On Wed, Jul 18, 2018 at 08:06:10PM +0800, Ming Lei wrote: > IMO the problem isn't related with slow or quick device, it is related with > the system, especially when it cares about power consumption, such as > mobile phone, or laptop or servers with lots of disks attached. And we know > it is often to see some fast disks shipped in laptop, such as NVMe, or other > SSD. Yes but you're only taking locally attached devices into account. This is very likely harmful on sd devices attached to a SRP/FC/iSCSI/SAS Target in a SAN environment. These can be really fast and people investing this money are likely to not like additional performance penalties. Furthermore I'd don't know if any array vendors actually implement START/STOP DISK, etc.. -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
