[gentoo-user] how to use my SSD the right way ;-)

[gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

I am running both my desktop and laptop on SSDs for years now.

I think I got the basic things right:

proper alignment of partitions, scheduler, TRIM (fstrim) ... you know.

Today I received my new and shiny Samsung 840 EVO and migrated my
desktop to it (writing this very email running Gentoo on it).

I use ext4 for / and /home ... with "noatime", yes.

I wonder if I should test another filesystem for /home or even / ...
maybe XFS? The system is snappy and works fine, I just wonder if another
fs would perform better with SSDs ?

Any opinions?

Greets, Stefan

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 03/01/2014 00:14, Stefan G. Weichinger wrote:
> 
> I am running both my desktop and laptop on SSDs for years now.
> 
> I think I got the basic things right:
> 
> proper alignment of partitions, scheduler, TRIM (fstrim) ... you know.
> 
> Today I received my new and shiny Samsung 840 EVO and migrated my
> desktop to it (writing this very email running Gentoo on it).
> 
> I use ext4 for / and /home ... with "noatime", yes.
> 
> I wonder if I should test another filesystem for /home or even / ...
> maybe XFS? The system is snappy and works fine, I just wonder if another
> fs would perform better with SSDs ?
> 
> Any opinions?
> 
> Greets, Stefan
> 
> 
> 


Before you test other fs's, do you use BFQ? What IO scheduler do you use?


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 02.01.2014 23:17, schrieb Alan McKinnon:

> Before you test other fs's, do you use BFQ? What IO scheduler do you use?

for SSD(s): noop
for HDD(s): cfq

both triggered/set via udev-rules

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 03/01/2014 00:23, Stefan G. Weichinger wrote:
> Am 02.01.2014 23:17, schrieb Alan McKinnon:
> 
>> Before you test other fs's, do you use BFQ? What IO scheduler do you use?
> 
> for SSD(s): noop
> for HDD(s): cfq
> 
> both triggered/set via udev-rules
> 
> 
> 
> 
> 


Give BFQ a try, set USE=experimental in *-sources to patch the source

euses -sf experimental giove further info and links



-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 02.01.2014 23:39, schrieb Alan McKinnon:

> Give BFQ a try, set USE=experimental in *-sources to patch the source
> 
> euses -sf experimental giove further info and links

thanks for the hint ...

edited USE-flags and re-emerging sources ...

BFQ only for the SSDs ?

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 03/01/2014 00:46, Stefan G. Weichinger wrote:
> Am 02.01.2014 23:39, schrieb Alan McKinnon:
> 
>> Give BFQ a try, set USE=experimental in *-sources to patch the source
>>
>> euses -sf experimental giove further info and links
> 
> thanks for the hint ...
> 
> edited USE-flags and re-emerging sources ...
> 
> BFQ only for the SSDs ?
> 
> 
> 


Yes. The scheduler knows how to deal with SSDs while keeping everything
responsive even under load.

BFQ seems a good fit for your workcase - desktop/laptop. For those,
interactive performance is the most important thing.


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 07:52, schrieb Alan McKinnon:
> On 03/01/2014 00:46, Stefan G. Weichinger wrote:
>> BFQ only for the SSDs ?
> 
> Yes. The scheduler knows how to deal with SSDs while keeping everything
> responsive even under load.
> 
> BFQ seems a good fit for your workcase - desktop/laptop. For those,
> interactive performance is the most important thing.

So you set BFQ for the SSDs and CFQ for the hdds ? I have both in my
desktop.

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 03/01/2014 09:25, Stefan G. Weichinger wrote:
> Am 03.01.2014 07:52, schrieb Alan McKinnon:
>> On 03/01/2014 00:46, Stefan G. Weichinger wrote:
>>> BFQ only for the SSDs ?
>>
>> Yes. The scheduler knows how to deal with SSDs while keeping everything
>> responsive even under load.
>>
>> BFQ seems a good fit for your workcase - desktop/laptop. For those,
>> interactive performance is the most important thing.
> 
> So you set BFQ for the SSDs and CFQ for the hdds ? I have both in my
> desktop.
> 
> 
> 
> 

BFQ for both is the recommendation.

But do try it both ways to see how it performs and compare.

-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 08:34, schrieb Alan McKinnon:

> BFQ for both is the recommendation.
> 
> But do try it both ways to see how it performs and compare.

sure, thanks.

So I edit my udev-rules (and could leave them away and simply compile
bfq in as default if needed).

