Trim (computing)

TRIM is a command for marking unused or invalid data blocks on storage media to the subsequent rewriting.

The TRIM command allows an operating system, the storage medium Solid -State Drive (SSD ) to announce that deleted or otherwise vacant blocks are no longer used. Normally, the operating system recognized only in the administrative structures of the file system that the corresponding ranges are for new data is available; However, the controller of the solid-state drive does not receive this information in the rule.

Through the ATA TRIM command to the drive when you delete files is informed that it can mark the affected blocks as invalid vorzuhalten further instead their data. The contents are no longer co-written, so the write access speeds on the drive and also the wear effects are reduced. The blocks are then marked invalid at the next clearing its Erasable Blocks free. TRIM was introduced for the Linux operating system kernel version 2.6.33, Windows 7 also has the appropriate commands. For Mac OS X since version 10.6.8 is also an implementation of this intelligent storage management for general use, but only for SSDs that came pre-installed by Apple. However, there are solutions that can also be activated for subsequently installed SSDs with TRIM.

This function can also be used when no real hardware is involved: On Linux, the device mapper, this erasure information of the file system also recycled. Here it comes to save (typically overcrowded ) space.

FreeBSD 8.2 ( Full support in UFS)

January 29, 2011