Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

>> Would it be 4 objects of 24M and 4 objects of 250KB? Or will the last 4 objects be artificially padded (with 0's) to meet the stripe_unit? It will be 4 object of 24M + 1M stored on the 5th object If you write 104M : 4 object of 24M + 8M stored on the 5th object If you write 105M : 4 obje

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Maybe an additional example where the numbers don't line up all so nicely would be good as well. For example it's not immediately obvious to me what would happen with the stripe settings given by your example but you write 97M of data Would it be 4 objects of 24M and 4 objects of 250KB? Or will the

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

That looks right to me... PRs for the Ceph docs are welcome! :) On Mon, Oct 16, 2017 at 4:35 PM Alexander Kushnirenko wrote: > Hi, Gregory, Ian! > > There is very little information on striper mode in Ceph documentation. > Could this explanation help? > > The logic of striper mode is very much t

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Hi, Gregory, Ian! There is very little information on striper mode in Ceph documentation. Could this explanation help? The logic of striper mode is very much the same as in RAID-0. There are 3 parameters that drives it: stripe_unit - the stripe size (default=4M) stripe_count - how many objects

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Oh! I put a wrong link, sorry The picture which explains stripe_unit and stripe count is here: https://indico.cern.ch/event/330212/contributions/1718786/attachments/642384/883834/CephPluginForXroot.pdf I tried to attach it in the mail, but it was blocked. On Wed, Oct 11, 2017 at 3:16 PM, Alex

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Hi, Ian! Thank you for your reference! Could you comment on the following rule: object_size = stripe_unit * stripe_count Or it is not necessarily so? I refer to page 8 in this report: https://indico.cern.ch/event/531810/contributions/2298934/at tachments/1358128/2053937/Ceph-Experience-at-RAL-f

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Hi, Gregory! You are absolutely right! Thanks! The following sequence solves the problem: rados_striper_set_object_layout_stripe_unit(m_striper, stripe_unit); rados_striper_set_object_layout_stripe_count(m_striper, stripe_count); int stripe_size = stripe_unit * stripe_count; rados_striper_set_obj

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Hi Gregory You're right, when setting the object layout in libradosstriper, one should set all three parameters (the number of stripes, the size of the stripe unit, and the size of the striped object). The Ceph plugin for GridFTP has an example of this at https://github.com/stfc/gridFTPCephPlug

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Well, just from a quick skim, libradosstriper.h has a function rados_striper_set_object_layout_object_size(rados_striper_t striper, unsigned int object_size) and libradosstriper.hpp has one in RadosStriper set_object_layout_object_size(unsigned int object_size); So I imagine you specify it

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Hi, Gregory! It turns out that this error is internal CEPH feature. I wrote standalone program to create 132M object in striper mode. It works only for 4M stripe. If you set stripe_unit = 2M it still creates 4M stripe_unit. Anything bigger than 4M causes crash here

Re: [ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

I haven't used the striper, but it appears to make you specify sizes, stripe units, and stripe counts. I would expect you need to make sure that the size is an integer multiple of the stripe unit. And it probably defaults to a 4MB object if you don't specify one? On Fri, Sep 29, 2017 at 2:09 AM Al

[ceph-users] Bareos and libradosstriper works only for 4M sripe_unit size

Hi, I'm trying to use CEPH-12.2.0 as storage for with Bareos-16.2.4 backup with libradosstriper1 support. Libradosstriber was suggested on this list to solve the problem, that current CEPH-12 discourages users from using object with very big size (>128MB). Bareos treat Rados Object as Volume and