Re: {* 05.00 *}Re: Desperate with 870 QVO and ZFS
Date: Wed, 06 Apr 2022 21:59:50 UTC
Am 06.04.22 um 22:43 schrieb mike tancsa: > On 4/6/2022 4:18 PM, Bob Friesenhahn wrote: >> On Wed, 6 Apr 2022, egoitz@ramattack.net wrote: >>>> >>>> WE DON'T USE COMPRESSION AS IT'S NOT SET BY DEFAULT. SOME PEOPLE SAY YOU >>>> SHOULD HAVE IT ENABLED.... BUT.... JUST FOR AVOID HAVING SOME DATA >>>> COMPRESSED SOME OTHER NOT (IN CASE YOU ENABLE AND LATER DISABLE) AND >>>> FINALLY FOR AVOID ACCESSING TO INFORMATION WITH DIFFERENT CPU COSTS OF >>>> HANDLING... WE HAVE NOT TOUCHED COMPRESSION.... >> >> There seems to be a problem with your caps-lock key. >> >> Since it seems that you said that you are using maildir for your mail server, >> it is likely very useful if you do enable even rather mild compression (e.g. >> lz4) since this will reduce the write work-load and even short files will be >> stored more efficiently. >> > FYI, a couple of our big zfs mailspools sees a 1.24x and 1.23x compress ratio > with lz4. We use Maildir format as well. They are not RELENG_13 so not sure > how zstd would fair. I have got much better compression at same or less load by use of zstd-2 compared to lz4. Perhaps not typical, since this is a dovecot mdbox formatted mail pool holding mostly plain text messages without large attachments: $ df /var/mdbox Filesystem 1K-blocks Used Avail Capacity Mounted on system/var/mdbox 7234048944 9170888 7224878056 0% /var/mdbox $ zfs get compression,compressratio,used,logicalused system/var/mdbox NAME PROPERTY VALUE SOURCE system/var/mdbox compression zstd-2 inherited from system/var system/var/mdbox compressratio 2.29x - system/var/mdbox used 8.76G - system/var/mdbox logicalused 20.0G - Regards, STefan