{ "created": "2015-12-20T19:56:49Z", "hierarchy": [ { "name": "ROOT", "type": "folder", "uri": "/ROOT" }, { "name": "Checksumming CD or DVD media", "type": "article", "uri": "Checksumming_CD_or_DVD_media" } ], "html": "\n\n \n \n \n \n\n \n \n\n \n \n \n \n \n\n Checksumming CD or DVD media\n\n \n \n \n \n
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Checksumming CD or DVD media

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Note on the MD5 command: On OS X, it’s md5. On RHEL it’s md5sum.

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Doing it properly

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Checksumming an ISO image is easy:

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[user@localhost ~]# md5sum centos-5.5.i386.iso  \n75c92246479df172de41b14c9b966344\n
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When you burn this to a DVD, you can verify that everything’s good by\nfirst getting the size of the ISO in bytes:

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[user@localhost ~]#  ls -l centos-5.5.i386.iso  \n-rw-r--r-- 1 user user 4185118720 May 20 15:40 centos-5.5.i386.iso\n
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Now divide that by 2048 (4185118720 √∑ 2048 = 2043515). You can now\nverify the DVD the ISO was burned to using:

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[user@localhost ~]# dd if=/dev/sdc bs=2048 count=2043515 | md5sum  \n75c92246479df172de41b14c9b966344\n
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This verifies a successful burn. Merely using dd if=/dev/sdc | md5sum\nwill always give you an incorrect checksum!

