Re: uint32_t BlueStore::Extent::logical_offset?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 22 Nov 2016, Matt Benjamin wrote:
> It would seem preferable not to bake-in such a limit on extent size, 
> even if offsets exceeding that won't immediately be used.

All things being equal, sure.  But 4gb is 1-2 orders of magnitude larger 
than we recommend or design for, and it costs us memory.

FWIW, the logical_offset is varint encoded on disk, so the disk format is 
actually unsized.

In the meantime, I think that 100GB object size limit should really be 
more like 100MB!

sage


> 
> Matt
> 
> ----- Original Message -----
> > From: "Somnath Roy" <Somnath.Roy@xxxxxxxxxxx>
> > To: "Sage Weil" <sage@xxxxxxxxxxxx>, "Igor Fedotov" <ifedotov@xxxxxxxxxxxx>
> > Cc: "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>
> > Sent: Tuesday, November 22, 2016 4:53:18 PM
> > Subject: RE: uint32_t BlueStore::Extent::logical_offset?
> > 
> > Sage,
> > OSD max obect size in the latest master is 100G , it used to be smaller..
> > 
> > OPTION(osd_max_object_size, OPT_U64, 100*1024L*1024L*1024L) // OSD's maximum
> > object size
> > 
> > Thanks & Regards
> > Somnath
> > 
> > -----Original Message-----
> > From: ceph-devel-owner@xxxxxxxxxxxxxxx
> > [mailto:ceph-devel-owner@xxxxxxxxxxxxxxx] On Behalf Of Sage Weil
> > Sent: Tuesday, November 22, 2016 1:47 PM
> > To: Igor Fedotov
> > Cc: ceph-devel
> > Subject: Re: uint32_t BlueStore::Extent::logical_offset?
> > 
> > On Tue, 22 Nov 2016, Igor Fedotov wrote:
> > > Hi Sage,
> > >
> > >
> > > I'm wondering why BlueStore::Extent::logical_offset is 32-bit wide.
> > >
> > > IMHO it's to be uint64_t unless we limit onode size to 4Gb.
> > >
> > > Looks like we have implicit truncate when doing set_lextent/new Extent
> > > at the moment and hence some issues with large onodes are possible.
> > 
> > The max object size enforced in the OSD is ~128 MB (or in that neighborhood,
> > if I remember correctly).  We really shouldn't be storing individual rados
> > objects that are orders of magnitude larger than that.
> > 
> > sage
> > --
> > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the
> > body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at
> > http://vger.kernel.org/majordomo-info.html
> > PLEASE NOTE: The information contained in this electronic mail message is
> > intended only for the use of the designated recipient(s) named above. If the
> > reader of this message is not the intended recipient, you are hereby
> > notified that you have received this message in error and that any review,
> > dissemination, distribution, or copying of this message is strictly
> > prohibited. If you have received this communication in error, please notify
> > the sender by telephone or e-mail (as shown above) immediately and destroy
> > any and all copies of this message in your possession (whether hard copies
> > or electronically stored copies).
> > --
> > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
> 
> -- 
> Matt Benjamin
> Red Hat, Inc.
> 315 West Huron Street, Suite 140A
> Ann Arbor, Michigan 48103
> 
> http://www.redhat.com/en/technologies/storage
> 
> tel.  734-821-5101
> fax.  734-769-8938
> cel.  734-216-5309
> 
> 
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [CEPH Users]     [Ceph Large]     [Information on CEPH]     [Linux BTRFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux