Date: Fri, 22 Jul 2016 15:51:19 -0500 From: Karl Denninger <karl@denninger.net> To: "freebsd-fs@freebsd.org" <freebsd-fs@freebsd.org> Subject: Re: ZFS, SSD and encryption Message-ID: <c2f03984-3e98-a698-80f2-af989f53cd52@denninger.net> In-Reply-To: <CAASnNnq34crTVMoqkUhqhccYkajDT=grfMKaeWQB466P78BJOw@mail.gmail.com> References: <CAJPDrRtLBNKr4BynSGMRfFGdAR0ZbDuwfcqkLupvk5HtgqrbQg@mail.gmail.com> <b8b000ff-289c-7348-8b63-00f3ac51accf@denninger.net> <CAASnNnpnST%2BD6fVT%2BFrH%2BomkwNQb4rG1NJk0T=O2AetzrXEThA@mail.gmail.com> <c52ebaa8-e82b-1a17-d868-52c40032c3d5@denninger.net> <CAASnNnq34crTVMoqkUhqhccYkajDT=grfMKaeWQB466P78BJOw@mail.gmail.com>
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This is a cryptographically signed message in MIME format. --------------ms000908070301090802060904 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 7/22/2016 15:10, Eric A. Borisch wrote: > On Fri, Jul 22, 2016 at 2:27 PM, Karl Denninger <karl@denninger.net> wr= ote: >> On 7/22/2016 14:02, Eric A. Borisch wrote: >>> On Friday, July 22, 2016, Karl Denninger <karl@denninger.net >>> <mailto:karl@denninger.net>> wrote: >>> >>> >>> On 7/22/2016 07:48, Nikos Kastanas wrote: >>> > I have a Lenovo X220 laptop running FreeBSD 10.3-RELEASE with >>> ZFS and >>> > encryption on a plain HDD. I am considering buying a Samsung Pr= o >>> 850 SSD to >>> > boost performance but I am not sure if TRIM and ZFS+Encryption >>> work well >>> > together. After some research online, I found *this page* >>> > <https://www.freebsd.org/doc/faq/all-about-zfs.html>which state= s the >>> > following: >>> > >>> > *Note: * >>> > ZFS TRIM may not work with all configurations, such as a ZFS >>> filesystem on >>> > a GELI-backed device. >>> > >>> > From what I can understand from the above note, I should not us= e the >>> > encryption option when installing FreeBSD with ZFS on an SSD. >>> TRIM will not >>> > work correctly and therefore the SSD performace will be impacte= d. >>> Meh. Simply not true. >>> >>> >>> It will not work on 10.3, but will work (as Karl demonstrates) on >>> 11.x. Here's the commit to head enabling it: >>> >>> https://svnweb.freebsd.org/base?view=3Drevision&revision=3D286444 >>> >>> And here's what is in 10.3 (BIO_DELETE case returns EOPNOTSUPP): >>> >>> https://svnweb.freebsd.org/base/releng/10.3/sys/geom/eli/g_eli.c?revi= sion=3D296373&view=3Dmarkup#l319 >>> >>> - Eric >> Note that the system in question (from which the stats were pulled) wa= s >> on 10.2 for an extended period of time, with SSDs, and with >> Geli-encrypted disks. It was fine with no performance issues; whether= >> there is a problem with earlier releases has much to do with the disks= >> in question. >> >> In the case of the Intel 730s it works perfectly well even though TRIM= >> is not passed through in that case. > Fair, but the original question was if "TRIM will not work correctly > and therefore the SSD performace will be impacted" -- and the answer > is that TRIM+GELI does not "work correctly" for 10.3, but it does for > 11.x. This is only a performance (and not "is my data safe") > statement. > > As you allude to, how much this impacts performance depends on the > drive, partitioning / provisioning, and workload. > > - Eric Note the two-part original statement-of-claim. 