Sage Weil <sage <at> newdream.net> writes: > > > My question is: > > > The SCSI LLD would support both read /write entry points for I/O > > > requests issued by the filesystem/block I/O but they also support some > > > custom requests using IOCTLs. So how can ceph support issuing of such > > > IOCTL requests to the device if user issues such request. Say for > > > example power cycling the drive etc. It can also be a passthro request > > > down to the device. > > Can you give an example of such an operation? > > In general, any operation is generalized at the librados level. > For example, in order to get write same and cmpxchg block operations, we > added librados operations with similar semantics and implement them there. > It is unlikely that passing a complex operation down to the SCSI layer > will work in unison with the other steps involved in committing > an operation (e.g., updating metadata indicating the object > version has changed). > > sage > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo <at> vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Thanks for the response Sage. Example IOCTL operations would be like downloading a new FW to the drive/HBA, task management requests like Hard reset, power cycling the drive, issue a SAS/SMP/STP pass thro command to the drive for querying etc. All these would have to be initiated and go through ceph (if supported) and not bypassing it. I asked a related question in another post too: Can a physical disk (/dev/sda1) assigned to a ceph OSD object be continued to used by other apps in the system to issue I/O directly via (/dev/sda1) interface? Does ceph prevent it, as such operations may corrupt data? Thanks in advance, naveen -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
