Date: Tue, 5 Dec 2017 10:50:43 -0600 From: Dustin Wenz <dustinwenz@ebureau.com> To: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> Cc: Paul Vixie <paul@redbarn.org>, FreeBSD virtualization <freebsd-virtualization@freebsd.org> Subject: Re: Storage overhead on zvols Message-ID: <3AABC35B-FA6C-4DC6-B70C-F6D1326A7D25@ebureau.com> In-Reply-To: <201712051641.vB5GfR5I052310@pdx.rh.CN85.dnsmgr.net> References: <201712051641.vB5GfR5I052310@pdx.rh.CN85.dnsmgr.net>
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--Apple-Mail=_EB8E0C23-94DF-4B05-B0CF-B54FC3AFB16B Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii > On Dec 5, 2017, at 10:41 AM, Rodney W. Grimes = <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> wrote: >=20 >>=20 >>=20 >> Dustin Wenz wrote: >>> I'm not using ZFS in my VMs for data integrity (the host already >>> provides that); it's mainly for the easy creation and management of >>> filesystems, and the ability to do snapshots for rollback and >>> replication. >>=20 >> snapshot and replication works fine on the host, acting on the zvol. >=20 > I suspect he is snapshotting and doing send/recvs of something > much less than the zvol, probably some datasetbs, maybe boot > envorinments, a snapshot of the whole zvol is ok if your managing > data at the VM level, not so good if you got lots of stuff going > on inside the VM. Exactly, it's useful to have control of each filesystem discretely. >>> Some of my deployments have hundreds of filesystems in >>> an organized hierarchy, with delegated permissions and automated >>> snapshots, send/recvs, and clones for various operations. >>=20 >> what kind of zpool do you use in the guest, to avoid unwanted = additional=20 >> redundancy? >=20 > Just a simple stripe of 1 device would be my guess, though your > still gona have metadata redundancy. Also correct; just using the zvol virtual device as a single-disk pool. >>=20 >> did you benchmark the space or time efficiency of ZFS vs. UFS? >>=20 >> in some bsd related meeting this year i asked allan jude for a bhyve=20= >> level null mount, so that we could access at / inside the guest some=20= >> subtree of the host, and avoid block devices and file systems=20 >> altogether. right now i have to use nfs for that, which is = irritating. >=20 > This is not as simple as it seems, remember bhyve is just presenting > a hardware environment, hardware environments dont have a file system > concept per se, unlike jails which are providing a software = environment. >=20 > In effect what your asking for is what NFS does, so use NFS and get > over the fact that this is the way to get what you want. Sure you > could implement a virt-vfs but I wonder how close the spec of that > would be to the spec of NFS. >=20 > Or maybe thats the answer, implement virt-vfs as a more effecient way > to transport nfs calls in and out of the guest. I've not done any deliberate comparisons for latency or throughput. What = I've decided to virtualize does not have any exceptional performance = requirements. If I need the best possible IO, I would lean toward using = jails instead of a hypervisor. - .Dustin --Apple-Mail=_EB8E0C23-94DF-4B05-B0CF-B54FC3AFB16B