1*4882a593Smuzhiyun.. SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun 3*4882a593Smuzhiyun====================================== 4*4882a593SmuzhiyunLinux SCSI Disk Driver (sd) Parameters 5*4882a593Smuzhiyun====================================== 6*4882a593Smuzhiyun 7*4882a593Smuzhiyuncache_type (RW) 8*4882a593Smuzhiyun--------------- 9*4882a593SmuzhiyunEnable/disable drive write & read cache. 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun=========================== === === =========== ========== 12*4882a593Smuzhiyun cache_type string WCE RCD Write cache Read cache 13*4882a593Smuzhiyun=========================== === === =========== ========== 14*4882a593Smuzhiyun write through 0 0 off on 15*4882a593Smuzhiyun none 0 1 off off 16*4882a593Smuzhiyun write back 1 0 on on 17*4882a593Smuzhiyun write back, no read (daft) 1 1 on off 18*4882a593Smuzhiyun=========================== === === =========== ========== 19*4882a593Smuzhiyun 20*4882a593SmuzhiyunTo set cache type to "write back" and save this setting to the drive:: 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun # echo "write back" > cache_type 23*4882a593Smuzhiyun 24*4882a593SmuzhiyunTo modify the caching mode without making the change persistent, prepend 25*4882a593Smuzhiyun"temporary " to the cache type string. E.g.:: 26*4882a593Smuzhiyun 27*4882a593Smuzhiyun # echo "temporary write back" > cache_type 28