Comments on: ZFS: Fun with ZFS – is compression and deduplication useful for my data and how much memory do I need for zfs dedup?

By: Andreas Schmidt

Andreas Schmidt — Mon, 28 Mar 2016 19:00:00 +0000

In reply to Scott S.. Thanks Scott, good point with the block size I will run some tests on that one. Which ZFS version will be the one with the better full space handling, as I just a few days ago had still issues with latest ZFSonLinux version.

By: Scott S.

Scott S. — Fri, 25 Mar 2016 17:01:00 +0000

“Please note: running ZFS over 80% of allocation (used) will make the
file-system extremely sluggish. Performance will drop down to a few
MB/sec.” – This should not be true, significant improvements were made in ZFS as it approaches closer to full space used.

Using smaller recordsize will increase the probability that a block will be deduplicated, two blocks of 64k for example is more likely than two separate 1M blocks being identical. Usually compression can only help, lz4 is so lightweight I can’t see why not to use it.

By: Andreas Schmidt

Andreas Schmidt — Mon, 02 Nov 2015 12:11:00 +0000

In reply to AngieK. It means the ratio is 1 to 1.02. So about 2% reduction from the original size. but that's an assumption, I wasn't able to find any man file explaining that ratio.

By: AngieK

AngieK — Mon, 02 Nov 2015 09:17:00 +0000

Hey so what does the x1.02 mean? What rate is that