Is there a performance advantage in using Btrfs subvolumes over raw (MBR/GPT) partitions on rotational disks?

2016-08-28 Thread Alexander Tomokhov
Let's say I use a 128GiB MBR partition for OS and remaining 800GiB+ on disk serves another purpose. Then all OS files will be physically close to each other on the disk, thus reducing seek times. If I use the whole disk for OS partition, then files will be spread across the disk and even OS-only

Does data checksumming remain for files with No_COW file attribute?

2016-09-24 Thread Alexander Tomokhov
There is an unanswered question at stackexchange: http://unix.stackexchange.com/q/303130/41572 Assume that we don't invoke mount options like nodatacow and nodatasum - operate only at file attributes level, which are controlled with lsattr/chattr. So does setting No_COW on a file (chattr +C) imp

Re: Does data checksumming remain for files with No_COW file attribute?

2016-09-24 Thread Alexander Tomokhov
file. 24.09.2016, 15:37, "Hugo Mills" : > On Sat, Sep 24, 2016 at 03:26:14PM +0300, Alexander Tomokhov wrote: >>  There is an unanswered question at stackexchange: >>  http://unix.stackexchange.com/q/303130/41572 >> >>  Assume that we don't invoke mount options lik

Is it possible to have metadata-only device with no data?

2017-02-05 Thread Alexander Tomokhov
Is it possible, having two drives to do raid1 for metadata but keep data on a single drive only? -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

Re: Is it possible to have metadata-only device with no data?

2017-02-13 Thread Alexander Tomokhov
017 22:55:42 +0100 > Hans van Kranenburg wrote: > >>  On 02/05/2017 10:42 PM, Alexander Tomokhov wrote: >>  > Is it possible, having two drives to do raid1 for metadata but keep data >> on a single drive only? >> >>  Nope. >> >>  Would be a really ni

Re: Is it possible to have metadata-only device with no data?

2017-02-13 Thread Alexander Tomokhov
Yeah, thank you for suggestion. Bcache is what I actually use right now. However it's concept is different, operating at block/bucket level and requires another (underlying!) layer. 06.02.2017, 01:27, "Kai Krakow" : > Am Mon, 06 Feb 2017 00:42:01 +0300 > schrieb Alexander T