Re: Does Linux support more than 2TB on a USB attached device?
"Richard Sharpe" <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
>> scsi_host_alloc creates a host structure with max_cmd_len >> set to 12. >> >> To allow USB Storage to accept 16-byte CDBs, the following will >> >> need to be added: >> >> host->max_cmd_len = 16; /* or some symbol */ >> >> That should allow for USB storage devices larger than 2TiB. >The question is whether USB storage as a specification permits this, >and what other hardware does if this happens. As far as I am aware the spec is silent on this issue. In any event, this is standard SCSI. The host sends a READ_CAPACITY(10) and if it receives a MAX LBA less than 0xFFFFFFFF it never submits 16-byte CDBs. If the device sends back 0xFFFFFFFF the host sends a READ_CAPACITY(16) and gets the real size and can then send 16-byte CDBs. Mac OS X and Vista have no problems with this and work with USB Storage devices that do <= 2TiB as well as our device. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel