saikee
Explorer
- Joined
- Feb 7, 2017
- Messages
- 77
I have two zpools of identical size of 5x8TB in RAIDZ1. One is a source data of 15.23Tib (54% filled) and the other has been emptied to receive data as a backup. FreeNAS version is 11.2-U5 with the new web interface. Both pools are normal and not encrypted.
For fastest speed I had both pools placed inside my FreeNAS server and mounted both pools in /mnt/source and /mnt/target respectively. The files are mainly large videos. The file transfers involved only the internal Sata controllers and so no traffic in the network card.
For checking the progress of the copying action of a directory1 I used the command
For “each” of the 5 disks I got an “average” read and write speeds of 2.45Mb/s from the source pool and 26Mb/s on the target pool respectively. The average speeds were nearly the same in the 5 disks of each pool.
I was puzzled by FreeNAS’s apparent ability to read one data from a source pool but to write 10 times more (or faster) on a target pool.
Thinking I might be able to speed up the process a little bit I opened up a second web front to the same FreeNAS server and copied the next directory2 while directory1 was still being copied over.
To my surprise the overall average read and write speed changed to 6.8Mb/s and 2.5Mb/s when both directories were being copied over.
The 15.23Tib data took about 17 hours to copied over. The back up copy appears sound and healthy.
My question : Is this normal for FreeNAS to read one data and write 10 times more and then later read one data and write only 1/3 of it? Or the Version 11.2-U5 has a bug in the display?
Since both zpools are identical in geometry (hard disk size, type, number and RAID are the same) should we not expect the average reading speed to match the write speed?
For fastest speed I had both pools placed inside my FreeNAS server and mounted both pools in /mnt/source and /mnt/target respectively. The files are mainly large videos. The file transfers involved only the internal Sata controllers and so no traffic in the network card.
For checking the progress of the copying action of a directory1 I used the command
Code:
cp -R mnt/source/directory1/ mnt/target/directory1/
For “each” of the 5 disks I got an “average” read and write speeds of 2.45Mb/s from the source pool and 26Mb/s on the target pool respectively. The average speeds were nearly the same in the 5 disks of each pool.
I was puzzled by FreeNAS’s apparent ability to read one data from a source pool but to write 10 times more (or faster) on a target pool.
Thinking I might be able to speed up the process a little bit I opened up a second web front to the same FreeNAS server and copied the next directory2 while directory1 was still being copied over.
Code:
cp -R mnt/source/directory2/ mnt/target/directory2/
To my surprise the overall average read and write speed changed to 6.8Mb/s and 2.5Mb/s when both directories were being copied over.
The 15.23Tib data took about 17 hours to copied over. The back up copy appears sound and healthy.
My question : Is this normal for FreeNAS to read one data and write 10 times more and then later read one data and write only 1/3 of it? Or the Version 11.2-U5 has a bug in the display?
Since both zpools are identical in geometry (hard disk size, type, number and RAID are the same) should we not expect the average reading speed to match the write speed?