ESRP – Silverton Consulting

Latest ESRP results for 1K and under mailboxes – chart of the month

Posted on September 13, 2012October 8, 2012 by Ray in Block Storage, Disk storage, ESRP, ESRPv3/Exchange 2010, Ethernet, iSCSI, Storage, Storage performance

The above chart was from our July newsletter Exchange Solution Reviewed Program (ESRP) performance analysis for 1000 and under mailbox submissions. I have always liked response times as they seem to be mostly the result of tight engineering, coding and/or system architecture. Exchange response times represent a composite of how long it takes to do a database transaction (whether read, write or log write). Latencies are measured at the application (Jetstress) level.

On the chart we show the top 10 data base read response times for this class of storage. We assume that DB reads are a bit more important than writes or log activity but they are all probably important. As such, we also show the response times for DB writes and log writes but the ranking is based on DB reads alone.

In the chart above, I am struck by the variability in write and log write performance. Writes range anywhere from ~8.6 down to almost 1 msec. The extreme variability here begs a bunch of questions. My guess is the wide variability probably signals something about caching, whether it’s cache size, cache sophistication or drive destage effectiveness is hard to say.

Why EMC seems to dominate DB read latency in this class of storage is also interesting. EMC’s Celerra NX4, VNXe3100, CLARiiON CX4-120, CLARiiON AX4-5i, Iomega ix12-300 and VNXe3300 placed in the top 6 slots, respectively. They all had a handful of disks (4 to 8), mostly 600GB or larger and used iSCSI to access the storage. It’s possible that EMC has a great iSCSI stack, better NICs or just better IO scheduling. In any case, they have done well here at least with read database latencies. However, their write and log latency was not nearly as good.

We like ESRP because it simulates a real application that’s pervasive in the enterprise today, i.e., email. As such, it’s less subject to gaming, and typically shows a truer picture of multi-faceted storage performance.

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The complete ESRP performance report with more top 10 charts went out in SCI’s July newsletter. But a copy of the report will be posted on our dispatches page sometime next month (if all goes well). However, you can get the ESRP performance analysis now and subscribe to future free newsletters by just using the signup form above right.

For a more extensive discussion of current SAN block system storage performance covering SPC (Top 30) results as well as ESRP results with our new ChampionsChart™ for SAN storage systems, please see SCI’s SAN Storage Buying Guide available from our website.

As always, we welcome any suggestions or comments on how to improve our analysis of ESRP results or any of our other storage performance analyses.

Latest ESRP 1K-5K mailbox DB xfers/sec/disk results – chart-of-the-month

Posted on June 19, 2012October 8, 2012 by Ray in Block Storage, DAS, Disk storage, ESRP, ESRPv3/Exchange 2010, Ethernet, iSCSI, SAS, Storage performance, System effectiveness

(SCIESRP120429-001) 2012 (c) Silverton Consulting, All Rights Reserved

The above chart is from our April newsletter on Microsoft Exchange 2010 Solution Reviewed Program (ESRP) results for the 1,000 (actually 1001) to 5,000 mailbox category. We have taken the database transfers per second, normalized them for the number of disk spindles used in the run and plotted the top 10 in the chart above.

A couple of caveats first, we chart disk-only systems in this and similar charts on disk spindle performance. Although, it probably doesn’t matter as much at this mid-range level, for other categories SSD or Flash Cache can be used to support much higher performance on a per spindle performance measure like the above. As such, submissions with SSDs or flash cache are strictly eliminated from these spindle level performance analysis.

Another caveat, specific to this chart is that ESRP database transaction rates are somewhat driven by Jetstress parameters (specifically simulated IO rate) used during the run. For this mid-level category, this parameter can range from a low of 0.10 to a high of 0.60 simulated IO operations per second with a median of ~0.19. But what I find very interesting is that in the plot above we have both the lowest rate (0.10 in #6, Dell PowerEdge R510 1.5Kmbox) and the highest (0.60 for #9, HP P2000 G3 10GbE iSCSI MSA 3.2Kmbx). So that doesn’t seem to matter much on this per spindle metric.

That being said, I always find it interesting that the database transactions per second per disk spindle varies so widely in ESRP results. To me this says that storage subsystem technology, firmware and other characteristics can still make a significant difference in storage performance, at least in Exchange 2010 solutions.

Often we see spindle count and storage performance as highly correlated. This is definitely not the fact for mid-range ESRP (although that’s a different chart than the one above).

Next, we see disk speed (RPM) can have a high impact on storage performance especially for OLTP type workloads that look somewhat like Exchange. However, in the above chart the middle 4 and last one (#4-7 & 10) used 10Krpm (#4,5) or slower disks. It’s clear that disk speed doesn’t seem to impact Exchange database transactions per second per spindle either.

Thus, I am left with my original thesis that storage subsystem design and functionality can make a big difference in storage performance, especially for ESRP in this mid-level category. The range in the top 10 contenders spanning from ~35 (Dell PowerEdge R510) to ~110 (Dell EqualLogic PS Server) speaks volumes on this issue or a multiple of over 3X from top to bottom performance on this measure. In fact, the overall range (not shown in the chart above spans from ~3 to ~110 which is a factor of almost 37 times from worst to best performer.

Comments?

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The full ESRP 1K-5Kmailbox performance report went out in SCI’s April newsletter. But a copy of the full report will be posted on our dispatches page sometime next month (if all goes well). However, you can get the full SPC performance analysis now and subscribe to future free newsletters by just sending us an email or using the signup form above right.

For a more extensive discussion of current SAN or block storage performance covering SPC-1 (top 30), SPC-2 (top 30) and all three levels of ESRP (top 20) results please see SCI’s SAN Storage Buying Guide available on our website.

As always, we welcome any suggestions or comments on how to improve our analysis of ESRP results or any of our other storage performance analyses.

SCI’s Latest ESRP (v3) Performance Analysis for Over 5K mailboxes – chart of the month

Posted on February 14, 2012October 8, 2012 by Ray in Block Storage, Disk storage, ESRP, ESRPv3/Exchange 2010, Storage, Storage Backup, Storage performance, System effectiveness

Bar chart showing ESRP Top 10 total database backup throughput results — (SCIESRP120125-001) (c) 2012 Silverton Consulting, All Rights Reserved

This chart comes from our analysis of Microsoft Exchange Reviewed Solutions Program (ESRP) v3 (Exchange 2010) performance results for the over 5000 mailbox category, a report sent out to SCI Storage Intelligence Newsletter subscribers last month.

The total database backup throughput reported here is calculated based on the MB read per second per database times the number of databases in a storage configuration. ESRP currently reports two metrics for database backups the first used in our calculation above is the backup throughput on a database basis and the second is backup throughput on a server basis. I find neither of these that useful from a storage system perspective so we have calculated a new metric for our ESRP analysis which represents the total Exchange database backup per storage system.

I find three submissions (#1, #3 & #8 above) for the same storage system (HDS USP-V) somewhat unusual in any top 10 chart and as such, provides a unique opportunity to understand how to optimize storage for Exchange 2010.

For example, the first thing I noticed when looking at the details behind the above chart is that disk speed doesn’t speed up database throughput. The #1, #3 and #8 submissions above (HDS USP-V using Dynamic or thin provisioning) had 7200rpm, 15Krpm and 7200rpm disks respectively with 512 disk each.

So what were the significant differences between the USP-V submissions (#1, #3 and #8) aside from mailbox counts and disk speed:

Mailboxes per server differed from 7000 to 6000 to 4700 respectively, with the top 10 median = 7500
Mailboxes per database differed from 583 to 1500 to 392, with the top 10 median = 604
Number of databases per host (Exchange server) differed from 12 to 4 to 12, with the top 10 median = 12
Disk size differed from 2TB to 600GB to 2TB, with the top 10 median = 2TB
Mailbox size differed from 1GB to 1GB to 3GB, with the top 10 median = 1.0 GB
% storage capacity used by Exchange databases differed from 27.4% to 80.0% to 55.1%, with the top 10 median = 60.9%

If I had to guess, the reason the HDS USP-V system with faster disks didn’t backup as well as the #1 system is that its mailbox databases spanned multiple physical disks. For instance, in the case of the (#3) 15Krpm/600GB FC disk system it took at least 3 disks to hold a 1.5TB mailbox database. For the #1 performing 7200rpm/2TB SATA disk system, a single disk could hold almost 4-583GB databases on a single disk. The slowest performer (#8) also with 7200rpm/2TB SATA disks could hold at most 1-1.2TB mailbox database per disk.

One other thing that might be a factor between the #1 and #3 submissions is that the data being backed up per host was significantly different. Specifically for a host in the #1 HDS USP-V solution they only backed up ~4TB but for a host in the #3 submission they had to backup ~9TB. However, this doesn’t help explain the #8 solution, which only had to backup 5.5TB per host.

How thin provisioning and average space utilization might have messed all this up is another question entirely. RAID 10 was used for all the USP-V configurations, with a 2d+2d disk configuration per RAID group. The LDEV configuration in the RAID groups was pretty different, i.e., for #1 & #8 there were two LDEVs one 2.99TB and the other .58TB whereas for the #3 there was one LDEV of 1.05TB. These LDEVs were then added to Dynamic Provisioning pools for database and log files. (There might be something in how the LDEVs were mapped to V-VOL groups but I can’t seem to figure it out.)

Probably something else I might be missing here but I believe a detailed study of these three HDS USP-V systems ESRP performance would illustrate some principles on how to accelerate Exchange storage performance.

I suppose the obvious points to come away with here are to keep your Exchange databases smaller than your physical disk sizes and don’t overburden your Exchange servers.

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The full ESRP performance report went out to our newsletter subscriber’s this past January. A copy of the full report will be up on the dispatches page of our website sometime next month (if all goes well). However, you can get the full ESRP performance analysis now and subscribe to future newsletters by just sending us an email or using the signup form above right.

For a more extensive discussion of block or SAN storage performance covering SPC-1&-2 (top 30) and ESRP (top 20) results please consider purchasing SCI’s SAN Storage Buying Guide available on our website.

As always, we welcome any suggestions on how to improve our analysis of ESRP results or any of our other storage performance analyses.

Comments?

ESRP v3 (Exchange 2010) log playback results, 1Kmbox&under – chart-of-the-month

Posted on January 12, 2012December 12, 2012 by Ray in Block Storage, ESRP, ESRPv3/Exchange 2010, Storage performance, System effectiveness

(SCIESRP111029-003) (c) 2011 Silverton Consulting, All Rights Reserved

The above chart is from our last Exchange [2010] Solution Review Program (ESRP) performance dispatch released in our October newsletter (sign-up upper right). The 1K mailbox and under category for ESRP represents Exchange storage solutions for SMB data centers.

As one can see from the above the NetApp FAS2040 has done well but an almost matching result came in from the HP P2000 G3 MSA system. What’s not obvious here is that the FAS2040 had 8 disks and the P2000 had 78 so there was quite a difference in the spindle counts. The #3&4 runs from EMC VNXe3100 also posted respectable results (within 1sec of top performer) and only had 5 and 7 disks respectively, so they were much more inline with the FAS2040 run. The median number of drives for this category is 8 drives which probably makes sense for SMB storage solutions.

Why log playback

I have come to prefer a few metrics in the Exchange 2010 arena that seem to me to capture a larger part of the information available from an ESRP report. The Log Playback metric is one of them that seems to me to fit the bill nicely. Specifically:

It doesn’t depend on the Jetstress IO/rate parameter that impacts the database transfers per second rate. The log playback is just the average time it takes to playback a 1MB log file against a database.
It is probably a clear indicator of how well a storage system (configured matching the ESRP) can support DAG log processing.

In addition, I believe Log Playback is a great stand-in for any randomized database transaction processing. Now I know that Exchange is not necessarily a pure relational database but it does have a significant component of indexes, tables, and sequentiality to it.

My problem is that there doesn’t seem to be any other real database performance benchmark out there for storage. I know that TPC has a number of benchmarks tailored to database transaction activity but these seem to be more a measure of the database server than the storage. SPC-2 has some database oriented queries but it’s generally focused on through put and doesn’t really represent randomized database activity and for other reasons it’s not as highly used as SPC-1 or ESRP so there is not as much data to report on.

That leaves ESRP. For whatever reason (probably the popularity of Exchange), almost everyone submits for ESRP. Which makes it ripe for product comparisons.

Also, there are a number of other good metrics in ESRP results that I feel have general applicability outside Exchange as well. I will be reporting on them in future posts.

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Comments?

Sorry, I haven’t been keeping up with our chart-of-the-month posts, but I promise to do better in the future. I plan to be back in synch with our newsletter dispatches before month end.

The full ESRP performance report for the 1K and under mailbox category went out to our newsletter subscriber’s last October. A copy of the full report will be up on the dispatches page of our website sometime this month (if all goes well). However, you can get performance information now and subscribe to future newsletters to receive these reports even earlier by just sending us an email or using the signup form above right.

For a more extensive discussion of block storage performance in ESRP (top 20) and SPC-1&-2 (top 30) results please consider purchasing our recently updated SAN Storage Buying Guide available on our website.

As always, we welcome any suggestions on how to improve our analysis of ESRP results or any of our other storage system performance discussions.

Latest Microsoft ESRP v3 (Exchange 2010) 1K to 5K mailbox performance results – chart of the month

Posted on August 25, 2011October 8, 2012 by Ray in Block Storage, Disk storage, ESRP, ESRPv3/Exchange 2010, Ethernet, FC, Storage Backup, Storage performance, System effectiveness

SCIESRP110726-004 (c) 2011 Silverton Consulting, All Rights Reserved

Microsoft specifies two different metrics on sequential read rates for database backup activity in their Exchange Solution Reviewed Program (ESRP) reports

MB read/sec per database
MB read/sec total per server

Our problem with these metrics is that they don’t say much about the storage systems performance. Some ESRP submissions could have a single database while others can have 100s of databases. And the same thing applies to servers, although 20 servers seems to be about the max we have seen. So as one can see the MB/s/DB or MB/s/server can vary all over the place depending on the Exchange configuration that one uses, even for the same exact storage system.

In the above chart, we have attempted to move beyond some of these problems and use the information supplied in the ESRP reports to aggregate DB backups across all databases. As such, we have derived a new metric called “total database backup”. (Pretty simple actually just multiply the MB/s/DB times the number of databases in the Exchange configuration).

A couple of problems with our approach.

Current ESRP reports typically utilize a shadow storage system and shadow Exchange servers which host 50% of the databases and email activity. So what I am showing for those ESRP reports is what two storage systems can accomplish not one.
Another potential way to get the same result would be to use the number of servers times the MB/sec/server metric. (But try as I might these two approaches didn’t work to get the same answer so I am using the computation above – must be the way I am recording the number of [shadow] servers).
Although ESRP reports the average MB/sec/database to backup a single database it’s not clear that these measurements were taken while backing up all active databases at the same time, especially for those submissions with 100s of databases.

Probably the last is the most problematic critique to our new measure but may not be that harmful for smaller configurations. Nonetheless, we produced the above chart and published it in our last months review of ESRP results for the 1001 to 5000 mailbox category.

One item we discussed in our report was that numbers of disk drives didn’t seem to correlate well with high positions on this chart. The number ten position (Fujitsu ETERNUS JX40) used over 140 disks, the number two position (Dell PowerEdge R510) had only 12 disk drives, and the number one solution (HP E5700) consisted of 56 drives, close to the average for this category.

One striking finding using this measure is that performance varies considerably from the top providing over 1600 MB/sec of database backup to the lowest of the group providing only ~800 MB/sec of backup performance. What with Exchange 2010 and lagged DAGs, some people feel that backup activity is no longer needed but we would disagree. We continue to believe that taking backups of Exchange data still makes a whole lot of sense and shouldn’t go away, ever.

It’s our hope that this or some similar follow-on metric will remove some of the Exchange configuration parameters from confounding ESRP reported storage system performance results. We realize that this quixotic quest may never be entirely successful nevertheless we perform this duty in the hope that it will benefit today and future storage performance analysts everywhere.

Comments?

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The full ESRP report went out to our newsletter subscribers last month. A copy of the full report will be up on the dispatches page of our website later next month. However, you can get this information now and subscribe to future newsletters to receive these reports even earlier by just emailing us at SubscribeNews@SilvertonConsulting.com?Subject=Subscribe_to_NewsletterR or using the signup form above and to the right.

As always, we welcome any suggestions on how to improve our analysis of ESRP or any of our other storage system performance discussions.

New file system capacity tool – Microsoft’s FSCT

Posted on April 13, 2011 by Ray in Ethernet, File Storage, Networking, Storage, Storage performance, System effectiveness

Filing System by BinaryApe (cc) (from Flickr)

Jose Barreto blogged about a recent report Microsoft did on File Server Capacity Tool (FSCT) results (blog here, report here). As you may know FSCT is a free tool released in September of 2009, available from Microsoft that verifies a SMB (CIFS) and/or SMB2 storage server configuration.

