Björn Schneider
2008-Nov-24 10:20 UTC
[Xen-users] GPLPV-drivers: size limit in "hard disk drivers" for volumes?
Hi,
I''ve encountered a strange behaviour of the block device PV driver:
with
the Qemu-derived IO-emulation I can easily access both virtual drives of
50 GByte and 2 Terabyte.
When I activate GPLPV, only the 50G system partition shows up; the 2
TByte one is completely absent.
Is there a limit the GPLPV block driver can handle? -- everything else
seems to work fine... and yes, I need that 2TByte disk. It''s a
fileserver :)
I could of course try to split the disk and use the Windows volume
management to assemble it back -- but I don''t know how to do that
exactly and it''d add another management layer. Which I don''t
want to.
Any ideas or maybe even a solution? :) But it''s not that urgent, I can
still use the IO emulation until the system gets productive, which
isn''t
before January. And maybe even still then.
Thanks,
Björn Schneider
--
==========================================================Björn Schneider, BSc.
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James Harper
2008-Nov-24 10:33 UTC
RE: [Xen-users] GPLPV-drivers: size limit in "hard disk drivers" forvolumes?
> Hi, > > I''ve encountered a strange behaviour of the block device PV driver: with > the Qemu-derived IO-emulation I can easily access both virtual drives of > 50 GByte and 2 Terabyte. > When I activate GPLPV, only the 50G system partition shows up; the 2 > TByte one is completely absent. > > Is there a limit the GPLPV block driver can handle? -- everything else > seems to work fine... and yes, I need that 2TByte disk. It''s a > fileserver :) > I could of course try to split the disk and use the Windows volume > management to assemble it back -- but I don''t know how to do that > exactly and it''d add another management layer. Which I don''t want to. > > Any ideas or maybe even a solution? :) But it''s not that urgent, I can > still use the IO emulation until the system gets productive, which isn''t > before January. And maybe even still then. >What version of the drivers are you using, and also the exact sector count of the disk? 2TByte is exactly 2^32 * 512 byte sectors, eg right on the limit of the number of sectors a 32 bit integer can hold. I''ll have to check, but I may only be using the 32 bit SCSI commands... if you are actually just under 2TB then this probably won''t be the problem. James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Björn Schneider
2008-Nov-25 14:24 UTC
Re: [Xen-users] GPLPV-drivers: size limit in "hard disk drivers" forvolumes?
Hi, I''m using the "Xen PV Drivers 0.9.12-pre4.exe" package on Windows 2008 Server SP1 32bit. The Dom0 is Ubuntu 8.04LTS amd64 with Ubuntu''s kernel 2.6.24-21-xen and Xen 3.2.1-rc1-pre. I''ve reduced the size down to a few sectors less than 1 Terabyte, and now it works (couldn''t pin it down exactly to the sector limit, as LVM2 uses ''LE units'' which contain several sectors). working size: 2147475456 sectors (1099507433472 bytes) inoperative size: 2147483648 " (1099511627776 bytes) Interestingly, between 1 Terabyte and 2 Terabyte, the virtual disk shows up, but without valid data. If you try to initialize the disk, Windows returns the error that the disk would be write protected. If it''s just one "LE" below full 2 Terabyte, it says "unsupported operation" instead. Hope that helps somehow... Keep up the good work, anyway :) Thanks, Björn Schneider James Harper schrieb:>> Hi, >> >> I''ve encountered a strange behaviour of the block device PV driver: with >> the Qemu-derived IO-emulation I can easily access both virtual drives of >> 50 GByte and 2 Terabyte. >> When I activate GPLPV, only the 50G system partition shows up; the 2 >> TByte one is completely absent. >> >> Is there a limit the GPLPV block driver can handle? -- everything else >> seems to work fine... and yes, I need that 2TByte disk. It''s a >> fileserver :) >> I could of course try to split the disk and use the Windows volume >> management to assemble it back -- but I don''t know how to do that >> exactly and it''d add another management layer. Which I don''t want to. >> >> Any ideas or maybe even a solution? :) But it''s not that urgent, I can >> still use the IO emulation until the system gets productive, which isn''t >> before January. And maybe even still then. >> > > What version of the drivers are you using, and also the exact sector count of the disk? > > 2TByte is exactly 2^32 * 512 byte sectors, eg right on the limit of the number of sectors a 32 bit integer can hold. I''ll have to check, but I may only be using the 32 bit SCSI commands... if you are actually just under 2TB then this probably won''t be the problem. > > James > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > >-- ==========================================================Björn Schneider, BSc. IT-Administration phone: +49 6221 33507 47 fax: +49 6221 33507 11 email: Bjoern.Schneider@tesa-scribos.de tesa scribos GmbH Sickingenstrasse 65 69126 Heidelberg Germany http://www.tesa-scribos.de Geschäftsführer: Dr. Christoph Dietrich, Dr. Steffen Noehte, Peter Kuich, Joachim Suesse (Vorsitzender) Registergericht Heidelberg HRB 337200 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
James Harper
2008-Nov-25 22:53 UTC
RE: [Xen-users] GPLPV-drivers: size limit in "hard disk drivers" forvolumes?
> Hi, > > I''m using the "Xen PV Drivers 0.9.12-pre4.exe" package on Windows 2008 > Server SP1 32bit. The Dom0 is Ubuntu 8.04LTS amd64 with Ubuntu''s kernel > 2.6.24-21-xen and Xen 3.2.1-rc1-pre. > > I''ve reduced the size down to a few sectors less than 1 Terabyte, and > now it works (couldn''t pin it down exactly to the sector limit, as LVM2 > uses ''LE units'' which contain several sectors). > > working size: 2147475456 sectors (1099507433472 bytes) > inoperative size: 2147483648 " (1099511627776 bytes) > > Interestingly, between 1 Terabyte and 2 Terabyte, the virtual disk shows > up, but without valid data. If you try to initialize the disk, Windows > returns the error that the disk would be write protected. If it''s just > one "LE" below full 2 Terabyte, it says "unsupported operation" instead. > > Hope that helps somehow... >Yes, I think that explains the problem just nicely. I''ll see what I can do, but it probably won''t be for another week or so. Thanks James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users