{"id":3728,"date":"2014-11-17T07:04:42","date_gmt":"2014-11-16T23:04:42","guid":{"rendered":"http:\/\/rmohan.com\/?p=3728"},"modified":"2014-11-17T07:04:42","modified_gmt":"2014-11-16T23:04:42","slug":"mbr-vs-gpt","status":"publish","type":"post","link":"https:\/\/mohan.sg\/?p=3728","title":{"rendered":"MBR vs GPT"},"content":{"rendered":"

MBR is the standard partitioning scheme that\u2019s been used on hard disks since the PC first came out. It supports 4 primary partitions per hard drive, and a maximum partition size of 2TB.<\/p>\n

GPT disks are new, and are readable only by Windows Server 2003 SP1, Windows Vista (all versions), and Windows XP x64 Edition. The GPT disk itself can support a volume up to 2^64 blocks in length. (For 512-byte blocks, this is 9.44 ZB \u2013 zettabytes. 1 ZB is 1 billion terabytes). It can also support theoretically unlimited partitions.<\/p>\n

Windows restricts these limits further to 256 TB for a single partition (NTFS limit), and 128 partitions.<\/p>\n

Only Itanium systems running Windows Server 2003 and Windows Vista systems with an EFI BIOS can boot from a GPT disk. The other operating systems mentioned earlier can use GPT disks as data disks but not boot disks.<\/p>\n

MBR Disk Layout<\/p>\n

The following diagram from the Microsoft TechNet Library provides an example of a typical MBR disk layout<\/p>\n

\"MBR\"<\/a><\/p>\n

Figure 1: MBR Disk Layout<\/p>\n

Perhaps one of the biggest pitfalls of MBR-based disks is their potential for corruption of the partition table, a region on the disk that maps sectors to logical block numbers. MBR disks only have 1 partition table to keep track of all the blocks in the partition. If the table becomes corrupt, the entire disk must be recovered from backup. Windows GPT-based disks have multiple, redundant partition tables so that if one is detected as being corrupt, it can self-heal itself from a redundant copy of the table.<\/p>\n

For compatibility purposes, the Master Boot Record is kept at LBA 0 in GPT-based drives, and the GPT header begins at LBA 1. The partition type of a GPT disk is marked as 0xEE, which prevents MBR-based disk utilities from recognizing the partition type and potentially corrupting the data. It is possible to convert an MBR disk to a GPT-based disk and vice versa, but any data must first be backed up and all the partitions deleted.<\/p>\n

GPT-based Disk Layout<\/p>\n

The following diagram from the Microsoft TechNet Library provides an example of the disk layout for a GPT-based disk.
\n\"GPT\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

MBR is the standard partitioning scheme that\u2019s been used on hard disks since the PC first came out. It supports 4 primary partitions per hard drive, and a maximum partition size of 2TB.<\/p>\n

GPT disks are new, and are readable only by Windows Server 2003 SP1, Windows Vista (all versions), and Windows XP x64 Edition. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,4],"tags":[],"_links":{"self":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/3728"}],"collection":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3728"}],"version-history":[{"count":1,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/3728\/revisions"}],"predecessor-version":[{"id":3731,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/3728\/revisions\/3731"}],"wp:attachment":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3728"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3728"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3728"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}