Date: Fri, 22 Jul 2016 21:44:18 +0300 From: Nikos Kastanas <zerotronic@gmail.com> To: Karl Denninger <karl@denninger.net>, freebsd-fs@freebsd.org Subject: RE: RE: ZFS, SSD and encryption Message-ID: <CAJPDrRvWPNe%2Bxj6DDiq_eXzEkEYQocNjp02297tGdJZPG-P2Fg@mail.gmail.com>
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>On 7/22/2016 07:48, Nikos Kastanas wrote: >> I have a Lenovo X220 laptop running FreeBSD 10.3-RELEASE with ZFS and > >encryption on a plain HDD. I am considering buying a Samsung Pro 850 SSD to > >boost performance but I am not sure if TRIM and ZFS+Encryption work well >> together. After some research online, I found *this page* > ><https://www.freebsd.org/doc/faq/all-about-zfs.html>which states the > >following: >> > >*Note: * > >ZFS TRIM may not work with all configurations, such as a ZFS filesystem on > >a GELI-backed device. >> > >From what I can understand from the above note, I should not use the > >encryption option when installing FreeBSD with ZFS on an SSD. TRIM will not > >work correctly and therefore the SSD performace will be impacted. >Meh. Simply not true. The reason for the "supported feature" flag here >is that this machine was recently rolled forward to 11.0-BETA1, but I >have not upgraded the pools yet from the feature set of 10.2. > >[karl@NewFS ~]$ zpool status zsr > pool: zsr >state: ONLINE >status: Some supported features are not enabled on the pool. The pool can > still be used, but some features are unavailable. >action: Enable all features using 'zpool upgrade'. Once this is done, > the pool may no longer be accessible by software that does not >support > the features. See zpool-features(7) for details. > scan: scrub repaired 0 in 0h6m with 0 errors on Sun Jul 17 03:12:01 2016 >config: > > NAME STATE READ WRITE CKSUM > zsr ONLINE 0 0 0 > mirror-0 ONLINE 0 0 0 > da8p4.eli ONLINE 0 0 0 > da9p4.eli ONLINE 0 0 0 > >errors: No known data errors > >[karl@NewFS ~]$ gpart show da8 >=> 34 468862061 da8 GPT (224G) > 34 2014 - free - (1.0M) > 2048 1024 1 freebsd-boot (512K) > 3072 1024 - free - (512K) > 4096 20971520 2 freebsd-zfs [bootme] (10G) > 20975616 134217728 3 freebsd-swap (64G) > 155193344 313667584 4 freebsd-zfs (150G) > 468860928 1167 - free - (584K) > >da8: <ATA INTEL SSDSC2BP24 0420> Fixed Direct Access SPC-4 SCSI device >da8: Serial Number BTJR41210025240AGN >da8: 600.000MB/s transfers >da8: Command Queueing enabled >da8: 228936MB (468862128 512 byte sectors) > > > >root@NewFS:/var/log # sysctl -a|grep trim >vfs.zfs.trim.max_interval: 1 >vfs.zfs.trim.timeout: 30 >vfs.zfs.trim.txg_delay: 32 >vfs.zfs.trim.enabled: 1 >vfs.zfs.vdev.trim_max_pending: 10000 >vfs.zfs.vdev.trim_max_active: 64 >vfs.zfs.vdev.trim_min_active: 1 >vfs.zfs.vdev.trim_on_init: 1 >kstat.zfs.misc.zio_trim.failed: 0 >kstat.zfs.misc.zio_trim.unsupported: 25748 >kstat.zfs.misc.zio_trim.success: 6120223 >kstat.zfs.misc.zio_trim.bytes: 295371051008 > > >And as you can see, TRIM is definitely working (on the devices that can >handle it); there are also spinning rust disks in this machine, thus the >"unsupported" reports as well. > >HOWEVER, I do suggest (strongly!) that you NOT use the particular SSD >you are intending to buy as it has no power-loss protection. Instead, >buy an Intel 730-series drive (that's what's in this machine); it has >that protection and it is *EXTREMELY IMPORTANT* as otherwise any power >event has the potential of silent corruption which is catastrophic -- >especially on an encrypted volume! > >That same machine has two other 730s running a Postgresql database (also >Geli-encrypted) and they're just fine in terms of their wear leveling >and such; the media "wearout" indicator shows that 95% of the device's >life remains and they currently have 10,000 power-on-hours. > >They'll wear out in something like another 20 years at present use >rates.... :) > >The 480MB version of that drive is currently available for roughly >$250. It is not the fastest SSD out there but the differences between >it and others are small and I have *verified* that the power-loss data >protection works on these units. IMHO they're the only "consumer" style >priced devices that I find acceptable for this reason; the S3500/S3700s >are good too, but a hell of a lot more money and unless you need the >write endurance IMHO not worth it. > >The 730 series hits the sweet spot in that it has power-loss protection >that *works* and yet they're reasonably priced. I own a bunch of them; >they're in my production servers under FreeBSD and also on my Win10 >desktop machine. > >-- >Karl Denninger >karl@denninger.net <mailto:karl@denninger.net <karl@denninger.net>> >/The Market Ticker/ >/[S/MIME encrypted email preferred]/ Thank you for your answer. So I guess the warning in the FAQ is probably outdated. I will seriously consider your suggestion considering the Intel SSD. Thank you for your help
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