Feature changed by: Will Stephenson (wstephenson) Feature #311341, revision 7 Title: Yast Partitioning give SSD best practice option openSUSE Distribution: Unconfirmed Priority Requester: Desirable Info Provider: Hans de Raad (hcderaad) Requested by: Hans de Raad (hcderaad) Partner organization: openSUSE.org Description: More and more laptops, netbooks, pc's, servers, actually anything with some kind of storage need is equipped with Solid State Disks. Although at first glance they may seem quite similar to harddisks, they really are a completely different species with some very different characteristics. It might be convenient for having an "SSD Best practise enabler" switch when creating partitions on disks in Yast, which would then automatically setup the features (and possibly others) mentioned in the "Why do we want this" part of this feature. Use Case: During installation (or partition editing) when a user configures a partition, the option would be presented to enable SSD Best practises. Business case (Partner benefit): openSUSE.org: Especially in the partitioning stage of the installation process one can make or break the extra performance one might gain from using SSD's. Especially aligning a filesystem to SSD erase block size and enabling TRIM on partitions are really noticeable performance enhancers. Also, when the SSD option is activated, the Swap partition would be suggested to be removed from the partition setup (if one is set). Discussion: #1: Arvin Schnell (aschnell) (2011-02-23 03:36:05) Parted (used by the YaST partitioner) already respects the alignment information provided by disks. Not having a swap partition disallowes suspend to disk, an essential feature on mobile devices. What detailed actions should be taken concerning the TRIM command? #2: Hans de Raad (hcderaad) (2011-02-23 13:07:59) (reply to #1) Concerning TRIM there already is some detailed info on the wiki: http://en.opensuse.org/SDB:SSD_discard_%28trim%29_support The swap option might be a bit farfetched but netbooks like the Acer Aspire One discouraged the use of swapping because of the lifetime of the ssd (will look for citation). I didnt know about the alignment in Yast, but the biggest benefit should be gained from automatically mount SSD partitions with TRIM enabled. (ie https://sites.google.com/site/lightrush/random-1/howtoconfigureext4toenablet... ) Does this answer your quetion sufficiently? Regards and thanks for your answer, HdR #3: Arvin Schnell (aschnell) (2011-02-23 14:49:21) (reply to #2) Yes, but the kernel/tools don't look mature yet. #4: Hans de Raad (hcderaad) (2011-02-25 11:55:53) (reply to #3) Again thanks for responding. I dont have enough specific kernel/ext4 knowledge comment on the maturity of the tools, this function seems to be in testing phase in the kernel (http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.36 look for ext4). The wiper.sh script does make a difference for my system with an OCZ Vertex II (i dont have hard benchmarks but the overall responsiveness is definitely better after a monthly wipe). Perhaps we can offer the option at the moment its considered stable in a future release? + #5: Will Stephenson (wstephenson) (2011-02-28 16:31:04) (reply to #1) + TRIM: we can mount ext4 with the discard option, then the filesystem + TRIMs deleted files. James Bottomley says in #suse that this is + probably the worst performing way to do this, but is it still better + than no TRIM at all on a default install? + Swap: the sensitivity to write bandwidth seems to improve for newer + generations of SSDs; perhaps it is no longer critical to avoid using + swap on SSD. Some recommend tuning kernel swappiness parameters - taken + to an extreme a swap partition would only be used for s2disk. Others + recommend putting /tmp on a tmpfs, and /var/ and even /home on spinning + disks instead of the SSD. + The steps I took on my recent SSD install were: + * mount ext4 with noatime,discard so deleted files are TRIMmed and + returned to free space + * align partitions to erase block boundaries (not sure if this has any + effect as long as things are not writing to the last/first sectors that + might otherwise span erase blocks) + * use elevator=noop for the SSD as cfq is said to be counterproductive + * swap on a spinning disk -- openSUSE Feature: https://features.opensuse.org/311341