Craig Sanders via luv-main <luv-main@luv.asn.au> writes:
On Wed, Jan 13, 2016 at 01:28:57PM +1100, Trent W. Buck wrote:
AFAICT the only reason SSHDs exist are:
* Windows has nothing like bcache/l2arc; or
it does. it's called ReadyBoost. Compared to bcache/flashcache or L2ARC for ZFS, it sucks. You can't just tell Windows to use an SSD (or partition thereof) to cache an arbitrary disk....well, in theory you
That sounds like the one they introduced back when USB keys were cool. I don't think anyone seriously intends it for hybrid SSD/HDD usage. "the maximum cache size per device is 4GB (Vista) or 32GB (Windows 7)."
can but in practice Windows itself decides whether that option will be available by its own inscrutable and undocumented method.
It looks like the drive has to NTFS/exFAT/FAT formatted, because ReadyBoost caches to a file, not a disk/partition.
I discovered this just last week after upgrading my win7 games box to have an SSD as a boot disk, decided to try ReadyBoost for my main 2TB steam library drive (not an SSHD) so made a 40GB partition for it. No matter what I tried, I couldn't get windows to make the option available in its Disk Manager GUI - it was there, just greyed out.
See above re 32GB cap. (Aside: the windows types I've asked about this indicate that they actually use the hardware vendor's hybrid drive implementation, e.g. Intel's.)
I gave up and expanded the main partition...will have to manually move big games to the fast SSD, which works nicely - witcher 3 loads much faster off the SSD. More importantly, save games load in about 25 seconds rather than 60-90 seconds (which is really annoying when you die repeatedly because you thought attacking a royal griffin seemed like a good idea, 90 seconds to load the save, 15 seconds to die again while trying to run away, repeat until you succeed or rage-quit)
I know at least one guy who netboots his Windows games machine off a linux array, exported as iSCSI or something. I dunno where the bottleneck is there, but it means he can snapshot the disk &c like it was a VM.
* My computer only has one disk bay.
(you don't really need a disk bay for an SSD. just a sata port plus data and power cables. and if you wanna get fancy you can sticky-tape it to the side of the case :)
I was handwaving that detail away; I was specifically thinking of laptops with a single 2.5" bay and no M.2.
but given that the SSHDs i bought were roughly the same price as non-SSHDs
Hrm... $ msy | foldr grep -Fi -- 2tb 3.5 sata3 7200 135 Seagate 3.5" SSHD 2TB ST2000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 98 Seagate 3.5" Barracuda 2TB ST2000DM001 SATA3 7200rpm 64MB Cache Hard Disk $ msy | foldr grep -Fi -- 4tb 3.5 sata3 5400 249 WD 3.5" SSHD WD40E31X 4TB 5400RPM SATA3 Hybrid (8G SSDHDD) NAND SSHD 202 WD 3.5" Blue 4TB WD40EZRZ 64M 5400RPM SATA3 HDD $ msy | foldr grep -Fi -- 4tb 3.5 sata3 5900 329 Seagate 3.5" Enterprise NAS 4TB ST4000VN0001 SATA3 5900rpm 64MB Cache HDD 275 Seagate 3.5" SV35 ST4000VX002 4TB 5900rpm Surveillance HDD include Data Rescue Service 259 Seagate 3.5" NAS 4TB ST4000VN003 SATA3 5900rpm 64MB Cache HDD include Data Rescue Service 239 Seagate 3.5" SV35 ST4000VX000 4TB 5900rpm Surveillance HDD 219 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 5900rpm 64MB Hybrid HDD 219 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 185 Seagate 3.5" Barracuda 4TB ST4000DM000 SATA3 5900RPM 64MB Cache Hard Disk That's a ~20% markup on the first two. SSDs start at A$60 for 120GB -- not much more than the difference.
, i don't see any harm and some potential benefit in using them on linux. 8GB cache isn't much but it "just works" without any hassle or configuration. it's giving me some SSD caching on my ZFS 'backup' pool without having to add another SSD to the same andr dedicate an SSD partition to the task.
I guess that's reasonable. What's the failure mode when the NAND wears out? Does it detect that and fall back to being a regular HDD?
On Thu, 14 Jan 2016, Trent W. Buck via luv-main wrote:
$ msy | foldr grep -Fi -- 2tb 3.5 sata3 7200
msy? That looks nifty, given how horrible browsing the pictures on their webshite is. details?
What's the failure mode when the NAND wears out? Does it detect that and fall back to being a regular HDD?