1. TRIM will not work on GELI encrypted disks before 11.x (true) 2. Performance will be severely impacted due to #1 (not necessarily and, with proper SSD selection, generally false) This is far more dependent on the SSD in question than the workload.=20 The machine from which those stats were pulled, now on 11.0-BETA1, was on 10.2-STABLE for an extended period of time and has production loads on it, including quite-heavy Postgresql DBMS use with a lot of table write activity. I never saw any evidence of performance degradation at all over that time, and it has run with GELI-encrypted providers since I stuffed AESNI-equipped processors in that particular machine (making FDE reasonable in terms of CPU overhead) a few years back. It just happens to be that one of the good choices in SSD selection from a standpoint of not having performance go to hell correlates with your data being safe as well. I'm sure there are corner cases where #2 is true even with a carefully-considered SSD selection but in the time I've been using the Intel 730s I've not run into them. The big benefit of TRIM is that by immediately notifying the drive of a "freed" block it is able to choose how and when to consolidate and pre-erase said blocks for later use. Since NVRAM has to be erased in fairly large blocks (frequently 4MB in size or even more) to be re-written and the erase cycle is, relatively speaking, somewhat slow being able to do this "in advance" of the demand to write a block can bring quite-material performance improvements. In addition, due to the relatively large unit of erasure vis-a-vis the typical allocation size on a file system there are a lot of other storage management considerations that come into play; being able to do some or all of that before the user demands a new block be written can be of great benefit to performance. But exactly how much this matters is dependent on many things with one of the most-important being how well the microcode in the drive is written in the first place...... I suspect the odds of running into performance trouble in the OP's environment, that being a laptop-style computer for what are probably "personal" (as opposed to "server") sort of workloads, if the OP uses one of the Intel 730s as the SSD in question, approaches zero -- and of course somewhere down the road the OP will probably roll forward to 11.x.= --=20 Karl Denninger karl@denninger.net <mailto:karl@denninger.net> /The Market Ticker/ /[S/MIME encrypted email preferred]/ --------------ms000908070301090802060904 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Bl8wggZbMIIEQ6ADAgECAgEpMA0GCSqGSIb3DQEBCwUAMIGQMQswCQYDVQQGEwJVUzEQMA4G A1UECBMHRmxvcmlkYTESMBAGA1UEBxMJTmljZXZpbGxlMRkwFwYDVQQKExBDdWRhIFN5c3Rl bXMgTExDMRwwGgYDVQQDExNDdWRhIFN5c3RlbXMgTExDIENBMSIwIAYJKoZIhvcNAQkBFhND dWRhIFN5c3RlbXMgTExDIENBMB4XDTE1MDQyMTAyMjE1OVoXDTIwMDQxOTAyMjE1OVowWjEL MAkGA1UEBhMCVVMxEDAOBgNVBAgTB0Zsb3JpZGExGTAXBgNVBAoTEEN1ZGEgU3lzdGVtcyBM TEMxHjAcBgNVBAMTFUthcmwgRGVubmluZ2VyIChPQ1NQKTCCAiIwDQYJKoZIhvcNAQEBBQAD ggIPADCCAgoCggIBALmEWPhAdphrWd4K5VTvE5pxL3blRQPyGF3ApjUjgtavqU1Y8pbI3Byg XDj2/Uz9Si8XVj/kNbKEjkRh5SsNvx3Fc0oQ1uVjyCq7zC/kctF7yLzQbvWnU4grAPZ3IuAp 3/fFxIVaXpxEdKmyZAVDhk9az+IgHH43rdJRIMzxJ5vqQMb+n2EjadVqiGPbtG9aZEImlq7f IYDTnKyToi23PAnkPwwT+q1IkI2DTvf2jzWrhLR5DTX0fUYC0nxlHWbjgpiapyJWtR7K2YQO aevQb/3vN9gSojT2h+cBem7QIj6U69rEYcEDvPyCMXEV9VcXdcmW42LSRsPvZcBHFkWAJqMZ Myiz4kumaP+s+cIDaXitR/szoqDKGSHM4CPAZV9Yh8asvxQL5uDxz5wvLPgS5yS8K/o7zDR5 vNkMCyfYQuR6PAJxVOk5Arqvj9lfP3JSVapwbr01CoWDBkpuJlKfpQIEeC/pcCBKknllbMYq yHBO2TipLyO5Ocd1nhN/nOsO+C+j31lQHfOMRZaPQykXVPWG5BbhWT7ttX4vy5hOW6yJgeT/ o3apynlp1cEavkQRS8uJHoQszF6KIrQMID/JfySWvVQ4ksnfzwB2lRomrdrwnQ4eG/HBS+0l eozwOJNDIBlAP+hLe8A5oWZgooIIK/SulUAsfI6Sgd8dTZTTYmlhAgMBAAGjgfQwgfEwNwYI KwYBBQUHAQEEKzApMCcGCCsGAQUFBzABhhtodHRwOi8vY3VkYXN5c3RlbXMubmV0Ojg4ODgw CQYDVR0TBAIwADARBglghkgBhvhCAQEEBAMCBaAwCwYDVR0PBAQDAgXgMCwGCWCGSAGG+EIB DQQfFh1PcGVuU1NMIEdlbmVyYXRlZCBDZXJ0aWZpY2F0ZTAdBgNVHQ4EFgQUxRyULenJaFwX RtT79aNmIB/u5VkwHwYDVR0jBBgwFoAUJHGbnYV9/N3dvbDKkpQDofrTbTUwHQYDVR0RBBYw FIESa2FybEBkZW5uaW5nZXIubmV0MA0GCSqGSIb3DQEBCwUAA4ICAQBPf3cYtmKowmGIYsm6 eBinJu7QVWvxi1vqnBz3KE+HapqoIZS8/PolB/hwiY0UAE1RsjBJ7yEjihVRwummSBvkoOyf G30uPn4yg4vbJkR9lTz8d21fPshWETa6DBh2jx2Qf13LZpr3Pj2fTtlu6xMYKzg7cSDgd2bO sJGH/rcvva9Spkx5Vfq0RyOrYph9boshRN3D4tbWgBAcX9POdXCVfJONDxhfBuPHsJ6vEmPb An+XL5Yl26XYFPiODQ+Qbk44Ot1kt9s7oS3dVUrh92Qv0G3J3DF+Vt6C15nED+f+bk4gScu+ JHT7RjEmfa18GT8DcT//D1zEke1Ymhb41JH+GyZchDRWtjxsS5OBFMzrju7d264zJUFtX7iJ 3xvpKN7VcZKNtB6dLShj3v/XDsQVQWXmR/1YKWZ93C3LpRs2Y5nYdn6gEOpL/WfQFThtfnat HNc7fNs5vjotaYpBl5H8+VCautKbGOs219uQbhGZLYTv6okuKcY8W+4EJEtK0xB08vqr9Jd0 FS9MGjQE++GWo+5eQxFt6nUENHbVYnsr6bYPQsZH0CRNycgTG9MwY/UIXOf4W034UpR82TBG 1LiMsYfb8ahQJhs3wdf1nzipIjRwoZKT1vGXh/cj3gwSr64GfenURBxaFZA5O1acOZUjPrRT n3ci4McYW/0WVVA3lDGCBRMwggUPAgEBMIGWMIGQMQswCQYDVQQGEwJVUzEQMA4GA1UECBMH RmxvcmlkYTESMBAGA1UEBxMJTmljZXZpbGxlMRkwFwYDVQQKExBDdWRhIFN5c3RlbXMgTExD MRwwGgYDVQQDExNDdWRhIFN5c3RlbXMgTExDIENBMSIwIAYJKoZIhvcNAQkBFhNDdWRhIFN5 c3RlbXMgTExDIENBAgEpMA0GCWCGSAFlAwQCAwUAoIICTTAYBgkqhkiG9w0BCQMxCwYJKoZI hvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xNjA3MjIyMDUxMTlaME8GCSqGSIb3DQEJBDFCBECg o1ZeOCw0u2y1txAQbHH0csHRi1XXV7/AoxlFue6EbVa9ESoD44XbVBHRCaC2hdZwaHNOqOXw bsQHSxZ+yXEAMGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEqMAsGCWCGSAFlAwQBAjAK BggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwICAUAwBwYFKw4DAgcwDQYI KoZIhvcNAwICASgwgacGCSsGAQQBgjcQBDGBmTCBljCBkDELMAkGA1UEBhMCVVMxEDAOBgNV BAgTB0Zsb3JpZGExEjAQBgNVBAcTCU5pY2V2aWxsZTEZMBcGA1UEChMQQ3VkYSBTeXN0ZW1z IExMQzEcMBoGA1UEAxMTQ3VkYSBTeXN0ZW1zIExMQyBDQTEiMCAGCSqGSIb3DQEJARYTQ3Vk YSBTeXN0ZW1zIExMQyBDQQIBKTCBqQYLKoZIhvcNAQkQAgsxgZmggZYwgZAxCzAJBgNVBAYT AlVTMRAwDgYDVQQIEwdGbG9yaWRhMRIwEAYDVQQHEwlOaWNldmlsbGUxGTAXBgNVBAoTEEN1 ZGEgU3lzdGVtcyBMTEMxHDAaBgNVBAMTE0N1ZGEgU3lzdGVtcyBMTEMgQ0ExIjAgBgkqhkiG 9w0BCQEWE0N1ZGEgU3lzdGVtcyBMTEMgQ0ECASkwDQYJKoZIhvcNAQEBBQAEggIAslI71n2e mnazf0TeI21I1Ved/+iOFCqEHNFipV+2DI4E2dsm7aq7Z9WVmF+wujppJvBdHNZcKJAVzpoB rysEzLu9yjrY003yPzxfsBIETaOyPzY5LMxuny5jegbXFxfpXrJwM40toYY4fQPsQokjP94X 2iPxf1LKb5lrPXK+ithbXQS26jfmp9UDGLb2kbWaUsOG7xFo+jkrSh+RFquYb2XRTJD/wbGK dRkrD3r8goRIWUu1g0EpBakCrHhmel5iFym2ef1KrwQJ2ME14VRyTslI8T22dtzoA7bFcnPA XhwQJtr4lUs7rg/SzCixt+mOx/RKpJEKdPmxEvXpgPYQOjKEgHlfpzvVuBs2DhzExNBwP9Gv 8NkRdrKXYbLkMBrxjKMHxgbvti65LjfOLDCA+4KHCfCwqMd3U9OKUFX/Ya23gheBUZzGRXt2 Aw4FWmFuuF1prH/8AUDBvbXFC5CSSTvA0IAVUGPlkAKAzX3Q/Qwkoqd6rGaA5PNybjYLwzv3 kY+gZsnPqMoX8w8HYQV2dga/hx5UFic4qjKX1lVOjGCfVEQbL9T8dPals0iEAox6GQkHNim3 iaEq3Bm1VTJtGunkiHy9PFcFDPSaycJtprBezgVV9Wrb76WWL1xQ/rvathOmAqN2AcCFa6cJ FN5qvFp4gGf+yd7aATLDQeKqubEAAAAAAAA= --------------ms000908070301090802060904--
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