similar to: TRIM discard testing

I''ve got two recent examples of SSDs. Their pristine state from the manufacturer shows: Device Model: OCZ-VERTEX3 # hexdump -C /dev/sdd 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 1bf2976000 Device Model: OCZ VERTEX PLUS (OCZ VERTEX 2E) # hexdump -C /dev/sdd 00000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................| *

For using SSDs: Are there any format/mount parameters that should be set for using btrfs on SSDs (other than the "ssd" mount option)? General questions: How long is the ''delay'' for the delayed alloc? Are file allocations aligned to 4kiB boundaries, or larger? What byte value is used to pad unused space? (Aside: For some, the erased state reads all 0x00, and for

Hi! With 3.2-rc4 (probably earlier), Ext4 seems to remember what areas it trimmed: merkaba:~> fstrim -v /boot /boot: 224657408 bytes were trimmed merkaba:~> fstrim -v /boot /boot: 0 bytes were trimmed But BTRFS does not: merkaba:~> fstrim -v / /: 4431613952 bytes were trimmed merkaba:~> fstrim -v / /: 4341846016 bytes were trimmed Is it planned to add this feature to BTRFS

I'm trying to work out the kinks of a proprietary, old, and clunky application that runs on CentOS. One of its main problems is that it writes image sequences extremely non-linearly and in several passes, using many CPUs, so the sequences get very fragmented. The obvious solution to this seems to be to use SSDs for its output, and some scripts that will pick up and copy our the sequences

Hi, One question please: If I use SSD as a storage on a host machine, does KVM's virtio I/O layer pass the TRIM/DISCARD commands to the SSD? I guess the question would be twofold: 1) is TRIM supported/forwarded if only one LVM'ed partition of SSD is forwarded? 2) is TRIM supported/forwarded if full SSD is forwarded (i.e. /dev/sdX) -- Best regards, Dmitry Mikhailov

Hi, After reading through the btrfs documentation I''m curious to know if it''s possible to ever securely erase a file from a btrfs filesystem (or ZFS for that matter). On non-COW filesystems atop regular HDDs one can simply overwrite the file with zeros or random data using dd or some other tool and rest assured that the blocks which contained the sensitive information have

I''m looking to try BTRFS on a SSD, and I would like to know what SSD optimizations it applies. Is there a comprehensive list of what ssd mount option does? How are the blocks and metadata arranged? Are there options available comparable to ext2/ext3 to help reduce wear and improve performance? Specifically, on ext2 (journal means more writes, so I don''t use ext3 on SSDs,

On Mon, Feb 8, 2016 at 3:18 PM, <m.roth at 5-cent.us> wrote: > Chris Murphy wrote: >> DBAN is obsolete. NIST 800-88 for some time now says to use secure erase >> or enhanced security erase or crypto erase if supported. >> >> Other options do not erase data in remapped sectors. > > dban doesn't? What F/OSS does "secure erase"? And does it do

I am planning on using solid state disks with my CentOS 5.x systems. Currently, I am using EXT3 for the file system. >From what I can find, CentOS 5.x does not support TRIM on solid state disks? Is this correct? Should I obtain and build the updated hdparm and use that to trim my drives (for example, via CRON every night at midnight)? Or should I get fstrim (updated util-linux)? Any other

I''ve just finished installing onto an OCZ Agilent v2 SSD with btrfs as filesystem. However to my surprise I''ve hit an ENOSPC condition one one of the partitions within less than a day of uptime, while the filesystem on that partition only reported 50% to be in use, which is far from the 75% limit people mention on the ML. Note that this occurs using a vanilla 2.6.32-rc5 kernel

On Fri 07 January 2011 08:14:17 Hubert Kario wrote: > I''d suggest at least > mkfs.btrfs -m raid1 -d raid0 /dev/sdc /dev/sdd > if you really want raid0 I don''t fully understand -m or -d. Why would this make a truer raid0 that with no options? Is it necessary to use fdisk on new drives in creating a BTRFS multi-drive array? Or is this all that''s needed: #

My google-fu is coming up short on this one... I didn''t see that it had been discussed in a while ... What is the status of ZFS support for TRIM? For the pool in general... and... Specifically for the slog and/or cache??? -------------- next part -------------- An HTML attachment was scrubbed... URL:

Dear all, While going through the archived mailing list and crawling along the wiki I didn''t find any clues if there would be any optimizations in Btrfs to make efficient use of functions and features that today exist on enterprise class storage arrays. One exception to that was the ssd option which I think can make a improvement on read and write IO''s however when attached to

Hi all, are there any plans that future versions of mkfs.btrfs will do an initial pre-discard for SSDs? (AFAIK mkfs.btrfs does not do this currently) For Ext4, mke2fs does this with the -E discard option. From the mke2fs manpage: -E discard Attempt to discard blocks at mkfs time (discarding blocks initially is useful on solid state devices and sparse / thin-provisioned storage). When

Currently, some new storage devices have the ability to do performance optimizations according to the type of data payload - say, file system metadata, time-stamps, sequential write in some granularity, random write and so on. For example, the latest eMMC 4.5 device can support the so-called ''Context Management'' and ''Data Tag Mechanism'' features. By receiving

The biggest one is a fix for fstrim, and there''s a fix for on-disk free space cache. Others are small fixes and cleanups. The last three have been sent weeks ago. The patchset is also available in this repo: git://repo.or.cz/linux-btrfs-devel.git for-chris Note there''s a small confict with Al Viro''s vfs changes. Li Zefan (11): Btrfs: add pinned extents to

I have a 24 x 1TB system being used as an NFS file server. Seagate SAS disks connected via an LSI 9211-8i SAS controller, disk layout 2 x 11 disk RAIDZ2 + 2 spares. I am using 2 x DDR Drive X1s as the ZIL. When we write anything to it, the writes are always very bursty like this: ool 488K 20.0T 0 0 0 0 xpool 488K 20.0T 0 0 0 0 xpool

(I see this in both R-patched r43124 and R-devel r43233.) In the Argument section of ?mean: trim the fraction (0 to 0.5) of observations to be trimmed from each end of x before the mean is computed. Values outside that range are taken as the nearest endpoint. Then in the Value section: If trim is non-zero, a symmetrically trimmed mean is computed with a fraction of trim observations

Hi, I''ve ordered a new server with: - 4x600GB Toshiba 10K SAS2 Disks - 2x100GB OCZ DENEVA 2R SYNC eMLC SATA (no expander so I hope no SAS/ SATA problems). Specs: http://www.oczenterprise.com/ssd-products/deneva-2-r-sata-6g-2.5-emlc.html I want to use the 2 OCZ SSDs as mirrored intent log devices, but as the intent log needs quite a small amount of the disks (10GB?), I was wondering

Same as its brothers/sisters, it's optimized for 4 KB blocks. /* * OCZ Vertex 4 SSDs * 4k optimized */ { T_DIRECT, SIP_MEDIA_FIXED, "ATA", "OCZ_VERTEX4*", "*"}, /*quirks/DA_Q_4K Borja.