Hah! You did a funny. Hardware venduhs having sane error handling. But even if it did fall back, it would become unusable. 200mb write stripes. Gives you about 1 IOP when writing random seeks. -- Tim Connors
On Fri, Jan 15, 2016 at 12:54:42AM +1100, Tim Connors wrote:
On Thu, 14 Jan 2016, Trent W. Buck via luv-main wrote:
$ msy | foldr grep -Fi -- 2tb 3.5 sata3 7200
msy? That looks nifty, given how horrible browsing the pictures on their webshite is.
details?
try my msygrep script. http://taz.net.au/~cas/msytools/
But even if it did fall back, it would become unusable. 200mb write stripes. Gives you about 1 IOP when writing random seeks.
the 200MB stripes are on the Archive drives, not the SSHDs. The SSHDs are normal drives with an 8GB flash cache in addition to the usual 64MB RAM cache. craig -- craig sanders <cas@taz.net.au>
On 15/01/16 08:46, Craig Sanders via luv-main wrote:
try my msygrep script.
Very handy! Unfortunately fetch-MSY.sh uses bashisms but only calls for /bin/sh which isn't necessarily /bin/bash - including on my machine. Thanks, Andrew
Andrew Pam via luv-main <luv-main@luv.asn.au> writes:
On 15/01/16 08:46, Craig Sanders via luv-main wrote:
try my msygrep script.
Very handy! Unfortunately fetch-MSY.sh uses bashisms but only calls for /bin/sh which isn't necessarily /bin/bash - including on my machine.
cas may be interested in these: devscripts: /usr/bin/checkbashisms shellcheck: /usr/bin/shellcheck The former is a Debianism; the latter is Haskell. They're not great, but they're better than nothing.
On 15/01/16 08:46, Craig Sanders via luv-main wrote:
try my msygrep script. http://taz.net.au/~cas/msytools/
Where do I find untable.pl ? Thanks, Andrew
On Fri, Jan 15, 2016 at 10:19:57AM +1100, Andrew Pam wrote:
On 15/01/16 08:46, Craig Sanders via luv-main wrote:
try my msygrep script. http://taz.net.au/~cas/msytools/
Unfortunately fetch-MSY.sh uses bashisms but only calls for /bin/sh which isn't necessarily /bin/bash - including on my machine.
fixed.
Where do I find untable.pl ?
sorry, i forgot fetch-MSY.sh needed that. it's in the same web directory now. craig -- craig sanders <cas@taz.net.au>
Tim Connors wrote:
On Thu, 14 Jan 2016, Trent W. Buck via luv-main wrote:
$ msy | foldr grep -Fi -- 2tb 3.5 sata3 7200
msy? That looks nifty, given how horrible browsing the pictures on their webshite is.
details?
http://www.cyber.com.au/~twb/.bin/msy http://www.cyber.com.au/~twb/.bin/foldr Not using XSLT I'm afraid. I don't really *buy* from MSY anymore, but I use that as a lowball quote comparison. There's staticice, but I suck at driving clicky browsers.
What's the failure mode when the NAND wears out? Does it detect that and fall back to being a regular HDD?
Hah! You did a funny. Hardware venduhs having sane error handling.
But even if it did fall back, it would become unusable. 200mb write stripes. Gives you about 1 IOP when writing random seeks.
I guess I really meant "usable long enough to get the data off it". Since this is mostly being talked abuot in the context of dinky gaming machines & laptops, rather than 4U servers, I figure the person buying probably hasn't bothered to set up a proper backup/archive regime.
"Trent W. Buck via luv-main" writes:
Tim Connors wrote:
msy? That looks nifty
http://www.cyber.com.au/~twb/.bin/msy http://www.cyber.com.au/~twb/.bin/foldr
Not using XSLT I'm afraid.
Ta-daaaaaaa! I was angry enough at my script that I rewrote it. Now it uses XSLT instead of a browser.
On Thu, Jan 14, 2016 at 04:51:42PM +1100, Trent W. Buck wrote:
it does. it's called ReadyBoost.
That sounds like the one they introduced back when USB keys were cool.
yeah, it was originally intended to be used with very fast (for the time) USB flash disks. there was even a short-lived product category of 4 and 8GB "Ready Boost capable" flash disks...many designed to plug straight into a motherboard USB jumper block rather than an external USB port (or into both via a tiny jumper block -> USB port adaptor)
I don't think anyone seriously intends it for hybrid SSD/HDD usage.
yeah. that could be because if you search the windows forums, all you see is morons talking about how it's some kind of virtual memory thingy. they obviously don't have a clue what they're talking about, but the mythology that ReadyBoost is some kind of super-fancy virtual memory is pervasive. multiple layers of caching (SSD and RAM) is obviously too difficult a concept for the average windows users to grasp....but there's no reason why RB on a fast SSD couldn't provide the same kind of read benefits that L2ARC provides for ZFS.
It looks like the drive has to NTFS/exFAT/FAT formatted, because ReadyBoost caches to a file, not a disk/partition.
the option was greyed out whether i tried to give it a formatted or unformatted partition.
See above re 32GB cap.
as you said, it uses a file on an NTFS or exFAT (works on FAT too but is limited by FAT's 4GB filesize limit) partition, so the size of the partition doesn't matter, only the size of the RB file. i also tried it with a 20GB partition so if they partition size was relevant, that should have worked.
