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Mgruben
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Linux SSD question

Hey all,

So I just put up a new Linux rig
(Ubuntu desktop 12.04 amd64, i5 3470T processor, 4gb ram,
AND a Mushkin Enhanced 60GB solid state drive).

I'm a Linux newbie, so bear with me, but I've been with WCG for about 2 months now.

Long story short, I installed iotop and ran sudo iotop -a, and am seeing that an "idle boinc" process manages to do a few MB of disk writes every second.

Needless to say, I am troubled, as I have my client set to write to disk no more than every 900 seconds (since I hear this cuts down on SSD exhaustion).

The SWAPIN and IO> columns are both at 0.00% for that process, and the COMMAND reads (enigmatically) "../../projects/www.wor~193244926253088 40002 0"

There's also another "idle boinc" process which writes about a tenth as much, but still enough for me to be concerned about it, whose SWAPIN and IO> are also both 0.00%, and whose COMMAND is "../../projects/www.wor~_00.gpf -seed 225534140"

In closing, halp. I'm not sure if I should be concerned about the high DISK WRITE numbers, and if I should be concerned how I can get them to shtahp.

edit: iostat readings:
Linux 3.5.0-37-generic (Linus) 08/10/2013 _x86_64_ (4 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
4.31 89.02 2.20 0.04 0.00 4.42
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sda 0.92 5.95 1.65 4.22 84.88 916.95 341.33 0.41 69.41 2.08 95.67 2.00 1.18
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[Edit 1 times, last edit by Mgruben at Aug 10, 2013 11:14:53 PM]
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OldChap
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Re: Linux SSD question

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[Edit 1 times, last edit by OldChap at Aug 11, 2013 1:08:51 AM]
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Sgt.Joe
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Re: Linux SSD question

Which projects are you running ?
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Sgt. Joe
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Mgruben
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Re: Linux SSD question

I'm signed up for all of them, and have changed CEP2 to be able to run more than 1 WU at a time (OldChap I've yet to go through your reading list)
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[Aug 11, 2013 1:45:03 AM]   Link   Report threatening or abusive post: please login first  Go to top 
Mgruben
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Re: Linux SSD question

OldChap,

Will be going out of town tomorrow (not able to access the BIOS), but those resources look great (accurate and exhaustive), and I'll be sure to give them a look when I have the ability to sit down in front of the terminal again
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[Aug 11, 2013 3:03:13 AM]   Link   Report threatening or abusive post: please login first  Go to top 
Mgruben
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Re: Linux SSD question

The easylinuxtipsproject/ssd helped a great deal; I'm down to very low (a few kB/s) writes per second according to iotop -a, even running a CEP2 work unit

Thanks again for the advice
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[Aug 18, 2013 5:03:56 PM]   Link   Report threatening or abusive post: please login first  Go to top 
OldChap
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Re: Linux SSD question

wink
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[Aug 18, 2013 9:29:35 PM]   Link   Report threatening or abusive post: please login first  Go to top 
KerSamson
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Re: Linux SSD question

Since 3 years, I use SSD on two hexacore Linux hosts (still 10.04, i.e. no trim available).
The decision to switch to SSD was caused by the launch of CEP2.
Finally, excepted for CEP2 (with more than two simultaneously computed WUs), the performance improvement of SSD is really not significant.

All my hosts - using HDD or SSD - reach an average CPU performance better than 99.20% (according to boinctask).
The improvement for CEP2 is less than 0.5% for one or two WUs, and around 1% for 6 simultaneously computed WUs.

Additionally to a fast boot-up (but the systems are running 24/7/365), the only advantage using SSD are consumption and noise (?) however ventirad and power supply are more noisy than an HDD.

In few words:
The performance improvement brought by SSD is really small for WCG projects.

Cheers,
Yves
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[Aug 30, 2013 9:14:01 AM]   Link   Report threatening or abusive post: please login first  Go to top 
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