Re: btrfs-image hash collision option, super slow

2017-11-11 Thread Chris Murphy
On Sat, Nov 11, 2017 at 5:42 PM, Hugo Mills wrote: > On Sat, Nov 11, 2017 at 05:18:33PM -0700, Chris Murphy wrote: >> OK this might be in the stupid questions category, but I'm not >> understanding the purpose of computing hash collisions with -ss. Or >> more correctly, why

Re: btrfs-image hash collision option, super slow

2017-11-11 Thread Hugo Mills
On Sat, Nov 11, 2017 at 05:18:33PM -0700, Chris Murphy wrote: > OK this might be in the stupid questions category, but I'm not > understanding the purpose of computing hash collisions with -ss. Or > more correctly, why it's taking so much longer than -s. > > It seems like what we'd want is every

Re: discard on SSDs quickly causes backup trees to vanish

2017-11-11 Thread Qu Wenruo
On 2017年11月12日 04:12, Hans van Kranenburg wrote: > Hi, > > On 11/11/2017 04:48 AM, Qu Wenruo wrote: >> >> On 2017年11月11日 11:13, Hans van Kranenburg wrote: >>> On 11/11/2017 03:30 AM, Qu Wenruo wrote: >>> One more chance to recover is never a bad idea. >>> >>> It is a bad idea. The

btrfs-image hash collision option, super slow

2017-11-11 Thread Chris Murphy
OK this might be in the stupid questions category, but I'm not understanding the purpose of computing hash collisions with -ss. Or more correctly, why it's taking so much longer than -s. It seems like what we'd want is every filename to have the same hash, but for the file to go through a PBKDF

Re: discard on SSDs quickly causes backup trees to vanish

2017-11-11 Thread Hans van Kranenburg
Hi, On 11/11/2017 04:48 AM, Qu Wenruo wrote: > > On 2017年11月11日 11:13, Hans van Kranenburg wrote: >> On 11/11/2017 03:30 AM, Qu Wenruo wrote: >>> >> >>> One more chance to recover is never a bad idea. >> >> It is a bad idea. The *only* case you can recover from is when you >> freeze the

Re: btrfs send yields "ERROR: send ioctl failed with -5: Input/output error"

2017-11-11 Thread Chris Murphy
On Sat, Nov 11, 2017 at 11:27 AM, Zak Kohler wrote: > It seems that since the errors were due to a very slight instability in > computer due to overclock, the online and offline scrub's causing different > stresses or paths. Could it be that one is telling the drives to use