This is like your mother telling not to cross the road when you were 4 years of age but not telling you it was because you could be flattened by a car :) Can you expand on your answer? If you are in a DC with AB power, redundant UPS, dual feed from the electric company, onsite generators, dual PSU servers, is it still a bad idea? On Fri, Nov 18, 2016 at 6:52 PM, Samuel Just <sjust@xxxxxxxxxx> wrote: > Never *ever* use nobarrier with ceph under *any* circumstances. I > cannot stress this enough. > -Sam > > On Fri, Nov 18, 2016 at 10:39 AM, Craig Chi <craigchi@xxxxxxxxxxxx> wrote: >> Hi Nick and other Cephers, >> >> Thanks for your reply. >> >>> 2) Config Errors >>> This can be an easy one to say you are safe from. But I would say most >>> outages and data loss incidents I have seen on the mailing >>> lists have been due to poor hardware choice or configuring options such as >>> size=2, min_size=1 or enabling stuff like nobarriers. >> >> I am wondering the pros and cons of the nobarrier option used by Ceph. >> >> It is well known that nobarrier is dangerous when power outage happens, but >> if we already have replicas in different racks or PDUs, will Ceph reduce the >> risk of data lost with this option? >> >> I have seen many performance tuning articles providing nobarrier option in >> xfs, but there are not many of then mention the trade-off of nobarrier. >> >> Is it really unacceptable to use nobarrier in production environment? I will >> be much grateful if you guys are willing to share any experiences about >> nobarrier and xfs. >> >> Sincerely, >> Craig Chi (Product Developer) >> Synology Inc. Taipei, Taiwan. Ext. 361 >> >> On 2016-11-17 05:04, Nick Fisk <nick@xxxxxxxxxx> wrote: >> >>> -----Original Message----- >>> From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of >>> Pedro Benites >>> Sent: 16 November 2016 17:51 >>> To: ceph-users@xxxxxxxxxxxxxx >>> Subject: how possible is that ceph cluster crash >>> >>> Hi, >>> >>> I have a ceph cluster with 50 TB, with 15 osds, it is working fine for one >>> year and I would like to grow it and migrate all my old >> storage, >>> about 100 TB to ceph, but I have a doubt. How possible is that the cluster >>> fail and everything went very bad? >> >> Everything is possible, I think there are 3 main risks >> >> 1) Hardware failure >> I would say Ceph is probably one of the safest options in regards to >> hardware failures, certainly if you start using 4TB+ disks. >> >> 2) Config Errors >> This can be an easy one to say you are safe from. But I would say most >> outages and data loss incidents I have seen on the mailing >> lists have been due to poor hardware choice or configuring options such as >> size=2, min_size=1 or enabling stuff like nobarriers. >> >> 3) Ceph Bugs >> Probably the rarest, but potentially the most scary as you have less >> control. They do happen and it's something to be aware of >> >> How reliable is ceph? >>> What is the risk about lose my data.? is necessary backup my data? >> >> Yes, always backup your data, no matter solution you use. Just like RAID != >> Backup, neither does ceph. >> >>> >>> Regards. >>> Pedro. >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users@xxxxxxxxxxxxxx >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> >> _______________________________________________ >> ceph-users mailing list >> ceph-users@xxxxxxxxxxxxxx >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> >> >> >> >> Sent from Synology MailPlus >> _______________________________________________ >> ceph-users mailing list >> ceph-users@xxxxxxxxxxxxxx >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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