Hi Mads, Please see this article a bit old now. http://www.infostor.com/disk-arrays/skyera-raid-5-kills-ssd-arrays.html I think you should look for AFA solutions (PureStorage - our T0 storage) with inline deduplication and compression. I think that RAID 6 is a bad idea. Tomek W dniu 2015-03-03 o 14:20, Mads Nordholm pisze: > Very useful input indeed. I think I might end up going with a more > conventional setup for starters, and then play with CEPH on the site. And > that then leads to another question: Does anybody have some input on what > RAID level to use for a more conventional storage setup? I am looking at > deploying a setup that exclusively uses SSD, so I am probably a bit more > interested in getting as many usable GBs as possible, than I am in > optimising I/O. > > So far, I have been hearing people advocating RAID 10 as well as RAID 6. I > am personally leaning towards RAID 6, but I would love to get some input > from someone with more experience using these different RAID levels in > production. > > -- > Mads Nordholm > > On Tue, Mar 3, 2015 at 7:34 PM, Vadim Kimlaychuk > wrote: > >> Andrija, >> >> This is my choise already -- FreeBSD + ZFS with SSD for ZIL/L2ARC >> cache + NFS. Going to be at production within couple of weeks. You have >> read my thoughts ! :) >> >> Vadim. >> >> -----Original Message----- >> From: Andrija Panic [mailto:andrija.panic@gmail.com] >> Sent: Tuesday, March 03, 2015 2:25 PM >> To: users@cloudstack.apache.org >> Subject: Re: Hardware question >> >> I'm personaly having fights with CEPh used for Primary storage - I ike >> CEPH VERY MUCH, but hate it at the same time (hars word, I know...) >> >> For Primary storage - my suggestions, play arround if you like, but avoid >> it at the end...till it matures better, or simply the integration with CEPH >> matures better. >> >> If you are not using 10G network and serious hardware - it's crappy >> experience... SSD for Journal, etc... >> >> It's a fight - whenever I do some maintance on CEPH I end up swetting, >> clients asking why is everythgin so slow, etc... >> >> For our next cloud, I'm going with ZFS/NFS definitively... >> >> Be warned :) >> >> Cheers >> >> On 3 March 2015 at 13:15, Vadim Kimlaychuk >> wrote: >> >>> Mads, >>> >>> CEPH is good indeed, but keep in mind that you should really >>> be expert at this type of SDS. There are points that are not visible >>> from the first look and may bring some unpleasent surprises. For >> example: "default" >>> option for storage I have tested was to make snapshots automatically >>> from the files being saved to primary storage. As a consequence when >>> you delete VM there are artifacts (snapshots) that are connect to >>> deleted VM not being deleted by Cloudstack (since CS does not know they >> exist). >>> Another point - you can't directly use it as secondary >>> storage. Need to set-up application server and run RadosGW. >>> Performance - is a big question mark here. You need NFS or iSCSI anyway. >>> What we haven't fully tested - disaster recovery or >>> malfunction simulation. You must know how to recover from all types of >>> the faults. It is very easy to lose everything by just doing wrong >>> things (or in wrong order). From my point of view Ceph is rather >>> complex to start together with CS. It may be easy to set up, but not so >> easy to manage. >>> Will suggest you to run it like a year at development to make >>> yourself confident you can manage it. >>> >>> Regards, >>> >>> Vadim. >>> >>> -----Original Message----- >>> From: Mads Nordholm [mailto:mads@nordholm.dk] >>> Sent: Monday, March 02, 2015 8:16 PM >>> To: users@cloudstack.apache.org >>> Subject: Re: Hardware question >>> >>> Thanks a lot for your answer, Lucian. CEPH sounds like a very >>> interesting solution. I will have to do some more research on that. >>> >>> -- >>> Mads Nordholm >>> >>> On Tue, Mar 3, 2015 at 12:32 AM, Nux! wrote: >>> >>>> Hi Mads, >>>> >>>> Imo, if you want that flexibility you should go with non-local storage. >>>> CEPH is a popular choice here, but you will need 10 Gbps between >>>> hypervisors and storage servers if you want reasonable performance. >>>> So, if you need more storage just add more CEPH servers. Need more >>>> compute, add more hypervisors. >>>> >>>> HTH >>>> Lucian >>>> >>>> -- >>>> Sent from the Delta quadrant using Borg technology! >>>> >>>> Nux! >>>> www.nux.ro >>>> >>>> ----- Original Message ----- >>>>> From: "Mads Nordholm" >>>>> To: users@cloudstack.apache.org >>>>> Sent: Monday, 2 March, 2015 17:19:40 >>>>> Subject: Hardware question >>>>> I am planning a small Cloudstack setup (using KVM for >>>>> virtualisation) >>>> that >>>>> will allow me to run roughly 100 VPSs with these average >> requirements: >>>>> - 1 core >>>>> - 512 MB RAM >>>>> - 20 GB SSD >>>>> >>>>> I am interested in input regarding a hardware configuration that >>>>> will support this, and how to best build a small setup that will >>>>> scale easily >>>> as >>>>> I grow. Within a year or so, I expect to have more than 1,000 >>>>> guest >>>> running. >>>>> I basically need a setup that will not completely break the bank >>>>> as I >>>> start >>>>> out, but also one that will scale well as I grow. I am >>>>> particularly concerned with being able to add only the resources I >>>>> need. If I need >>>> more >>>>> storage, I want to be able to add only that (preferably just by >>>>> adding disks to a RAID array), and if I need more computing power, >>>>> I want to be able to add only that. >>>>> >>>>> Any input greatly appreciated. >>>>> >>>>> -- >>>>> Mads Nordholm >> >> >> -- >> >> Andrija Panić >>