Seeing as you want to be able to lose 2 hosts and still have a writeable cluster your minimum m is at least 3 (k+1 is required for a writeable cluster usually). Your failure domain will have to be set to host and your k+m can't be larger than your failure domain (so no number larger than 15 or ideally smaller than that so the cluster could rebalance in event of hard failure). I'm not entirely sure what the performance impact is of creating an overly large stripe, you'll have to test that out. ________________________________ From: Christophe BAILLON <cb@xxxxxxx> Sent: 07 September 2022 15:25 To: ceph-users <ceph-users@xxxxxxx> Subject: Advice to create a EC pool with 75% raw capacity usable CAUTION: This email originates from outside THG Hello, I need advice on the creation of an EC profile and the associate crush rule, for a cluster of 15 nodes, each with 12 x 18Tb disks with the objective of being able to lose 2 hosts or 4 disks. I would like to have the most space available, a 75% ratio would be ideal If you can give me some examples ou some good links, it will be nice Regards _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx Danny Webb Principal OpenStack Engineer The Hut Group<http://www.thehutgroup.com/> Tel: Email: Danny.Webb@xxxxxxxxxxxxxxx<mailto:Danny.Webb@xxxxxxxxxxxxxxx> For the purposes of this email, the "company" means The Hut Group Limited, a company registered in England and Wales (company number 6539496) whose registered office is at Fifth Floor, Voyager House, Chicago Avenue, Manchester Airport, M90 3DQ and/or any of its respective subsidiaries. Confidentiality Notice This e-mail is confidential and intended for the use of the named recipient only. If you are not the intended recipient please notify us by telephone immediately on +44(0)1606 811888 or return it to us by e-mail. Please then delete it from your system and note that any use, dissemination, forwarding, printing or copying is strictly prohibited. Any views or opinions are solely those of the author and do not necessarily represent those of the company. Encryptions and Viruses Please note that this e-mail and any attachments have not been encrypted. They may therefore be liable to be compromised. Please also note that it is your responsibility to scan this e-mail and any attachments for viruses. We do not, to the extent permitted by law, accept any liability (whether in contract, negligence or otherwise) for any virus infection and/or external compromise of security and/or confidentiality in relation to transmissions sent by e-mail. Monitoring Activity and use of the company's systems is monitored to secure its effective use and operation and for other lawful business purposes. Communications using these systems will also be monitored and may be recorded to secure effective use and operation and for other lawful business purposes. hgvyjuv _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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