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seniorsassycat

Member

Registered: 2011-08-27

Posts: 76

Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

My netbook has a 60gb ssd with btrfs, is it a good idea to enable compression? My main goal for this net-book is battery life.
If i do enable compression only new files are compressed, is there a way to walk over old files and compress them?

My current partition looks like this:
/boot    ext2 200mb
/           btrfs 7g
/home  btrfs 46g

I need to make my root larger because i am running out of space so i'm going to be messing with the file systems anyway  this suggests that i place my entire system in a subvolume, is this something i can do retroactively, or would I have to do a reinstall, which i'm ok with

Last edited by seniorsassycat (2012-01-27 01:45:58)

schlehmil

Member

Registered: 2010-10-01

Posts: 19

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

I think you can online compress existing files with 'btrfs filesystem defragment -c [lzo,zlib] /'. Thus you do not have to create a new subvolume and copy every file. But I have not tried it yet myself.

seniorsassycat

Member

Registered: 2011-08-27

Posts: 76

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

The subvolume question should have been separate. What are the advantages of using subvolumes?

alphaniner

Member

From: Ancapistan

Registered: 2010-07-12

Posts: 2,810

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

My main goal for this net-book is battery life.

Everything else being equal, a compressed fs is going to increase power usage.

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seniorsassycat

Member

Registered: 2011-08-27

Posts: 76

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

Also running 'sudo btrfs file defrag -clzo /' returns imidiatly, should it be this quick? Does the file system need to be unmounted first? Will I need to be running off of a live cd to unmount root and home?

gee

Member

Registered: 2006-11-29

Posts: 313

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

For other people, like me, that wondered: that's because the command is not recursive, so you are only doing it on the directory / and nothing more.
As far as I understand not even the files in / will be touched.

DSpider

Member

From: Romania

Registered: 2009-08-23

Posts: 2,273

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

Compression can help with SDD longevity (less data written) but not the battery's longevity (which will require charging more often and eventually start to hold less charge). I would probably not enable compression at all. 60 GB is plenty.

If you think about it, while you can't actually replace either of them in a netbook, the battery is more important - at least in a portable device. Even if the SSD gives out in 5-8 years at least you could still boot from a USB stick and breathe some life into it. But replacing the battery... well, it's probably not gonna happen. And by that time it will probably end up on a garbage landfill anyway. Pff... Consumerism.

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jallenusn

Member

Registered: 2012-06-11

Posts: 34

Re: Should i use compression with btrfs, an ssd, and a 1.6 atom processor?

@gee:  Does this provide the same benefit as a drive/partition that had compression enabled from the start?