Hi ! As, probably, many of us I am playing with snv_90 and ZFS root. During the installation I didn't see any possibility to set the properties of the datasets. In particular compression. I see that default installation leaves the compression property untouched for all the created datasets, with rpool/dump being the only exception. For it the compression property is explicitly set to "off".
venus:/home/imp> zfs get compression NAME PROPERTY VALUE SOURCE rpool compression off default rpool/ROOT compression off default rpool/ROOT/snv_90 compression off default rpool/dump compression off local rpool/export compression off default rpool/export/home compression off default rpool/snv_90_gzip compression gzip local rpool/snv_90_lzjb compression lzjb local rpool/swap compression off default I checked what would be the disk saving if compression would be turned on and here are the results for the nearly full SXCE install. rpool/snv_90_gzip and rpool/snv_90_lzjb are copies of the rpool/ROOT/snv_90 ith respective compression turned on. venus:/home/imp> zfs list | grep snv_90 rpool/ROOT/snv_90 4.79G 136G 4.79G / rpool/snv_90_gzip 1.82G 136G 1.82G /rpool/snv_90_gzip rpool/snv_90_lzjb 2.80G 136G 2.80G /rpool/snv_90_lzjb venus:/home/imp> zfs get compressratio | grep snv_90 rpool/ROOT/snv_90 compressratio 1.00x - rpool/snv_90_gzip compressratio 2.63x - rpool/snv_90_lzjb compressratio 1.70x - venus:/home/imp> With lzjb the compression ratio is significant and with gzip is even more so. I believe that having compression enabled on root file system can be a good thing. System files are usually read-only, so the CPU penalty on write for higher compression should be negligible. And decompression on read supposed to be pretty fast. So the questions are: 1. Are there any reasons to *not* enable compression by default ? 2. How can I do it ? (I think I can run "zfs set compression=on rpool/ROOT/snv_90" in the other window, right after the installation begins, but I would like less hacky way.) -- Regards, Cyril _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
