Hi all,
YMMV, I've really never played with these, but check
/sys/block/sdX/queue/nr_requests and some other files in that dir
ow BTW, google is your friend ;-)
On 21 okt 2010, at 19:38, Zoltan Forray/AC/VCU wrote:
> This is RedHat Linux 5.5
>
>
>
> From:
> Remco Post <r.post AT PLCS DOT NL>
> To:
> ADSM-L AT VM.MARIST DOT EDU
> Date:
> 10/21/2010 01:24 PM
> Subject:
> Re: [ADSM-L] Lousy performance on new 6.2.1.1 server with SAN/FILEDEVCLASS
> storage
> Sent by:
> "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
>
>
>
> for AIX:
>
> lsattr -l hdiskX -> look foor the queue_depth field values between 20 and
> 64 make sense, 128 in some extreme cases
> chdev -l hdiskX -a queue_depth=Y (but only if the vg is off-line)
>
> I found that some drives only support a queue_depth of 1... in that case,
> you found your bottleneck.
>
> On 21 okt 2010, at 18:57, Zoltan Forray/AC/VCU wrote:
>
>> In reference to these recommendations, this is what one of my SAN folks
>> said:
>>
>> If "increasing the queue depth for the individual disks" is something
> you
>> can do on a CLARiiON, it's not something I'm familiar with. On the HBA
>> (and if you can), you would do that from the host side (like with
>> SanSurfer for Qlogic HBAs).
>>
>> I have no idea what he might be referring to with "EMC voodoo
>> application".
>>
>> "iostat/vmstat" are unix host utilities.
>>
>> Each of the two LUNs is spread out over 7 disks. The 2 RAID Groups and
>> the enclosure they are in are dedicated to Tivoli.
>>
>> I've seen some references to using lots of smaller LUNs rather than a
> few
>> big ones. You have 2 5.5TB LUNs now. We can try splitting each of
> those
>> into 10-12 smaller LUNs.
>> Zoltan Forray
>> TSM Software & Hardware Administrator
>> Virginia Commonwealth University
>> UCC/Office of Technology Services
>> zforray AT vcu DOT edu - 804-828-4807
>> Don't be a phishing victim - VCU and other reputable organizations will
>> never use email to request that you reply with your password, social
>> security number or confidential personal information. For more details
>> visit http://infosecurity.vcu.edu/phishing.html
>>
>>
>>
>> From:
>> "Strand, Neil B." <NBStrand AT LEGGMASON DOT COM>
>> To:
>> ADSM-L AT VM.MARIST DOT EDU
>> Date:
>> 10/19/2010 01:50 PM
>> Subject:
>> Re: [ADSM-L] Lousy performance on new 6.2.1.1 server with
> SAN/FILEDEVCLASS
>> storage
>> Sent by:
>> "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
>>
>>
>>
>> Zoltan,
>> You may need to increase the queue depth for the individual disks
>> and/or the HBA attached to the disks.
>> Monitor both the server (iostat/vmstat) and the storage (EMC voodoo
>> application) for latency and compare the results for consistency. You
>> may need to adjust the striping of your logical LUNs on the storage. I
>> have observed serious performance degradation on an older IBM ESS simply
>> because the logical volumes were created on a single SSA rather than
>> spread across the entire set of disks.
>>
>> Cheers,
>> Neil Strand
>> Storage Engineer - Legg Mason
>> Baltimore, MD.
>> (410) 580-7491
>> Whatever you can do or believe you can, begin it.
>> Boldness has genius, power and magic.
>>
>>
>> -----Original Message-----
>> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf
>> Of
>> Zoltan Forray/AC/VCU
>> Sent: Tuesday, October 19, 2010 9:15 AM
>> To: ADSM-L AT VM.MARIST DOT EDU
>> Subject: [ADSM-L] Lousy performance on new 6.2.1.1 server with
>> SAN/FILEDEVCLASS storage
>>
>> Now that I have ventured into new territory with this new server (Linux
>> 6.2.1.1), I am experiencing terrible performance when it comes to moving
>> data from disk (FILEDEVCLASS on EMC/SAN storage) vs my other 6.1 and 5.5
>> servers.
>>
>> With the server doing nothing but migrating data from this SAN based
>> stgpool to TS1130 tape, I am seeing roughly 700GB being moved in a
>> 12-hour
>> period. On my other, internal disk based TSM servers, I move
>> multiple-terabytes per day/24-hours.
>>
>> So, where should I focus on why this is so slow? Is it because I am
>> using
>> SAN storage? How about the FILEDEVCLASS vs fixed, pre-formatted volumes
>> (like every other server is using)?
>>
>> Or is this normal? If it is, I am in for some serious problems. One of
>> these servers is expected to replace an existing 5.5 server that
>> processes
>> 20TB+ of backups, per week (no, I can not go straight to tape due to the
>> type of backups being performed).
>>
>> Suggestions? Thoughts?
>> Zoltan Forray
>> TSM Software & Hardware Administrator
>> Virginia Commonwealth University
>> UCC/Office of Technology Services
>> zforray AT vcu DOT edu - 804-828-4807
>> Don't be a phishing victim - VCU and other reputable organizations will
>> never use email to request that you reply with your password, social
>> security number or confidential personal information. For more details
>> visit http://infosecurity.vcu.edu/phishing.html
>>
>> IMPORTANT: E-mail sent through the Internet is not secure. Legg Mason
>> therefore recommends that you do not send any confidential or sensitive
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> numbers,
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>>
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>> Thank you.
>
> --
> Met vriendelijke groeten/Kind Regards,
>
> Remco Post
> r.post AT plcs DOT nl
> +31 6 248 21 622
--
Met vriendelijke groeten/Kind Regards,
Remco Post
r.post AT plcs DOT nl
+31 6 248 21 622
|
