It depends on size of the data that you are storing and the block size. Here is a good primer on it: http://constantin.glez.de/blog/2011/07/zfs-dedupe-or-not-dedupe As a quick estimate, about 5GB per 1TB or storage for SSD. However I believe that you would need even more RAM since only a 1/4 of the RAM will be used for the dedupe table with ZFS. Thank you, Ryan Palamara ZAIS Group, LLC 2 Bridge Avenue, Suite 322 Red Bank, New Jersey 07701 Phone: (732) 450-7444 Ryan.palamara at zaisgroup.com -----Original Message----- From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On Behalf Of Les Mikesell Sent: Thursday, September 13, 2012 3:09 PM To: CentOS mailing list Subject: Re: [CentOS] Deduplication data for CentOS? On Thu, Sep 13, 2012 at 12:06 PM, Ryan Palamara <Ryan.Palamara at zaisgroup.com> wrote: > The better option for ZFS would be to get a SSD and move the dedupe table onto that drive instead of having it in RAM, because it can become massive. What's 'massive' in dollars these days? -- Les Mikesell lesmikesell at gmail.com _______________________________________________ CentOS mailing list CentOS at centos.org http://lists.centos.org/mailman/listinfo/centos ________________________________ This e-mail message is intended only for the named recipient(s) above. It may contain confidential information. If you are not the intended recipient you are hereby notified that any dissemination, distribution or copying of this e-mail and any attachment(s) is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender by replying to this e-mail and delete the message and any attachment(s) from your system. Thank you. This is not an offer (or solicitation of an offer) to buy/sell the securities/instruments mentioned or an official confirmation. This is not research and is not from ZAIS Group but it may refer to a research analyst/research report. Unless indicated, these views are the author's and may differ from those of ZAIS Group research or others in the Firm. We do not represent this is accurate or complete and we may not update this. Past performance is not indicative of future returns. IRS CIRCULAR 230 NOTICE:. To comply with requirements imposed by the IRS, we inform you that any U.S. federal tax advice contained herein (including any attachments), unless specifically stated otherwise, is not intended or written to be used, and cannot be used, for the purpose of (i) avoiding penalties under the Internal Revenue Code or (ii) promoting, marketing or recommending any transaction or matter addressed herein to another party. Each taxpayer should seek advice based on the taxpayer's particular circumstances from an independent tax advisor. "ZAIS", "ZAIS Group" and "ZAIS Solutions" are trademarks of ZAIS Group, LLC.