Informix on a SAN?

Hello all, We are about to migrate to Informix 11.50 on RHEL5 and are going to put our data chunks on RAID 1+0 drives. However, this morning I learned that it has been proposed that we put these chunks on a SAN instead of the originally proposed server. We are primarily an OLTP shop with some reports getting sprinkled in. Also, we used cooked files instead of raw partitions for our data chunks. I thought that our type of setup on a SAN was an invitation for performance problems and/or corruption issues. While I'm waiting to get access to a SAN to run some tests, can anyone verify this or share their experiences? I would appreciate it greatly. Bonus question: Does SDS work on ext3 with cooked files? Thanks, Joe

Couple of issues: - SANs perform OK as long as: - The channels you use to access them are wide enough and dedicated. Don't make the mistake of piggybacking the SAN on the general datacenter network. They should be on a dedicated ethernet. - Still use RAID 10 and not RAID5, 6, whatever - Filesystem chunks on Linux work OK as long as you configure things properly to use DIRECT IO and KAIO and configure sufficient OS AIO resources. - Filesystem chunks should NEVER be placed on a journaled filesystem like EXT3 unless you disable journaling. Journaling on an IDS chunk is like keeping two sets of logical logs. You get twice the overhead with no extra protection. IDS is using RAW IO and/or DIRECT IO to make confirmed writes directly to disk bypassing the OS buffer pool so there is nothing gained from the filesystem journal in data safety. Your data is 100% secure without the overhead. Art On Wed, Mar 11, 2009 at 11:11 AM, Joseph_Jurcazak@aotx.uscourts.gov < Joseph_Jurcazak@aotx.uscourts.gov> wrote: > Hello all, > > We are about to migrate to Informix 11.50 on RHEL5 and are going to put > our data chunks on RAID 1+0 drives. However, this morning I learned that > it has been proposed that we put these chunks on a SAN instead of the > originally proposed server. We are primarily an OLTP shop with some > reports getting sprinkled in. Also, we used cooked files instead of raw > partitions for our data chunks. I thought that our type of setup on a SAN > was an invitation for performance problems and/or corruption issues. While > I'm waiting to get access to a SAN to run some tests, can anyone verify > this or share their experiences? I would appreciate it greatly. > > Bonus question: Does SDS work on ext3 with cooked files? > > Thanks, > Joe > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. --00163646d5c4815e970464d995e4

Thanks for the reply Art. The SAN setup we are looking at using is a Dual Controller 3GB SAS. Its the HP MSA2012sa. We are not networking the Informix's access to its chunks. Does that sound adequate? Thanks, Joe "Art Kagel" <art.kagel@gmail.com> Sent by: ids-bounces@iiug.org 03/11/2009 10:34 AM Please respond to ids@iiug.org To ids@iiug.org cc Subject Re: Informix on a SAN? [15089] Couple of issues: - SANs perform OK as long as: - The channels you use to access them are wide enough and dedicated. Don't make the mistake of piggybacking the SAN on the general datacenter network. They should be on a dedicated ethernet. - Still use RAID 10 and not RAID5, 6, whatever - Filesystem chunks on Linux work OK as long as you configure things properly to use DIRECT IO and KAIO and configure sufficient OS AIO resources. - Filesystem chunks should NEVER be placed on a journaled filesystem like EXT3 unless you disable journaling. Journaling on an IDS chunk is like keeping two sets of logical logs. You get twice the overhead with no extra protection. IDS is using RAW IO and/or DIRECT IO to make confirmed writes directly to disk bypassing the OS buffer pool so there is nothing gained from the filesystem journal in data safety. Your data is 100% secure without the overhead. Art On Wed, Mar 11, 2009 at 11:11 AM, Joseph_Jurcazak@aotx.uscourts.gov < Joseph_Jurcazak@aotx.uscourts.gov> wrote: > Hello all, > > We are about to migrate to Informix 11.50 on RHEL5 and are going to put > our data chunks on RAID 1+0 drives. However, this morning I learned that > it has been proposed that we put these chunks on a SAN instead of the > originally proposed server. We are primarily an OLTP shop with some > reports getting sprinkled in. Also, we used cooked files instead of raw > partitions for our data chunks. I thought that our type of setup on a SAN > was an invitation for performance problems and/or corruption issues. While > I'm waiting to get access to a SAN to run some tests, can anyone verify > this or share their experiences? I would appreciate it greatly. > > Bonus question: Does SDS work on ext3 with cooked files? > > Thanks, > Joe > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. --00163646d5c4815e970464d995e4 ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.

That should work fine. Keep my other notes in mind (I seem to rememver reading something about EXT3 with journaling disabled is a bit faster than EXT2 - look it up). NO RAID5!!! NO RAID5!!! NO RAID5!!! NO RAID5!!! NO RAID5!!! NO RAID5!!! NO RAID!!! Art On Wed, Mar 11, 2009 at 12:01 PM, Joseph_Jurcazak@aotx.uscourts.gov < Joseph_Jurcazak@aotx.uscourts.gov> wrote: > Thanks for the reply Art. > > The SAN setup we are looking at using is a Dual Controller 3GB SAS. Its > the HP MSA2012sa. We are not networking the Informix's access to its > chunks. Does that sound adequate? > > Thanks, > Joe > > "Art Kagel" <art.kagel@gmail.com> > Sent by: ids-bounces@iiug.org > 03/11/2009 10:34 AM > Please respond to > ids@iiug.org > > To > ids@iiug.org > cc > > Subject > Re: Informix on a SAN? [15089] > > Couple of issues: > > - SANs perform OK as long as: > > - The channels you use to access them are wide enough and dedicated. > > Don't make the mistake of piggybacking the SAN on the general datacenter > > network. They should be on a dedicated ethernet. > > - Still use RAID 10 and not RAID5, 6, whatever > > - Filesystem chunks on Linux work OK as long as you configure things > > properly to use DIRECT IO and KAIO and configure sufficient OS AIO > > resources. > > - Filesystem chunks should NEVER be placed on a journaled filesystem like > > EXT3 unless you disable journaling. Journaling on an IDS chunk is like > > keeping two sets of logical logs. You get twice the overhead with no extra > > protection. IDS is using RAW IO and/or DIRECT IO to make confirmed writes > > directly to disk bypassing the OS buffer pool so there is nothing gained > > from the filesystem journal in data safety. Your data is 100% secure > > without the overhead. > > Art > > On Wed, Mar 11, 2009 at 11:11 AM, Joseph_Jurcazak@aotx.uscourts.gov < > Joseph_Jurcazak@aotx.uscourts.gov> wrote: > > > Hello all, > > > > We are about to migrate to Informix 11.50 on RHEL5 and are going to put > > our data chunks on RAID 1+0 drives. However, this morning I learned that > > > it has been proposed that we put these chunks on a SAN instead of the > > originally proposed server. We are primarily an OLTP shop with some > > reports getting sprinkled in. Also, we used cooked files instead of raw > > partitions for our data chunks. I thought that our type of setup on a > SAN > > was an invitation for performance problems and/or corruption issues. > While > > I'm waiting to get access to a SAN to run some tests, can anyone verify > > this or share their experiences? I would appreciate it greatly. > > > > Bonus question: Does SDS work on ext3 with cooked files? > > > > Thanks, > > Joe > > > > > > > > > > > ******************************************************************************* > > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > -- > Art S. Kagel > Oninit (www.oninit.com) > IIUG Board of Directors (art@iiug.org) > > Disclaimer: Please keep in mind that my own opinions are my own opinions > and > do not reflect on my employer, Oninit, the IIUG, nor any other > organization > with which I am associated either explicitly or implicitly. Neither do > those opinions reflect those of other individuals affiliated with any > entity > with which I am affiliated nor those of the entities themselves. > > --00163646d5c4815e970464d995e4 > > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. --0016364270d241d0950464da43e7

Good morning Joseph, Gladly, I have two different uses of Informix IDS 10.00.FC5 in two different SAN environments. My primary use of Informix with my University's ERP system by Jenzabar. It's on an HPUX system with an EMC Clariion cx700 Fibre-channel SAN. I use LVM manager with logical volumes and asynchronous kernel writes to raw volume space (uncooked file system). The 2nd deployment of Informix is on a RedHat EL 4.7 Intel EMT/64 system (IBM xSever x3550 machine) with a Left-Hand Networks iSCSI SAN. The Left-Hand iSCSI SAN (Raid 10 LUNs) works very well. I was initially skeptical of IP based SAN, because all the performance is usually in hardware and not in software, like fibre-channel, but fibre-channel is $$$ expensive. I was very impressed and surprised by the iSCSI performance of Informix IDS 10.00 on RedHat using LVM managed logical volumes and using the raw disk block device files (i.e. /dev/vgdb/rlovl-root.1, /dev/vgdb/rlvol-dbspace.1, etc., etc.). Bang-for-the-buck, Left-Hand Networks iSCSI SAN performs as well as or better than my fiber-channel SAN for a lot less maintenance and uses commodity hardware. For my Left-Hand iSCSI storage node Intel EMT/64 system, I'm using HP's DL185S SAS Server: http://h18006.www1.hp.com/products/storageworks/dl185g5_ss/index.html And my RedHat w/ Informix 10.00 servers are running on IBM x3550 servers: http://www-304.ibm.com/shop/americas/content/home/store_IBMPublicUSA/en_ US/evp/x3550.html I hope you find this information helpful. Jonathan B. Smaby Pomona College Administrative Information Systems Office on-campus extension: x18506 phone: (909) 621-8506 email: jonathan.smaby@pomona.edu -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Joseph_Jurcazak@aotx.uscourts.gov Sent: Wednesday, March 11, 2009 8:11 AM To: ids@iiug.org Subject: Informix on a SAN? [15087] Hello all, We are about to migrate to Informix 11.50 on RHEL5 and are going to put our data chunks on RAID 1+0 drives. However, this morning I learned that it has been proposed that we put these chunks on a SAN instead of the originally proposed server. We are primarily an OLTP shop with some reports getting sprinkled in. Also, we used cooked files instead of raw partitions for our data chunks. I thought that our type of setup on a SAN was an invitation for performance problems and/or corruption issues. While I'm waiting to get access to a SAN to run some tests, can anyone verify this or share their experiences? I would appreciate it greatly. Bonus question: Does SDS work on ext3 with cooked files? Thanks, Joe ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum. ------------------------------------------------------------- This message has been scanned by Postini anti-virus software.