Re: [gentoo-user] how to use my SSD the right way ;-)

[William Kenworthy]

On 03/01/14 15:34, Alan McKinnon wrote:
> On 03/01/2014 09:25, Stefan G. Weichinger wrote:
>> Am 03.01.2014 07:52, schrieb Alan McKinnon:
>>> On 03/01/2014 00:46, Stefan G. Weichinger wrote:
>>>> BFQ only for the SSDs ?
>>>
>>> Yes. The scheduler knows how to deal with SSDs while keeping everything
>>> responsive even under load.
>>>
>>> BFQ seems a good fit for your workcase - desktop/laptop. For those,
>>> interactive performance is the most important thing.
>>
>> So you set BFQ for the SSDs and CFQ for the hdds ? I have both in my
>> desktop.
>>
>>
>>
>>
> 
> BFQ for both is the recommendation.
> 
> But do try it both ways to see how it performs and compare.
> 

hmm, is BFQ good for VM's too?  I am currently using noops (storage is
ceph) and was going to experiment but have not had the time yet.

BillK

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 03/01/2014 15:13, William Kenworthy wrote:
> On 03/01/14 15:34, Alan McKinnon wrote:
>> On 03/01/2014 09:25, Stefan G. Weichinger wrote:
>>> Am 03.01.2014 07:52, schrieb Alan McKinnon:
>>>> On 03/01/2014 00:46, Stefan G. Weichinger wrote:
>>>>> BFQ only for the SSDs ?
>>>>
>>>> Yes. The scheduler knows how to deal with SSDs while keeping everything
>>>> responsive even under load.
>>>>
>>>> BFQ seems a good fit for your workcase - desktop/laptop. For those,
>>>> interactive performance is the most important thing.
>>>
>>> So you set BFQ for the SSDs and CFQ for the hdds ? I have both in my
>>> desktop.
>>>
>>>
>>>
>>>
>>
>> BFQ for both is the recommendation.
>>
>> But do try it both ways to see how it performs and compare.
>>
> 
> hmm, is BFQ good for VM's too?  I am currently using noops (storage is
> ceph) and was going to experiment but have not had the time yet.


I have no idea, but I'd like to find out.

Instinct tells me one of the host or guest should be NOOP so that the
other one can get on with scheduling without conflict. But I also reckon
the question is waaaay more complex than that.

I'd like to see the results of any benchmarks you do with BFQ on VMs


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 15:07, schrieb Alan McKinnon:

>> hmm, is BFQ good for VM's too?  I am currently using noops (storage is
>> ceph) and was going to experiment but have not had the time yet.
> 
> 
> I have no idea, but I'd like to find out.
> 
> Instinct tells me one of the host or guest should be NOOP so that the
> other one can get on with scheduling without conflict. But I also reckon
> the question is waaaay more complex than that.
> 
> I'd like to see the results of any benchmarks you do with BFQ on VMs

A bit OT (as it is not exactly benchmarking) but interesting:

http://www.youtube.com/watch?v=J-e7LnJblm8

I also wonder what it does for KVM-hosts etc ... will try!

[gentoo-user] Re: how to use my SSD the right way

[James]

Alan McKinnon <alan.mckinnon <at> gmail.com> writes:


> I'd like to see the results of any benchmarks you do with BFQ on VMs

https://wiki.archlinux.org/index.php/SSD_Benchmarking

is an interesting read on benchmarks and SSD.


https://forums.freebsd.org/viewtopic.php?&t=43358

if you use bonnie++


hth,
James

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 15:07, schrieb Alan McKinnon:

> I'd like to see the results of any benchmarks you do with BFQ on VMs

If we run BFQ on the host (as it runs SSDs and HDDs and we want it to be
snappy) this would maybe mean that in the VMs we need Noop ?

In the IBM-pdf "Best practices for KVM" they tell me to

"use the Deadline I/O scheduler on the KVM host and guest operating
systems for I/O-bound workloads on enterprise storage systems."

But they don't mention BFQ at all.

I can test here on my systems as soon as I find the time and the brains
... or on an upcoming server I will setup within the next weeks for a
customer.

