linux-kernel - Linux and SSD and how to decrease io delay : question, please

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <847418.75727.qm@web35715.mail.mud.yahoo.com>
Date:	Tue, 19 Feb 2008 16:02:13 -0800 (PST)
From:	Mariella Petrini <mariellapetrini@...oo.com>
To:	linux-kernel@...r.kernel.org
Subject: Linux and SSD and how to decrease io delay : question, please

Hi All,

I have been running Linux kernel 2.6.23 with Debian on

a 2 CPUs Dual-Core AMD Opteron(tm) Processor 2218.
I have been using an SSD drive (MTRON) connected to a
raid controller (LSI      MegaRAID 8704ELP) to contain
data stored on several databases.
Each database contains 20,000 files and there are 50
databases total (1,000,000 files distributed across 50
directories on the filesystem on the ssd).

The database server uses the databases very "write"
intensively.
An approximate percentage could be 20% reads versus
80% random writes.

No matter which filesystem type is used (I have tried
ext3, xfs, jfs, reiserfs) I see every few seconds
snapshots (the could last in the worst case up to 200
seconds, depending on the filesystem type) 
where the iowait on the ssd device goes approximately
over 50% (up to 100%) and 
the database server threads go to wait (get
suspended).

Is there any Linux kernel parameter or any Linux
parameter that could be varied that could help to
decrease the time spent to sync all the data to the
SSD device ?

Thanks in advance for your help,

Mariella

      ____________________________________________________________________________________
Be a better friend, newshound, and 
know-it-all with Yahoo! Mobile.  Try it now.  http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/