(Aside: the windows types I've asked about this indicate that they actually use the hardware vendor's hybrid drive implementation, e.g. Intel's.)
yeah. i just *love* vendor-specific software. i'm really keen to tie myself to specific cpu and/or disk vendor brands. i don't have any intel machines or motherboards. every time i think i should get one of the nice new intel cpus, i'm put off by the fact that the M/B + CPU cost almost double what a roughly equivalent AMD system would cost and for anything faster you're paying a lot more again. worse, they have half the SATA ports and PCI-e lanes (admittedly they're pci-e 3.0 rather than pci-e 2.0, but i have exactly one PCI-e card that can make use of 3.0, and it really makes little practical difference in real life whether it's in a 2.0 slot or 3.0. recentish AMD m/bs like the Asus Sabertooth 990FX rev. 2 support PCI-e 3.0, but they're won't be an AMD CPU supports it until Zen is released late this year). the number of sata ports is important to me because i currently have 10 sata 3 drives installed in my main combined workstation/server box and spare hot-swap bays for 4 more for future expansion/upgrades (being able to replace the drives in my zfs pools without having to remove the old ones first is useful). some of those drives are on an LSI SAS2008 8-port SAS card.
I know at least one guy who netboots his Windows games machine off a linux array, exported as iSCSI or something. I dunno where the bottleneck is there, but it means he can snapshot the disk &c like it was a VM.
i thought about doing similar using iscsi exports from my zfs pool. decided not to bother because it's hard to see how a 1Gbps network disk can be remotely close in performace to a local 6Gbps SATA SSD (good SATA SSDs get up to 550MB/s read and 400+ write). M.2 / PCI-e SSDs can be (and are) a LOT faster than that. 1Gbps isn't too bad compare to a mechanical hard disk.
$ msy | foldr grep -Fi -- 2tb 3.5 sata3 7200
BTW did i ever give you a copy of my msygrep script? it does what you 'msy | foldr grep ...' does and a bunch more stuff (including grep -v style AND min/max price exclusions, and the ability to fetch the latest parts list. also to optionally search through archived price lists for price comparisons over time). http://taz.net.au/~cas/msytools/ i remember talking about it with you some time ago...and my fetch-MSY.sh script has a copy of your code to strip MS Word crap from the text file. NOTE to anyone who dowloads these scripts, remember to change the MSYDIR variable NEAR the start of the script to something valid, like "~/MSY" or "~/dl/MSY" e.g. even with the exchange rate going to crap, the ST4000DX001 has gone down $23 since it first appeared on MSY's price list in May 2014. $ msygrep -a ST4000DX001 | uniq -f1 2014-05-01 242 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2014-11-01 239 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2014-12-18 233 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2015-01-10 225 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2015-02-16 235 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2015-04-18 229 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2015-06-25 228 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 7200rpm 64MB Hybrid HDD 2015-08-21 228 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 5900rpm 64MB Hybrid HDD 2015-12-03 225 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 5900rpm 64MB Hybrid HDD 2015-12-29 219 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 5900rpm 64MB Hybrid HDD Current 219 Seagate 3.5" SSHD 4TB ST4000DX001 NAND 8GB SATA3 5900rpm 64MB Hybrid HDD The ST4000VN000 has dropped $40 from 259 to 219 since Aug 2013, but only $10 since May 2014 when the 4TB SSHD appeared. $ msygrep -a ST4000VN000 -v Enterprise | uniq -f1 2013-08-27 259 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2013-09-05 242 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2013-09-11 241 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2013-12-02 230 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2014-02-15 239 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2014-05-01 229 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2014-07-06 227 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2014-11-01 215 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2014-11-21 214 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2015-03-03 225 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2015-04-24 228 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2015-05-13 225 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2015-08-21 224 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2015-12-03 223 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD 2015-12-29 219 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD Current 219 Seagate 3.5" NAS 4TB ST4000VN000 SATA3 5900rpm 64MB Cache HDD interestingly, hard disk prices have hardly moved much in years....while SSD prices are dropping rapidly (and sizes and speeds are also improving).
That's a ~20% markup on the first two. SSDs start at A$60 for 120GB -- not much more than the difference.
mine are Seagate ST4000DX001. same price as the ST4000VN000 NAS model...which is what i'd use in a RAID or ZFS or btrfs array because they don't have firmware that's crippled for use in "NAS" type setups (specifically long timeouts and retries on errors....reasonable for dekstop usage but tends to get drives booted out of raid etc arrays because it seems like a failing disk). Either that WD Red WD40EFRX or the Hitachi HGST 0S03666
What's the failure mode when the NAND wears out? Does it detect that and fall back to being a regular HDD?
no idea and i hope so. craig -- craig sanders <cas@taz.net.au>
participants (5)
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Andrew Pam -
Craig Sanders -
Tim Connors -
Trent W. Buck -
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