334 reputation
27
bio website
location Finland
age 36
visits member for 2 years, 5 months
seen Nov 4 at 11:09

My daily work is a closed source PHP project but I'm really interested in open source projects and I know PHP, C/C++ and Perl 5 pretty well. I can do some Java, Python, x86 assembler (intel syntax) and some other programming languages, too. I'm currently running Ubuntu (workstation, home computer, laptop) and Cyanogenmod (phone) as my OS of choice. GPG: 563168EB


Sep
30
awarded  Commentator
Sep
30
comment Can I configure my Linux system for more aggressive file system caching?
Setting vfs_cache_pressure too high (I would consider 2000 too high) will cause unnecessary disk access even for simple stuff such as directory listings which should easily fit in cache. How much RAM do you have and what are you doing with the system? As I wrote in my answer, using high value for this setting makes sense for e.g. HD video editing with limited RAM.
Sep
24
awarded  Autobiographer
Sep
18
awarded  Nice Answer
Sep
1
answered Given a kernel ATA exception, how to determine which physical disk is affected?
Apr
11
revised Poor random read SSD performance on Linux
add missing notes about SATA+AHCI+NCQ and queue_depth
Apr
11
answered Poor random read SSD performance on Linux
Apr
11
comment Can I configure my Linux system for more aggressive file system caching?
One way to improve performance a lot is to skip durability of data. Simply disable syncing to disk even if some apps requests for sync. This will cause data loss if your storage device ever suffers loss of electricity. If you want to do it anyway, simply execute sudo mount -o ro,nobarrier /path/to/mountpoint or adjust /etc/fstab to include nobarrier for any filesystem that you're willing to sacrifice for improved performance. However, if your storage device has internal battery such as Intel 320 SSD series, using nobarrier causes no data loss.
Mar
18
awarded  Citizen Patrol
Jan
3
revised Can I configure my Linux system for more aggressive file system caching?
Provide a couple of example where tuning vfs_cache_pressure makes sense, warn about unsafe config despite the fact that this config matches the original question
Oct
22
awarded  Necromancer
Aug
30
awarded  Yearling
Aug
15
comment Can I configure my Linux system for more aggressive file system caching?
@rep_movsd I've been using only intel SSD drives but at least these drives are still slow enough to have better overall performance with more intelligent schedulers such as CFQ. I'd guess that if your SSD drive can deal with more than 100K random IOPS, using noop or deadline would make sense even with fast CPU. With "fast CPU" I mean something that has at least multiple 3GHz cores available for IO only.
Jan
28
comment Can I configure my Linux system for more aggressive file system caching?
@Phpdevpad: In addition, the question said "I am neither concerned about RAM usage [...]"--I don't think any Maemo device qualifies.
Oct
12
revised How to get better desktop performance in linux?
fix typo that reverses the logic in a sentence
Oct
12
comment How to get better desktop performance in linux?
I don't know about CentOS but at least with recent Ubuntu versions (12.04+), ulatencyd is available in the official repositories.
Oct
12
comment How can I zoom/magnify Cinnamon desktop using the mouse wheel?
I guess you have to compile the software from the source. Something like this should work: git clone git://github.com/tobiasquinn/gnome-shell-mousewheel-zoom.git; cd gnome-shell-mousewheel-zoom; debuild. See the messages and install missing build dependencies to get it to build. When you're done .deb packages should appear one directory above your current directory.
Oct
12
answered How can I zoom/magnify Cinnamon desktop using the mouse wheel?
Jun
29
awarded  Teacher
Jun
29
comment What's faster, dd 1.5TB or rsync 500GB?
I agree that rsync will be faster if the disk is readable. If there's any change that the disk is partially unreadable and you have no backup of the contained data, I'd rather run ddrescue to make as exact image of the disk as possible. After that, I'd make another copy of the "exact copy", run fsck on that and only then mount it. This way the "exact copy" of your failing disk is kept unmodified for additional rescue operations.