Stefan

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 03/01/2014 23:52, Stefan G. Weichinger wrote:
> Am 03.01.2014 15:07, schrieb Alan McKinnon:
> 
>> I'd like to see the results of any benchmarks you do with BFQ on VMs
> 
> If we run BFQ on the host (as it runs SSDs and HDDs and we want it to be
> snappy) this would maybe mean that in the VMs we need Noop ?
> 
> In the IBM-pdf "Best practices for KVM" they tell me to
> 
> "use the Deadline I/O scheduler on the KVM host and guest operating
> systems for I/O-bound workloads on enterprise storage systems."
> 
> But they don't mention BFQ at all.


that's expected, BFQ isn't in mainline


> 
> I can test here on my systems as soon as I find the time and the brains
> ... or on an upcoming server I will setup within the next weeks for a
> customer.
> 
> Stefan
> 
> 
> 


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 22:59, schrieb Alan McKinnon:

> that's expected, BFQ isn't in mainline

(being lazy): why, btw ?

Re: [gentoo-user] how to use my SSD the right way ;-)

[Alan McKinnon]

On 04/01/2014 00:01, Stefan G. Weichinger wrote:
> Am 03.01.2014 22:59, schrieb Alan McKinnon:
> 
>> that's expected, BFQ isn't in mainline
> 
> (being lazy): why, btw ?
> 
> 
> 
> 


dunno really, it's just not there yet.


-- 
Alan McKinnon
alan.mckinnon@gmail.com

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 23:12, schrieb Alan McKinnon:
> On 04/01/2014 00:01, Stefan G. Weichinger wrote:
>> Am 03.01.2014 22:59, schrieb Alan McKinnon:
>>
>>> that's expected, BFQ isn't in mainline
>>
>> (being lazy): why, btw ?
>>
>>
>>
>>
> 
> 
> dunno really, it's just not there yet.

;-)

currently fiddling with my thinkpad hanging at boot ... so still no BFQ
for that laptop ... :-(

oh my.

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 03.01.2014 23:14, schrieb Stefan G. Weichinger:

> currently fiddling with my thinkpad hanging at boot ... so still no BFQ
> for that laptop ... :-(

I don't get it. My thinkpad hangs repeatedly a booting and I don't
really know how to spot the reason.

As you may remember I run systemd as init-system ... with
gentoo-sources-3.12.6 it boots at least more often than with
USE=experimental ... dunno if it is related to BFQ.

I had those hangs before as well ... for a while I assumed it was
related to the flushing of the systemd-journal but it was not. I even
had masked the flushing but it didn't help.

Maybe I should mask the lvm-stuff as well, maybe I even don't need it at
all? Is it necessary for encrypted partitions as well (sorry for that
stupid q)? I don't have PVs/VGs/LVs on that one small SSD here .... I
just let lvm2 there because I didn't want to break things.

Stefan

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

I consider swapping SSDs ... the Vertex3 from my desktop (replaced by
the new Samsung 840 EVO) could replace the even older Intel SSD.

I assume that the Vertex3 would be faster than the Intel ... (at least
one generation younger).

How to migrate? dd isn't recommended, right?

rsync the partitions one by one? But one of them is encrypted ...

Hints welcome (or even the message that this isn't worth the effort).

Stefan

Re: [gentoo-user] how to use my SSD the right way ;-)

[Neil Bothwick]

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On Mon, 06 Jan 2014 16:31:55 +0100, Stefan G. Weichinger wrote:

> How to migrate? dd isn't recommended, right?
> 
> rsync the partitions one by one? But one of them is encrypted ...

Set up a new encrypted partition and rsync the contents.


-- 
Neil Bothwick

Bagpipe for free: Stuff cat under arm. Pull legs, chew tail.

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Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 06.01.2014 16:40, schrieb Neil Bothwick:
> On Mon, 06 Jan 2014 16:31:55 +0100, Stefan G. Weichinger wrote:
> 
>> How to migrate? dd isn't recommended, right?
>> 
>> rsync the partitions one by one? But one of them is encrypted
>> ...
> 
> Set up a new encrypted partition and rsync the contents.

Yep. Thanks ... could have thought of this as well.

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 06.01.2014 17:16, schrieb Stefan G. Weichinger:
> Am 06.01.2014 16:40, schrieb Neil Bothwick:
>> On Mon, 06 Jan 2014 16:31:55 +0100, Stefan G. Weichinger wrote:
>>
>>> How to migrate? dd isn't recommended, right?
>>>
>>> rsync the partitions one by one? But one of them is encrypted
>>> ...
>>
>> Set up a new encrypted partition and rsync the contents.
> 
> Yep. Thanks ... could have thought of this as well.
> 
> 

in terms of speed, it should be worth the effort:

http://www.harddrivebenchmark.net/hdd.php?hdd=INTEL+SSDSA2M080G2GC

The Vertex3 seems to be way faster.

Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 06.01.2014 17:31, schrieb Stefan G. Weichinger:

> The Vertex3 seems to be way faster.

the vertex3 is 60GB while the older Intel is 80GB ... not so good ...