My 2cents; I was given a Clariion SAN to move a heavily-used OLTP db to, that was configured without my input. I had to take rootspace, logspace, 5 temp spaces and 7 dbspaces and make them fit into 2 large RAID 10 LUNs. It was FC connections from server to SAN. The bottleneck was that there were only the 2 channels for the 2 LUNs. The queues for the 2 LUNs were constantly backed up from all the I/O. My advice; keep as many smaller LUNs as reasonable, so you have as many I/O paths as possible. You want to make use of that multi-threaded architecture. Bob ----- Original Message ----- From: "Jonathan Smaby" <Jonathan.Smaby@pomona.edu> To: ids@iiug.org Sent: Wednesday, March 11, 2009 12:32:26 PM GMT -05:00 US/Canada Eastern Subject: RE: Informix on a SAN? [15092] Good morning Joseph, Gladly, I have two different uses of Informix IDS 10.00.FC5 in two different SAN environments. My primary use of Informix with my University's ERP system by Jenzabar. It's on an HPUX system with an EMC Clariion cx700 Fibre-channel SAN. I use LVM manager with logical volumes and asynchronous kernel writes to raw volume space (uncooked file system). The 2nd deployment of Informix is on a RedHat EL 4.7 Intel EMT/64 system (IBM xSever x3550 machine) with a Left-Hand Networks iSCSI SAN. The Left-Hand iSCSI SAN (Raid 10 LUNs) works very well. I was initially skeptical of IP based SAN, because all the performance is usually in hardware and not in software, like fibre-channel, but fibre-channel is $$$ expensive. I was very impressed and surprised by the iSCSI performance of Informix IDS 10.00 on RedHat using LVM managed logical volumes and using the raw disk block device files (i.e. /dev/vgdb/rlovl-root.1, /dev/vgdb/rlvol-dbspace.1, etc., etc.). Bang-for-the-buck, Left-Hand Networks iSCSI SAN performs as well as or better than my fiber-channel SAN for a lot less maintenance and uses commodity hardware. For my Left-Hand iSCSI storage node Intel EMT/64 system, I'm using HP's DL185S SAS Server: http://h18006.www1.hp.com/products/storageworks/dl185g5_ss/index.html And my RedHat w/ Informix 10.00 servers are running on IBM x3550 servers: http://www-304.ibm.com/shop/americas/content/home/store_IBMPublicUSA/en_ US/evp/x3550.html I hope you find this information helpful. Jonathan B. Smaby Pomona College Administrative Information Systems Office on-campus extension: x18506 phone: (909) 621-8506 email: jonathan.smaby@pomona.edu -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Joseph_Jurcazak@aotx.uscourts.gov Sent: Wednesday, March 11, 2009 8:11 AM To: ids@iiug.org Subject: Informix on a SAN? [15087] Hello all, We are about to migrate to Informix 11.50 on RHEL5 and are going to put our data chunks on RAID 1+0 drives. However, this morning I learned that it has been proposed that we put these chunks on a SAN instead of the originally proposed server. We are primarily an OLTP shop with some reports getting sprinkled in. Also, we used cooked files instead of raw partitions for our data chunks. I thought that our type of setup on a SAN was an invitation for performance problems and/or corruption issues. While I'm waiting to get access to a SAN to run some tests, can anyone verify this or share their experiences? I would appreciate it greatly. Bonus question: Does SDS work on ext3 with cooked files? Thanks, Joe ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum. ------------------------------------------------------------- This message has been scanned by Postini anti-virus software. ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.