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\n \n \n \n \n \n\n", "id": "b28ac4d5-1e2f-5848-8479-a173e3c20247", "modified": "2022-06-13T23:23:48Z", "revisions": [ { "authorEmail": "mail@nikhil.io", "authorName": "Nikhil Anand", "date": "2022-06-13T23:23:48Z", "id": "6be928c4c8de048934c03e3c61539c9ceec7d59a", "shortId": "6be928c4", "subject": "Update config.yml", "content": "**Note on the MD5 command**: On OS X, it's `md5`. On RHEL it's `md5sum`.\n\n### Doing it properly\n\n* For this demo, I'll attempt to burn a CentOS 5.5 DVD\n* The ISO name is `centos-5.5.i386.iso`\n* It was burned to a DVD drive with device name `/dev/sdc`\n\nChecksumming an ISO image is easy:\n\n [user@localhost ~]# md5sum centos-5.5.i386.iso \n 75c92246479df172de41b14c9b966344\n\nWhen you burn this to a DVD, you can verify that everything's good by\nfirst getting the size of the ISO in bytes:\n\n [user@localhost ~]#  ls -l centos-5.5.i386.iso \n -rw-r--r-- 1 user user 4185118720 May 20 15:40 centos-5.5.i386.iso\n\nNow divide that by 2048 (4185118720 ÷ 2048 = 2043515). You can now\nverify the DVD the ISO was burned to using:\n\n [user@localhost ~]# dd if=/dev/sdc bs=2048 count=2043515 | md5sum \n 75c92246479df172de41b14c9b966344\n\nThis verifies a successful burn. Merely using `dd if=/dev/sdc | md5sum`\nwill *always* give you an incorrect checksum!\n" }, { "authorEmail": "mail@nikhil.io", "authorName": "Nikhil Anand", "date": "2015-12-27T07:27:56Z", "id": "5a5b1a32f41081d062ab86f8869a961bcad79668", "shortId": "5a5b1a32", "subject": "Fix Markdown conversion\n\nSaw half a season of The Office\n", "content": "**Note on the MD5 command**: On OS X, it's `md5`. On RHEL it's `md5sum`.\n\n### Doing it properly\n\n* For this demo, I'll attempt to burn a CentOS 5.5 DVD\n* The ISO name is `centos-5.5.i386.iso`\n* It was burned to a DVD drive with device name `/dev/sdc`\n\nChecksumming an ISO image is easy:\n\n [user@localhost ~]# md5sum centos-5.5.i386.iso \n 75c92246479df172de41b14c9b966344\n\nWhen you burn this to a DVD, you can verify that everything's good by\nfirst getting the size of the ISO in bytes:\n\n [user@localhost ~]#  ls -l centos-5.5.i386.iso \n -rw-r--r-- 1 user user 4185118720 May 20 15:40 centos-5.5.i386.iso\n\nNow divide that by 2048 (4185118720 ÷ 2048 = 2043515). You can now\nverify the DVD the ISO was burned to using:\n\n [user@localhost ~]# dd if=/dev/sdc bs=2048 count=2043515 | md5sum \n 75c92246479df172de41b14c9b966344\n\nThis verifies a successful burn. Merely using `dd if=/dev/sdc | md5sum`\nwill *always* give you an incorrect checksum!\n" }, { "authorEmail": "mail@nikhil.io", "authorName": "Nikhil Anand", "date": "2015-12-21T02:30:47Z", "id": "3f2c54b1d767218fcb4855fbac306b015afaf551", "shortId": "3f2c54b1", "subject": "Incremental\n", "content": "**Note on the MD5 command**: On OS X, it's `md5`. On RHEL it's `md5sum`.\nI'll use the latter for this guide.\n\n### Doing it properly\n\n- For this demo, I'll attempt to burn a CentOS 5.5 DVD\n- The ISO name is `centos-5.5.i386.iso`\n- It was burned to a DVD drive with device name `/dev/sdc`\n\nChecksumming an ISO image is easy:\n\n` [user@localhost ~]# md5sum centos-5.5.i386.iso` \n` 75c92246479df172de41b14c9b966344`\n\nWhen you burn this to a DVD, you can verify that everything's good by\nfirst getting the size of the ISO in bytes:\n\n` [user@localhost ~]#  ls -l centos-5.5.i386.iso` \n` -rw-r--r-- 1 user user 4185118720 May 20 15:40 centos-5.5.i386.iso`\n\nNow divide that by 2048 (4185118720 ÷ 2048 = 2043515). You can now\nverify the DVD the ISO was burned to using:\n\n` [user@localhost ~]# dd if=/dev/sdc `**`bs=2048`**` `**`count=2043515`**` | md5sum` \n` 75c92246479df172de41b14c9b966344`\n\nThis verifies a successful burn. Merely using `dd if=/dev/sdc | md5sum`\nwill *always* give you an incorrect checksum!\n\n\n\n" }, { "authorEmail": "mail@nikhil.io", "authorName": "Nikhil Anand", "date": "2015-12-20T19:56:49Z", "id": "0ce1b8085698af22657aee11b2c6776fa73ab8da", "shortId": "0ce1b808", "subject": "Checksumming CD or DVD media : First Draft", "content": "**Note on the MD5 command**: On OS X, it's `md5`. On RHEL it's `md5sum`.\nI'll use the latter for this guide.\n\n### Doing it properly\n\n- For this demo, I'll attempt to burn a CentOS 5.5 DVD\n- The ISO name is `centos-5.5.i386.iso`\n- It was burned to a DVD drive with device name `/dev/sdc`\n\nChecksumming an ISO image is easy:\n\n` [user@localhost ~]# md5sum centos-5.5.i386.iso` \n` 75c92246479df172de41b14c9b966344`\n\nWhen you burn this to a DVD, you can verify that everything's good by\nfirst getting the size of the ISO in bytes:\n\n` [user@localhost ~]#  ls -l centos-5.5.i386.iso` \n` -rw-r--r-- 1 user user 4185118720 May 20 15:40 centos-5.5.i386.iso`\n\nNow divide that by 2048 (4185118720 ÷ 2048 = 2043515). You can now\nverify the DVD the ISO was burned to using:\n\n` [user@localhost ~]# dd if=/dev/sdc `**`bs=2048`**` `**`count=2043515`**` | md5sum` \n` 75c92246479df172de41b14c9b966344`\n\nThis verifies a successful burn. Merely using `dd if=/dev/sdc | md5sum`\nwill *always* give you an incorrect checksum!\n\n[Category:Nikhil's Notes](Category:Nikhil's_Notes \"wikilink\")\n[Category:From a past sysadmin\nlife](Category:From_a_past_sysadmin_life \"wikilink\")\n" } ], "sizeInBytes": 983, "source": "**Note on the MD5 command**: On OS X, it's `md5`. On RHEL it's `md5sum`.\n\n### Doing it properly\n\n* For this demo, I'll attempt to burn a CentOS 5.5 DVD\n* The ISO name is `centos-5.5.i386.iso`\n* It was burned to a DVD drive with device name `/dev/sdc`\n\nChecksumming an ISO image is easy:\n\n [user@localhost ~]# md5sum centos-5.5.i386.iso \n 75c92246479df172de41b14c9b966344\n\nWhen you burn this to a DVD, you can verify that everything's good by\nfirst getting the size of the ISO in bytes:\n\n [user@localhost ~]#  ls -l centos-5.5.i386.iso \n -rw-r--r-- 1 user user 4185118720 May 20 15:40 centos-5.5.i386.iso\n\nNow divide that by 2048 (4185118720 ÷ 2048 = 2043515). You can now\nverify the DVD the ISO was burned to using:\n\n [user@localhost ~]# dd if=/dev/sdc bs=2048 count=2043515 | md5sum \n 75c92246479df172de41b14c9b966344\n\nThis verifies a successful burn. Merely using `dd if=/dev/sdc | md5sum`\nwill *always* give you an incorrect checksum!\n", "title": "Checksumming CD or DVD media", "untracked": false, "uri": "/Checksumming_CD_or_DVD_media" }