a file?
  • mdadm how to stop a check
  • access denied by acl file qemu-kvm: bridge helper failed
  • Linux NIC connecting at 100M instead of 1000M gigabit speeds? It could be overheating
  • "This kernel requires the following features not present on the CPU: cmov Unable to boot - please use a kernel appropriate for your CPU.
  • http://vault.centos.org/5.9/os/i386/repodata/filelists.xml.gz: [Errno -1] Metadata file does not match checksum solution
  • Linux Ubuntu Wifi Disabled Only Works When Laptop Plugged Into Wall AC Power
  • CentOS 6 impossible to compile a newer libguestfs
  • chroot
  • How To Get Started on Ubuntu with gpt-2 OpenAI Text Prediction
  • Remove cloud-init in your VM
  • QEMU-KVM KVM Command Line Practical Guide
  • Linux How To Change NIC Name to eth0 instead of enps33 or enp0s25
  • virt-resize: error: libguestfs error: could not create appliance through libvirt.