SSD uncertainties

Hello

I am a long time opensuse user, that up to now, managed to find answers lurking in this forum and visiting opensuse:SDB, but on the following subject I seems to luck out. I can’t find any resent information regarding ssd:s, what is valid options in opensuse 12.1 and it’s new kernel?
I have implemented some things I found but I have a feeling it is somewhat old and redundant steps.

Here is a list that I would be happy if someone with insights in newer configuration options for <12.1> took a look at.

  1. fstab
/dev/disk/by-id/ata-OCZ-AGILITY3_OCZ-XU4E2Z2O01X6628H-part1 /                    ext4       acl,user_xattr        1 1
tmpfs                /tmp                 tmpfs      defaults              0 0 

I have not used the option because I read that it is a default, is it?
Should the read any different, perhaps or something?

  1. Kernel-settings, changed to - I figure that one still is valid?

  2. boot.local

hdparm -W1a0A0 /dev/sdc

echo noop > /sys/block/sdc/queue/scheduler

echo 1 > /sys/block/sdc/queue/iosched/fifo_batch

echo 500 > /proc/sys/vm/dirty_writeback_centisecs

echo 20 > /proc/sys/vm/dirty_ratio

echo 5 > /proc/sys/vm/dirty_background_ratio

Is all this still necessary? Have it ever been?

  1. Have cron running <fstrim> once a week. Is that needed this days?

Any insights into all this is much appreciated or at least links to up-to-date information.

Thanks

Here is an excerpt from my fstab file where I am using two 120 GB Corsair SSD drives:

/dev/disk/by-id/ata-Corsair_Performance3_SSD_1117810101000341020B-part4        /                ext4    acl,user_xattr,noatime,discard    0    1
/dev/disk/by-id/ata-Corsair_Performance3_SSD_111381000100034100BF-part1        /home        ext4    acl,user_xattr,noatime,discard    0    2

I recommend using an EXT4 partition and adding in the two options noatime & discard as my example above. I don’t recommend you mess with any other other files. It is possible to change Firefox to use the SSD for caching your web pages but really, it does speed up most all things without any other changes. It trimmed 12 % off of the time doing a Kernel compile for instance, but the most dramatic change is the very quick startup of your PC.

Thank You,

I recommend using an EXT4 partition and adding in the two options noatime & discard as my example above. I don’t recommend you mess with any other other files. It is possible to change Firefox to use the SSD for caching your web pages but really, it does speed up most all things without any other changes. It trimmed 12 % off of the time doing a Kernel compile for instance, but the most dramatic change is the very quick startup of your PC.

Thanks for your input, I will remove my extra options from boot.local, edit my fstab as suggested. I’m just concerned about wearing the disks out but have no facts saying they will. I must say that SSD:s are probably the greatest thing that happend to pc:s the last ten years.

So SSD’s have some sort of limited live span, but getting a hold of just what that means seems difficult for me. If you have had more than one mechanical hard drive fail, which I have, I am not sure that over the normal use of a SSD, if there will really be much difference in that failure rate over regular drives. Some fail, but most don’t over the live span you use a hard drive.

Thank You,

Ok, I have now added the “noatime,discard” options to my ssd:s entries in fstab.

I also made the “/tmp” and “/var/tmp” not to be written to disk, however - can that produce some, by me, unforeseen problems. I rebooted several times just to inspect if there be any anomaly but so far everything flies.

tmpfs                /tmp                 tmpfs      defaults,noatime              0 0 
tmpfs                /var/tmp             tmpfs      defaults,noatime              0 0 

I also made Firefox use RAM for it’s caching, that also prevents a lot of disk-writes.

I still wonder about the need of running “fstrim” at a regular basis, is that redundant now days?

Well the bottom line of these two parameters is you are swapping disk space for memory and while an SSD might be equal to memory, I don’t know you will see much difference and SHOULD NOT add “tmpfs /var/tmp” because some info left there is expected to still be there after a reboot. Using “tmpfs /tmp” can reduce main memory usage which is OK, but I would wonder if anything would really be faster? You would have to do something major that uses lots of /tmp space and time the action with and with adding it to your fstab file to see what difference it would make. Now making changes to Firefox can be useful with a SSD as in: Disable Firefox caching by setting browser.cache.disk.enable to false in about:config OR Alternatively create the entry browser.cache.disk.parent_directory and set it to /tmp if you kept the “tmpfs /tmp” entry in your fstab file. I am seeing a couple of setups for /tmp being recommended:

tmpfs   /tmp   tmpfs   nodev,nosuid,noexec,relatime,mode=1777,size=15%    0    0

or

tmpfs   /tmp   tmpfs   defaults,noatime,mode=1777 0    0

With the second more to your setup, but since I don’t use it, its hard to make a recommendation to you.

Thank You,

Tanks for your clarification and interest,

I removed the “tmpfs /var/tmp” line from fstab so it won’t create any problems later on.
Firefox caching I keep in ram since I seldom use more than 3GB of 12 installed.
I truly hate that blinking hdd led. :wink: