Re: [GENERAL] Hardware related question: 3ware 9500S
Merlin Moncure writes: escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy. Their S line is not native sata but operates over a pata-sata bridge. Stay away from raid 5. Do you know if their raid 5 is better in the new 9550SX? Or is the Stay away from raid 5 more of a general comment that this type of raid is not good for DBs? ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [GENERAL] Hardware related question: 3ware 9500S
Merlin Moncure writes: there are reasons to go with raid 5 or other raids. where I work we often do 14 drive raid 6 plus 1 hot swap on a 15 drive tray. Raid 5 is different from raid 6 To say that there are times it's ok to use RAID 5 and then say you use raid 6... well... doesn't really say anything about raid 5. Also, what controller are you using? From what I gather, raid 6 is less common and fewer cards support it (areca is one of them I believe). ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [GENERAL] Hardware related question: 3ware 9500S
Raid 5 on the 9550SX is supposed to be significantly better than the 9500 series.I would be carefull of benchmarks listed out there. For instance, whilst looking for supporting material, I came cross this gem: http://www.gamepc.com/labs/print_content.asp?id=9550sx4lpcookie%5Ftest=1 They claim the they used a Tyan Thunder K8WE motherboard, and installed the RAID controllers in a 64-bit 133MHz PCI-X slot. This motherboard doesn't have any 64-bit 133Mhz PCI-X slots! ( http://www.tyan.com/products/html/tigerk8we_spec.html).It's no wonder that the other raid controllers showed significantly less performance than the PCI-e card. This review from tomshardware:http://www.tomshardware.com/2005/10/31/sata_spells_trouble_for_scsi_raid/page13.html Suggests that the 9550SX is at least competitive with the others.I know I like the 3ware/AMCC cards because of their very good RAID 10 performance. I'm not a big RAID 5 fan. RAID 5 sufferes the read before write penalty problem that make RAID 5 writes very slow, particularly noticebale in OLTP applications. RAID 10 will almost always offer better write perfomance. I wish we could set up an organization to do benchmarks with pgbench on various different RAID controllers/drives and publish the results. I know I would pay money for that.Alex On 4/15/06, Francisco Reyes [EMAIL PROTECTED] wrote: Merlin Moncure writes: escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy.Their S line is not native sata but operates over a pata-sata bridge.Stay away from raid 5.Do you know if their raid 5 is better in the new 9550SX?Or is the Stay away from raid 5 more of a general comment that this type of raid is not good for DBs?---(end of broadcast)---TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [GENERAL] Hardware related question: 3ware 9500S
Alex Turner wrote: Raid 5 on the 9550SX is supposed to be significantly better than the 9500 series. I would be carefull of benchmarks listed out there. For instance, whilst looking for supporting material, I came cross this gem: http://www.gamepc.com/labs/print_content.asp?id=9550sx4lpcookie%5Ftest= 1 They claim the they used a Tyan Thunder K8WE motherboard, and installed the RAID controllers in a 64-bit 133MHz PCI-X slot. This motherboard doesn't have any 64-bit 133Mhz PCI-X slots! ( http://www.tyan.com/products/html/tigerk8we_spec.html). It's no wonder that the other raid controllers showed significantly less performance than the PCI-e card. You're looking at the wrong board. They are talking about the Tyan *Thunder*, which does indeed have 64-bit PCI-X. You are looking at the Tyan **Tiger**, which does not. -- Guy Rouillier ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [GENERAL] Hardware related question: 3ware 9500S
Alex Turner writes: Suggests that the 9550SX is at least competitive with the others. Thanks for the links. I know I like the 3ware/AMCC cards because of their very good RAID 10 performance. Raid 10 is what I used on my last server and likely what I will use on the next. I wish we could set up an organization to do benchmarks with pgbench on various different RAID controllers/drives and publish the results. I know I would pay money for that. Yes. That would be truly very usefull, although it would be very time consuming. ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [GENERAL] Hardware related question: 3ware 9500S
I have the time to do it, but not the $$s ;)AlexOn 4/15/06, Francisco Reyes [EMAIL PROTECTED] wrote:Alex Turner writes: Suggests that the 9550SX is at least competitive with the others. Thanks for the links. I know I like the 3ware/AMCC cards because of their very good RAID 10 performance.Raid 10 is what I used on my last server and likely what I will use on thenext. I wish we could set up an organization to do benchmarks with pgbench on various different RAID controllers/drives and publish the results. I know I would pay money for that.Yes. That would be truly very usefull, although it would be very time consuming.
Re: [GENERAL] Hardware related question: 3ware 9500S
A... good point.Why oh why does tyan have two boards with the same prefix ;)!!!AlexOn 4/15/06, Guy Rouillier [EMAIL PROTECTED] wrote:Alex Turner wrote: Raid 5 on the 9550SX is supposed to be significantly better than the 9500 series. I would be carefull of benchmarks listed out there.For instance, whilst looking for supporting material, I came cross this gem: http://www.gamepc.com/labs/print_content.asp?id=9550sx4lpcookie%5Ftest=1 They claim the they used a Tyan Thunder K8WE motherboard, and installed the RAID controllers in a 64-bit 133MHz PCI-X slot.This motherboard doesn't have any 64-bit 133Mhz PCI-X slots! ( http://www.tyan.com/products/html/tigerk8we_spec.html). It's no wonder that the other raid controllers showed significantly less performance than the PCI-e card.You're looking at the wrong board.They are talking about the Tyan*Thunder*, which does indeed have 64-bit PCI-X.You are looking at theTyan **Tiger**, which does not. --Guy Rouillier---(end of broadcast)---TIP 2: Don't 'kill -9' the postmaster
[GENERAL] Hardware related question: 3ware 9500S
Hi, i don't know much about hard disks and raid controllers but often there is some discussion about which raid controller rocks and which sucks. my hosting company offers me a raid 10 with 4 serial-ata disks. They will use a 3ware 4-Port-RAID-Controller 9500S More than 4 disks are not possible. Most operations and all time-critical operations are read-only using a lot of indices. My partioning plans are like this: disk 1: OS, tablespace disk 2: indices, WAL, Logfiles - Does my partitioning make sense? - I want to know if 3ware 9500 S is recommended or if its one of those controllers which sucks. kind regards, janning ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
Re: [GENERAL] Hardware related question: 3ware 9500S
On 4/12/06, Janning Vygen [EMAIL PROTECTED] wrote: Hi, disk 1: OS, tablespace disk 2: indices, WAL, Logfiles - Does my partitioning make sense? with raid 10 all four drives will appear as a single physical device shared by all. I'm personally not a big fan of logical partitioning of a single raid device unless you are trying to keep a physical volume under 1 TB for example. Each sync on the volume is guaranteed to sync all 4 disks regardless of how you set your partitions up. - I want to know if 3ware 9500 S is recommended or if its one of those controllers which sucks. escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy. Their S line is not native sata but operates over a pata-sata bridge. Stay away from raid 5. merlin ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [GENERAL] Hardware related question: 3ware 9500S
Thanks for your fast reply. Am Mittwoch, 12. April 2006 18:31 schrieb Merlin Moncure: On 4/12/06, Janning Vygen [EMAIL PROTECTED] wrote: Hi, disk 1: OS, tablespace disk 2: indices, WAL, Logfiles - Does my partitioning make sense? with raid 10 all four drives will appear as a single physical device shared by all. I'm personally not a big fan of logical partitioning of a single raid device unless you are trying to keep a physical volume under 1 TB for example. Each sync on the volume is guaranteed to sync all 4 disks regardless of how you set your partitions up. Ok, i am not a raid expert. but in my understanding RAID 10 is faster than two RAID 1 arrays, aren't they? So, given that i can put up to 4 S-ATA disk in my server and the mentioned raid controller. Would you prefer no-raid, RAID1 or RAID 10? - I want to know if 3ware 9500 S is recommended or if its one of those controllers which sucks. escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy. Their S line is not native sata but operates over a pata-sata bridge. Stay away from raid 5. thanks for your recommendation. ford taurus is ok for me :-) kind regrads janning ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
Re: [GENERAL] Hardware related question: 3ware 9500S
- Original Message - From: Merlin Moncure [EMAIL PROTECTED] To: Janning Vygen [EMAIL PROTECTED] Cc: pgsql-general@postgresql.org Sent: Wednesday, April 12, 2006 12:31 PM Subject: Re: [GENERAL] Hardware related question: 3ware 9500S [snip] - I want to know if 3ware 9500 S is recommended or if its one of those controllers which sucks. escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy. Their S line is not native sata but operates over a pata-sata bridge. Stay away from raid 5. Hi Merlin Why? What's wrong with raid 5? I could well be wrong (given how little attention I have paid to hardware over the past few years because of a focus on developing software), but I was under the impression that of the raid options available, raid 5 with hot swappable drives provided good data protection and performance at a reasonably low cost. Is the problem with the concept of raid 5, or the common implementations? Do you have a recommendation regarding whether the raid array is built into the server running the RDBMS (in our case PostgreSQL), or located in a network appliance dedicated to storing the data managed by the RDBMS? If you were asked to design a subnet that provides the best possible performance and protection of the data, but without gold-plating anything, what would you do? How much redundancy would you build in, and at what granularity? Ted ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [GENERAL] Hardware related question: 3ware 9500S
On Wed, 2006-04-12 at 13:10, Ted Byers wrote: - Original Message - From: Merlin Moncure [EMAIL PROTECTED] To: Janning Vygen [EMAIL PROTECTED] Cc: pgsql-general@postgresql.org Sent: Wednesday, April 12, 2006 12:31 PM Subject: Re: [GENERAL] Hardware related question: 3ware 9500S [snip] - I want to know if 3ware 9500 S is recommended or if its one of those controllers which sucks. escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy. Their S line is not native sata but operates over a pata-sata bridge. Stay away from raid 5. Hi Merlin Why? What's wrong with raid 5? I could well be wrong (given how little attention I have paid to hardware over the past few years because of a focus on developing software), but I was under the impression that of the raid options available, raid 5 with hot swappable drives provided good data protection and performance at a reasonably low cost. Is the problem with the concept of raid 5, or the common implementations? Do you have a recommendation regarding whether the raid array is built into the server running the RDBMS (in our case PostgreSQL), or located in a network appliance dedicated to storing the data managed by the RDBMS? If you were asked to design a subnet that provides the best possible performance and protection of the data, but without gold-plating anything, what would you do? How much redundancy would you build in, and at what granularity? There have been NUMEROUS discussions of RAID-5 versus RAID 1+0 in the perform group in the last year or two. Short version: RAID 5 is useful, with large numbers of drives, for OLAP type databases, where you're trying to get as much storage as possible from your drives. RAID 5 pretty much REQUIRES battery backed cache for decent write performance, and even then, will saturate faster than RAID 1+0. RAID-5 cannot survive multiple simultaneous drive failures. RAID 1+0 requires better than average controllers, since many serialize and lockstep data through the various layers of RAID on them. It provides less storage for a given number of drives. It is faster for OLTP workloads than RAID-5. RAID 1+0 can survive multiple drive failures as long as two drives in the same mirror set do not fail at once. With increasing number of drives, the chances of a RAID 5 failing go up linearly, while the chances of RAID 1+0 failing due to multiple drive failure stay the same. ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [GENERAL] Hardware related question: 3ware 9500S
- Original Message - From: Scott Marlowe [EMAIL PROTECTED] To: Ted Byers [EMAIL PROTECTED] Cc: Merlin Moncure [EMAIL PROTECTED]; Janning Vygen [EMAIL PROTECTED]; pgsql general pgsql-general@postgresql.org Sent: Wednesday, April 12, 2006 2:24 PM Subject: Re: [GENERAL] Hardware related question: 3ware 9500S On Wed, 2006-04-12 at 13:10, Ted Byers wrote: - Original Message - From: Merlin Moncure [EMAIL PROTECTED] To: Janning Vygen [EMAIL PROTECTED] Cc: pgsql-general@postgresql.org Sent: Wednesday, April 12, 2006 12:31 PM Subject: Re: [GENERAL] Hardware related question: 3ware 9500S [snip] Why? What's wrong with raid 5? I could well be wrong (given how little attention I have paid to hardware over the past few years because of a focus on developing software), but I was under the impression that of the raid options available, raid 5 with hot swappable drives provided good data protection and performance at a reasonably low cost. Is the problem with the concept of raid 5, or the common implementations? Do you have a recommendation regarding whether the raid array is built into the server running the RDBMS (in our case PostgreSQL), or located in a network appliance dedicated to storing the data managed by the RDBMS? If you were asked to design a subnet that provides the best possible performance and protection of the data, but without gold-plating anything, what would you do? How much redundancy would you build in, and at what granularity? There have been NUMEROUS discussions of RAID-5 versus RAID 1+0 in the perform group in the last year or two. Short version: Interesting. I take it that RAID 1+0 refers to a combination of Raid 1 and RAID 0. What about RAID 10? I am curious because RAID 10 has come out since the last time I took a look at RAID technology. I am not sure what it actually does differently from RAID 5. This question of data security is becoming of increasing importance to me professionally since I will soon have to advise the company I'm working with regarding how best to secure the data managed by the applications I'm developing for them. I will need overall guidelines to produce a design that makes it virtually impossible for them to lose even on field in one record. The data is both sensitive and vital. Fortunately, I have a few months before we need to commit to anything. Also, fortunately, with one exception, the applications rely on a data feed that comes in once a day after normal working hours, so I won't have to worry about writes to the DB other than what my script does to load the datafeed into the DB. All other access is read only. This should make it easier to produce a strategy to protect the data from any kind of technology failure (software or hardware). Cost is a factor, but reliability is much much more important! Thanks, Ted ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [GENERAL] Hardware related question: 3ware 9500S
On Wed, Apr 12, 2006 at 02:53:01PM -0400, Ted Byers wrote: I take it that RAID 1+0 refers to a combination of Raid 1 and RAID 0. What about RAID 10? I am curious because RAID 10 has come out since the last time I took a look at RAID technology. I am not sure what it actually does differently from RAID 5. AIUI, RAID 10 = RAID 1+0. Lame, I know. Similarly, some people have invented RAID 50 = RAID 5+0. Not sure if that's the official definition though, but that's the way I've seen it used. -- Martijn van Oosterhout kleptog@svana.org http://svana.org/kleptog/ Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a tool for doing 5% of the work and then sitting around waiting for someone else to do the other 95% so you can sue them. signature.asc Description: Digital signature
Re: [GENERAL] Hardware related question: 3ware 9500S
Martijn van Oosterhout wrote: On Wed, Apr 12, 2006 at 02:53:01PM -0400, Ted Byers wrote: I take it that RAID 1+0 refers to a combination of Raid 1 and RAID 0. What about RAID 10? I am curious because RAID 10 has come out since the last time I took a look at RAID technology. I am not sure what it actually does differently from RAID 5. AIUI, RAID 10 = RAID 1+0. Lame, I know. Similarly, some people have invented RAID 50 = RAID 5+0. Not sure if that's the official definition though, but that's the way I've seen it used. Useful info on RAID definitions: http://tinyurl.com/zhnmc -- Until later, Geoffrey Any society that would give up a little liberty to gain a little security will deserve neither and lose both. - Benjamin Franklin ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [GENERAL] Hardware related question: 3ware 9500S
On 4/12/06, Ted Byers [EMAIL PROTECTED] wrote: - Original Message - From: Merlin Moncure [EMAIL PROTECTED] To: Janning Vygen [EMAIL PROTECTED] Cc: pgsql-general@postgresql.org Sent: Wednesday, April 12, 2006 12:31 PM Subject: Re: [GENERAL] Hardware related question: 3ware 9500S [snip] - I want to know if 3ware 9500 S is recommended or if its one of those controllers which sucks. escalade is a fairly full featured raid controller for the price. consider it the ford taurus of raid controllers, it's functional and practical but not sexy. Their S line is not native sata but operates over a pata-sata bridge. Stay away from raid 5. Hi Merlin Why? What's wrong with raid 5? I could well be wrong (given how little there are reasons to go with raid 5 or other raids. where I work we often do 14 drive raid 6 plus 1 hot swap on a 15 drive tray. However, for 4 drive raid, I think 0+1 is the by far the best choice. For three drive, I'd suggest two drive raid 1 plus hot swap. Do you have a recommendation regarding whether the raid array is built into the server running the RDBMS (in our case PostgreSQL), or located in a network appliance dedicated to storing the data managed by the RDBMS? If you were asked to design a subnet that provides the best possible performance and protection of the data, but without gold-plating anything, what would you do? How much redundancy would you build in, and at what granularity? I would stay clear of cheaper NAS solutions (AoE, iscsi) unless you really didn't care about performance. In my experience the better SANs are a good way to go if you need flexibility or easy managment (especially if you need to do things besides database) without losing performance. A good SAN makes everything easy but boy do you pay for it. If you want most bang for the buck, I'd suggest either attached scsi or sata (especially the latter). With sata, 24 raptors will get you insane performance for a very reasonable price. Most of my apps are cpu bound anyways. ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