But I made some small progress in booting the thinkpad with BFQ-enabled
kernel. Somehow the encrypted swap seems to have stopped things.
Disabled it in /etc/fstab and now booted successfully with 3.12.6 and BFQ.

Re: [gentoo-user] how to use my SSD the right way ;-)

[Graham Murray]

Alan McKinnon <alan.mckinnon@gmail.com> writes:

> that's expected, BFQ isn't in mainline

Nor is it in Gentoo hardened-sources.

Re: [gentoo-user] how to use my SSD the right way ;-)

[Daniel Troeder]

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Am 03.01.2014 15:07, schrieb Alan McKinnon:
> On 03/01/2014 15:13, William Kenworthy wrote:
>> On 03/01/14 15:34, Alan McKinnon wrote:
>>> On 03/01/2014 09:25, Stefan G. Weichinger wrote:
>>>> Am 03.01.2014 07:52, schrieb Alan McKinnon:
>>>>> On 03/01/2014 00:46, Stefan G. Weichinger wrote:
>>>>>> BFQ only for the SSDs ?
>>>>>
>>>>> Yes. The scheduler knows how to deal with SSDs while keeping everything
>>>>> responsive even under load.
>>>>>
>>>>> BFQ seems a good fit for your workcase - desktop/laptop. For those,
>>>>> interactive performance is the most important thing.
>>>>
>>>> So you set BFQ for the SSDs and CFQ for the hdds ? I have both in my
>>>> desktop.
>>>>
>>>>
>>>>
>>>>
>>>
>>> BFQ for both is the recommendation.
>>>
>>> But do try it both ways to see how it performs and compare.
>>>
>>
>> hmm, is BFQ good for VM's too?  I am currently using noops (storage is
>> ceph) and was going to experiment but have not had the time yet.
> 
> 
> I have no idea, but I'd like to find out.
> 
> Instinct tells me one of the host or guest should be NOOP so that the
> other one can get on with scheduling without conflict. But I also reckon
> the question is waaaay more complex than that.
A VM should always use noop, as it doesn't know about the physical
layout of the disk (except if you did pass the devices card through...
with a SAS interface over PCIe for example). What IO-scheduler you'd use
for the host depends on your hardware and the desired optimization goal
(throughput vs latency).

My _personal_ opinion for the desktop(!): If you're content with the
general performance I would not optimize for your most common use case
(global maximum), but for the use case that is not-to-uncommon and that
benefits most of it. The idea is, that if most of you life is good, try
to make the remaining part suck less :)

Greetings,
Daniel


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Re: [gentoo-user] how to use my SSD the right way ;-)

[Anton Shumskyi]

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Hi, there is a native queuing at my INTEL SSD 64GB, so i'v set "noop"
scheduler via udev rules. And it's kind a luggish when deleting a lot files
like kernel sources (at ext4,xfs,btrfs, FS makes no difference, some cheap
hardware stuff)​. Will test some day another scheduler like "deadline" on
top of native one at hardware, it's some kernel overhead but hope system
will not freeze for half a minute or more at high I/O....

For me best performance was at XFS, but for you ZFS (or less stable BTRFS)
may be a better choice if you have powerful enough CPU, my 2 core + HT
Intel Atom is too slow for it =(

and fstab options for my XFS (discard = trim option)
attr2,discard,inode64,noquota,relatime

And the best guide is at Arch wiki=) As always=)
https://wiki.archlinux.org/index.php/Solid_State_Drives

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Re: [gentoo-user] how to use my SSD the right way ;-)

[Stefan G. Weichinger]

Am 02.01.2014 23:59, schrieb Anton Shumskyi:

> And the best guide is at Arch wiki=) As always=)
> https://wiki.archlinux.org/index.php/Solid_State_Drives

been there before ;-)

[gentoo-user] Re: how to use my SSD the right way ;-)

[Holger Hoffstätte]

On Fri, 03 Jan 2014 00:59:29 +0200, Anton Shumskyi wrote:

> Hi, there is a native queuing at my INTEL SSD 64GB, so i'v set "noop"
> scheduler via udev rules. And it's kind a luggish when deleting a lot files
> like kernel sources (at ext4,xfs,btrfs, FS makes no difference, some cheap

That's the discard setting. Since kernel 3.8.x the block layer sends TRIMs
synchronously and this totally tanked performance. Just run without discard
and run fstrim nightly.

> hardware stuff)​. Will test some day another scheduler like "deadline" on

Will not help in this case.

-h