Reaching Beyond Two-Terabyte Filesystems

Jeremy Andrews writes: "Peter Chubb posted a patch to the lkml, with which he's now managed to mount a 15 terabyte file (using JFS and the loopback device). Without the patch, Peter explains, "Linux is limited to 2TB filesystems even on 64-bit systems, because there are various places where the block offset on disc are assigned to unsigned or int 32-bit variables." Peter works on the Gelato project in Australia. His efforts include cleaning up Linux's large filesystem support, removing 32-bit filesystem limitations. When I asked him about the new 64-bit filesystem limits, he offered a comprehensive answer and this interesting link. The full thread can be found here on KernelTrap. Reaching beyond terabytes, beyond pentabytes, on into exabytes. I feel this sudden discontent with my meager 60 gigabyte hard drive..."

Comments

xfs for linux

[mysticbob]

xfs for linux has provided significantly larger than 2Tb filesystems for a while. the official size supported is:

26^3 = 9 x 10^18 = 9 exabytes

check out the feature list.

arithmetic?

[Anonymous Coward]

For those who wish to communicate with the rest of the world, the following calculations actually make sense:

• 10^18 bytes = 1 000 000 000 000 000 bytes = 1 decimal terabyte = 1 terabyte = 1 TB
• 2^50 bytes = 1 125 899 906 842 624 bytes = 1 binary terabyte = 1 tebibyte = 1 TiB

For the uninitiated, these terms are described here

Even accounting for your typographical error, 2^63 != 9 * 10^18 (9223372036854775808 != 9000000000000000000)