Sequential ZFS Mirrors
By Igor Geier on Jul 21, 2008
Last month, an ambassador colleague shared the idea of having ZFS mirrors on only one hard drive. One of the immediate questions is: how fast is such a zpool? I did some tests on a 1.7 GHz Pentium M laptop with a 120 GB IDE drive (WDC WD1200BEVE) and 1 GB of main memory, running the OpenSolaris 2008.05 distribution. Leaving some space behind the root file system during the installation, I used the remaining three primary partitions for a zpool (“m3”) where the data was replicated twice (two mirrors).
|Test||homedir (within rpool)||m3|
|Creating a 1 GB file (with dd)||33 s, 32 MB/s||134 s, 7.8 MB/s|
|Reading the 1 GB file (with dd)||22 s, 46.7 MB/s||41 s, 25.6 MB/s|
|Compiling the wxWidgets library||9 m 18 s||9 m 41 s|