On 1/28/21 9:12 AM, Sergei Shtepa wrote:
I`m ready to suggest the blk_interposer again. blk_interposer allows to intercept bio requests, remap bio to another devices or add new bios. This version has support from device mapper. For the dm-linear device creation command, the `noexcl` parameter has been added, which allows to open block devices without FMODE_EXCL mode. It allows to create dm-linear device on a block device with an already mounted file system. The new ioctl DM_DEV_REMAP allows to enable and disable bio interception. Thus, it is possible to add the dm-device to the block layer stack without reconfiguring and rebooting.
What functionality does this driver provide that is not yet available in a RAID level 1 (mirroring) driver + a custom dm driver? My understanding is that there are already two RAID level 1 drivers in the kernel tree and that both driver support sending bio's to two different block devices.
Thanks, Bart.
