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Tag Archives: ZIL

Crucial m550 128GB as ZIL/SLOG (the ZIL really does limit your performance)


I got my hands on an m550 128GB drive (for around $75 with the recent pre-Thanksgiving/pre-Christmas discounts). Here are some comparisons between my old ZIL (the m500 128GB) and the new one: ZIL Throughput (sustained) MB/s none 195.6 m500 128GB 124.0 m550 128GB 265.9 Here are some snippets of zpool isotat output: No ZIL


Crucial m500 120GB as a ZFS slog


I re-did my benchmarks of my ZFS ZIL using a Crucial m500. The main reason I got this drive is that it has power-loss protection. And, it’s speeds are adequate to keep up with my gigabit Ethernet samba server. Here are the results. My first run was decent, but not stellar:

I didn’t do […]

SLOG tests on a 32GB Kingston SSD with iozone


This is a follow-up on my previous post. I ran iozone both with and without the [ccie]-e[/ccie] flag. This flag includes a sync/flush in the speed calculations. This flush should tell ZFS to commit the in-process data to disk, thus flushing it to the SLOG device (or to the on-disk ZIL). I ran 4 tests: […]

ZFS slog (ZIL) considerations


Running List of Alternatives 2015-08-11 It looks from this Anandtech article that the m550 does not have as strong power-loss protection as I originally thought. It protects the “lower pages” (least-significant bits) from corruption between page writes. But, it does not protect the DRAM buffer from losing data. 2014-07-07 The Transcend MTS600 line is capable […]

Bonnie++ benchmarks on ZFS


Summary Version 1.96 Sequential Output Sequential Input Random Seeks Sequential Create Random Create Size Per Char Block Rewrite Per Char Block Num Files Create Read Delete Create Read Delete K/sec % CPU K/sec % CPU K/sec % CPU K/sec % CPU K/sec % CPU /sec % CPU /sec % CPU /sec % CPU /sec % […]