Setting up software RAID on Debian with mdadm

Software RAID has come a long way. Unless you have some very high-rate, high-volume, I/O workloads with SLAs that will otherwise cost you money, for the most part a software RAID will perform just fine. One of the primary benefits of using software RAID is the portability of your disks/data. If a box on which you have a software RAID dies somehow and at least some (depending on your RAID configuration) of drives survive, you can easily resurrect the RAID → Continue reading “Setting up software RAID on Debian with mdadm”

Adding a New Disk to a Linux Server and Creating an LVM Partition

There are a number of tutorials online for adding a new disk to a machine and then extending an existing LVM partition to use the new device.

This particular tutorial covers the use case of adding a new disk to a Linux server and then creating a NEW LVM partition on it without modifying the existing devices and LVM partitions.

The first thing you will need to do is add the physical device to the server (or VM).

Then, you → Continue reading “Adding a New Disk to a Linux Server and Creating an LVM Partition”

How To Benchmark Disk I/O

Here is a quick snipped on how to benchmark Disk I/O with dd.

time sh -c "dd if=/dev/zero of=/home/rchapin/test.zeros bs=1024k count=10000 && sync"

10000+0 records in
10000+0 records out
10485760000 bytes (10 GB) copied, 81.4124 s, 129 MB/s

real    1m21.950s
user    0m0.810s
sys     0m5.474s

Will do a write test of 10GB.

You can do a similar test and read from that file generated and write to another file or /dev/null to get an idea of the read speeds.

See the → Continue reading “How To Benchmark Disk I/O”