https://bugzilla.kernel.org/show_bug.cgi?id=47151 Jeff Moyer <jmoyer@xxxxxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jmoyer@xxxxxxxxxx --- Comment #10 from Jeff Moyer <jmoyer@xxxxxxxxxx> 2012-10-05 18:07:33 --- (In reply to comment #8) > 8K is to be understood instead of the usual 4K as page size (smallest read- and > writeable entity). Internal to the device, it's the smallest I/O size. But the device continues to export probably a 512 byte logical block size (or, more rarely, a 4k one). > Eric: I doubt that anyone would file a bug report on it as > the only effect of using a wrong fs block size will be degraded performance and > a shortened lifetime of the SSD (nobody would in deed find out about it who > hasn`t tried it with 8KB block size or heard about disks with page size != 4K). Given that pretty much all file systems running on Linux and Windows will use a block size less than or equal to the page size (4k), you can bet that the SSD vendor took this into account when advertising both the performance of the drive and the lifetime. I'll also note that this SSD isn't posing any new problems. Consider RAID devices. They would also like I/O in larger than page size quantities. We don't have to provide that in order to get good performance, though, for a large number of reasons (which vary depending on the exact hardware and software configuration you're talking about). Also keep in mind that the workload you intend to run will play a large role when determining what file system block size you choose (for example, to avoid unnecessary wasting of space). > Feel free to care about it whenever you want as we do not have any users > requiring it yet (to me for myself this isn`t any issue since I don`t plan to > use the besaid disk at the time). If you want to play around with things, try creating a 4k file system with a stripe width of 2. Of course, you'd have to have the hardware to try this, and you don't, nor does anyone looking at this, so the discussion is moot. The bottom line is that if someone wants to take on the work to get file system block sizes pushed beyond page size, we're all for it. Lobbying for this to get done isn't going to help as much as doing the work or paying someone to do the work, though. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