Content-Disposition: attachment; filename=smime.p7s Content-Type: application/pkcs7-signature; name=smime.p7s Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIEzDCCBMgw ggOwoAMCAQICAUEwDQYJKoZIhvcNAQELBQAwgZkxCzAJBgNVBAYTAlVTMRIwEAYDVQQIEwlNaW5u ZXNvdGExFDASBgNVBAcTC1NhaW50IENsb3VkMRAwDgYDVQQKEwdlQnVyZWF1MRQwEgYDVQQLEwtJ bnRlZ3JhdGlvbjEUMBIGA1UEAxMLZWJ1cmVhdS5jb20xIjAgBgkqhkiG9w0BCQEWE3N1cHBvcnRA ZWJ1cmVhdS5jb20wHhcNMTcwNTA1MTYxNjE1WhcNMjcwNTAzMTYxNjE1WjBKMQswCQYDVQQGEwJV UzEUMBIGA1UEAwwLRHVzdGluIFdlbnoxJTAjBgkqhkiG9w0BCQEWFmR1c3RpbndlbnpAZWJ1cmVh dS5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCQ/HJXe7JhUaexqEaxCNVifsue sUMgohgXLmi5YIcbAWhdxTr1PUzKYkeTkL9sYNjXU6uaI2tZMF3hA9gcFjxQIfkKSo31MrYOgMdU xQe0Q+t6Vd4pGAmtDQDwhAsrNGccADp3Yjy4eBtVfkDGdzz1Y8Lbc684TPFcW7i9+U/dDaXlcxeq fyDqiHZ5y8Lp/1M2Ot/Rz7eikJZTAuHOWKs/PEiJIM2JHuhPyNy+mL2oqEWeOcEsKMNzgn7HVt4k Xz2irBAG+cj4WAxWs418l46EEXgur4PvhBXZMl0LJg0TyaxOHbsUam4R4tbKnaZ3HhRkg79k2Had sb6DKbnCw9/1AgMBAAGjggFnMIIBYzAJBgNVHRMEAjAAMAsGA1UdDwQEAwIE8DAnBgNVHSUEIDAe BggrBgEFBQcDAQYIKwYBBQUHAwIGCCsGAQUFBwMEMB0GA1UdDgQWBBTLi/8HUHpbBEt9OtPqQoax AmpaNDCBzgYDVR0jBIHGMIHDgBRnpZeXB5rQYLgsUKqiiBcLIHyu6aGBn6SBnDCBmTELMAkGA1UE BhMCVVMxEjAQBgNVBAgTCU1pbm5lc290YTEUMBIGA1UEBxMLU2FpbnQgQ2xvdWQxEDAOBgNVBAoT B2VCdXJlYXUxFDASBgNVBAsTC0ludGVncmF0aW9uMRQwEgYDVQQDEwtlYnVyZWF1LmNvbTEiMCAG CSqGSIb3DQEJARYTc3VwcG9ydEBlYnVyZWF1LmNvbYIJAMwZcjAWAsWXMDAGCWCGSAGG+EIBBAQj FiFodHRwOi8vd3d3LmVidXJlYXUuY29tL2NhLWNybC5wZW0wDQYJKoZIhvcNAQELBQADggEBAHbO qVdB9raUKXCgZRA/nES5a60dlIaGnIlpgz+Y3SjFt0bcJxoUYhIzumBHk9yjyP4M1DubOphkQpJ4 LNZbAS01cjCxjnC0ZUq5V3FCeaDwrn1qPY+QJGoZPLlhWdJUNu17OpnR7ZfBWlp3/pRhvNU5PCbJ nmF7rnvsqxUFq9oeiV3SmqBux5lwJ7p2Uss5SHSW6g17K/KdTMK1roQr/+rWpxp2233qddDrLpOE xGRlvhEqSa/IZbGC9oiYmsiaG1PefQkadoob5IMIS5/MDpWHUgSHqAj1V/LwcCx0rbt73SazGMND EzHVWhsj+khepB/MG5QGfWP23IGFmvQYWWcxggOQMIIDjAIBATCBnzCBmTELMAkGA1UEBhMCVVMx EjAQBgNVBAgTCU1pbm5lc290YTEUMBIGA1UEBxMLU2FpbnQgQ2xvdWQxEDAOBgNVBAoTB2VCdXJl YXUxFDASBgNVBAsTC0ludGVncmF0aW9uMRQwEgYDVQQDEwtlYnVyZWF1LmNvbTEiMCAGCSqGSIb3 DQEJARYTc3VwcG9ydEBlYnVyZWF1LmNvbQIBQTAJBgUrDgMCGgUAoIIBxTAYBgkqhkiG9w0BCQMx CwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xNzEyMDUxNjUwNDNaMCMGCSqGSIb3DQEJBDEW BBRqFkf4l9VzQL/9GCAzc82q7JG0qDCBsAYJKwYBBAGCNxAEMYGiMIGfMIGZMQswCQYDVQQGEwJV UzESMBAGA1UECBMJTWlubmVzb3RhMRQwEgYDVQQHEwtTYWludCBDbG91ZDEQMA4GA1UEChMHZUJ1 cmVhdTEUMBIGA1UECxMLSW50ZWdyYXRpb24xFDASBgNVBAMTC2VidXJlYXUuY29tMSIwIAYJKoZI hvcNAQkBFhNzdXBwb3J0QGVidXJlYXUuY29tAgFBMIGyBgsqhkiG9w0BCRACCzGBoqCBnzCBmTEL MAkGA1UEBhMCVVMxEjAQBgNVBAgTCU1pbm5lc290YTEUMBIGA1UEBxMLU2FpbnQgQ2xvdWQxEDAO BgNVBAoTB2VCdXJlYXUxFDASBgNVBAsTC0ludGVncmF0aW9uMRQwEgYDVQQDEwtlYnVyZWF1LmNv bTEiMCAGCSqGSIb3DQEJARYTc3VwcG9ydEBlYnVyZWF1LmNvbQIBQTANBgkqhkiG9w0BAQEFAASC AQBWZeELFOLYPi3obweR2RMGGmtuzE1T2JMJoPE7oAdCHKpWYKiiAQufsCmKnfezrXS6XMRzbXPx GLfAVigvz10XjBkCXO6pJw4FWP6VeWovLagFrulhSn4BEcMy8uGkrgdDc6gN9TKne/TYEPrbBCjX wc8Nj+ovDVeZLwpBSi2uGHpVIEH+eMN4FLVOD29L1rar6hUEej8WKJil0u565DVO+5q6DI82/3YZ BIbUzvXfmCNtXErNmFaMxILCZEPhhlOv7pNrgL4WrfP+poMVuSx9lXPDhEx0JftEzPUDdm77nTfk X8iMINn6Uo8JsPTbyib73087L4akVqOqFGUT+OfUAAAAAAAA --Apple-Mail=_EB8E0C23-94DF-4B05-B0CF-B54FC3AFB16B--
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