Dear all,

i have the following machine:

i3770k(no overclock), z77 based MB, 16GB sdram, primary hd:OCZ Vertex SSD
OS: Debian "stretch"

I am using this machine mainly for firmware/sw development, no gaming etc.

Issue:
1) happen sometime, after several time i compile a program in the same folder, compile operation start to become slow, at a point that become very slow, to give an idea, more than 5 times than normal good behavior.
If i copy the working folder in another HD location, (cp -a) things comes back quite normal.
2) after an apt-get update, apt-get updrade (jessie to stretch), so several files downloaded, installed, erased, etc, linux boot process become slow, about 2 time slower than normal.
3) Issue 1 and 2 generally don't resolve on a reboot.

Every help is really appreciated
Angelo

It's because of filesystem issue. Fragmentation plus filesystem directory management. For one you make a new directory each time for compilation and afterwards delete that one. For second if there is defrag program available, then run that.

Hi veerian,

no. As far as i know, linux ext4 works very different from FS where you need to defrag. In fact there is no defrag program becouse the file management is very different. I don't think it is a fs issue. I suspect an SSD issue.

Read this page on ext4.

what will df tell (how much free space do you have)?

Hi,

ok i viewed ext4 page, and seen there is anyway a defrag tool. I will try it.

$ df
File system 1K-blocchi Usati Disponib. Uso Montato su
/dev/dm-1 221001452 52416580 157335620 25% /
udev 10240 0 10240 0% /dev
tmpfs 3309804 9512 3300292 1% /run
tmpfs 8274508 0 8274508 0% /dev/shm
tmpfs 5120 4 5116 1% /run/lock
tmpfs 8274508 0 8274508 0% /sys/fs/cgroup
/dev/sda1 240972 36048 192483 16% /boot
tmpfs 1654904 4 1654900 1% /run/user/1000
/dev/sdh1 516040 8204 481624 2% /media/angelo/BOOT

About the SSD, i already have noatime on fstab, and done "fstrim /" already. No changes.

So your root filesystem has ample space. It uses only 25 of block device space. So the slowness problem is not due to low filesystem space.

Thanks for the help.

My suspect is about the SSD. Maybe this OCZ Vertex is not so robust. But i don't know how to prove this.

Some things spring to mind. The first is that SSDs don't "fragment" like spinny disks so I would steer clear of trying to defragment. The second is that if a disk is set to trim in fstab this can, apparently, slow down file operations so trim should be run manuallly or via a cron job. If the file system is not mounted with the noatime or relatime option it ought to be as the constant writes when file access time is written can, apparently, also cause issues.
Sorry am using my phone so can't provide links but a quick google regarding the above should yeild decent resulsts.