The FSCT can be used by anyone to verify that a SMB/SMB2 file server configuration can adequately support a particular number of users, doing typical Microsoft Office/Window’s Explorer work with home folders.

Jetstress for SMB file systems?

FSCT reminds me a little of Microsoft’s Jetstress tool used in the Exchange Solution Review Program (ESRP) which I have discussed extensively in prior blog posts (search my blog) and other reports (search my website). Essentially, FSCT has a simulated “home folder” workload which can be dialed up or down by the number of users selected. As such, it can be used to validate any NAS system which supports SMB/SMB2 or CIFS protocol.

Both Jetstress and FSCT are capacity verification tools. However, I look at all such tools as a way of measuring system performance for a solution environment and FSCT is no exception.

Microsoft FSCT results

In Jose’s post on the report he discusses performance for five different storage server configurations running anywhere from 4500 to 23,000 active home directory users, employing white box servers running Windows (Storage) Server 2008 and 2008 R2 with various server hardware and SAS disk configurations.

Network throughput ranged from 114 to 650 MB/sec. Certainly respectable numbers and somewhat orthogonal to the NFS and CIFS throughput operations/second reported by SPECsfs2008. Unclear if FSCT reports activity in an operations/second.

Microsoft ‘s FSCT reports did not specifically state what the throughput was other than at the scenario level. I assume Network throughput that Jose reported was extracted concurrently with the test run from something akin to Perfmon. FSCT seems to only report performance or throughput as the number of home folder scenarios sustainable per second and the number of users. Perhaps there is an easy way to convert user scenarios to network throughput?

While the results for the file server runs looks interesting, I always want more. For whatever reason, I have lately become enamored with ESRPs log playback results (see my latest ESRP blog post) and it’s not clear whether FSCT reports anything similar to this. Something like file server simulated backup performance would suffice from my perspective.

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Despite that, another performance tool is always of interest and I am sure my readers will want to take a look as well. The current FSCT tester can be downloaded here.

Not sure whether Microsoft will be posting vendor results for FSCT similar to what they do for Jetstress via ESRP but that would be a great next step. Getting the vendors onboard is another problem entirely. SPECsfs2008 took almost a year to get the first 12 (NFS) submissions and today, almost 9 months later there are still only ~40 NFS and ~20 CIFS submissions.

Comments?

Recent ESRP v3.0 (Exchange 2010) performance results – chart of the month

Posted on February 22, 2011October 8, 2012 by Ray in Block Storage, ESRP, ESRPv3/Exchange 2010, Storage, Storage performance

SCIESRP110127-003 (c) 2011 Silverton Consulting, Inc., All Rights Reserved

We return to our monthly examination of storage performance, and this month’s topic is Exchange 2010 performance comparing results from the latest ESRP v3.0 (Exchange Solution Review Program). This latest batch is for the 1K-and-under mailbox category and the log playback chart above represents the time it takes to process a 1MB log file and apply this to the mailbox database(s). Data for this report is taken from Microsoft’s ESRP v3.0 website published results and this chart is from our latest storage intelligence performance dispatch sent out in our free monthly newsletter.

Smaller is better on the log playback chart. As one can see it takes just under 2.4 seconds for the EMC Celerra NX4 to process a 1MB log file whereas it takes over 7.5 seconds on an EMC Iomega IX12-300r storage subsystem. To provide some perspective in the next larger category, for storage supporting from 1K-to-5K mailboxes, the top 10 log playback times range from ~0.3 to ~4.5 seconds and as such, the Celerra NX4 system and the other top four subsystems here would be in the top 10 log playback times for that category as well.

Why log playback

I have come to believe that log playback is an important metric in Exchange performance, for mainly one reason, it’s harder to game using Jetstress paramaterization. For instance, with Jetstress one must specify how much IO activity is generated on a per mailbox basis, thus generating more or less requests for email database storage. Such specifications will easily confound storage performance metrics such as database accesses/second when comparing storage. But with log playback, that parameter is immaterial and every system has the same 1MB sized log file to process as fast as passible, i.e., it has to be read and applied to the configured Exchange database(s).

One can certainly still use a higher performing storage system, and/or throw SSD, more drives or more cache at the problem to gain better storage performance but that also works for any other ESRP performance metric. But with log playback, Jetstress parameters are significantly less of a determinant of storage performance.

In the past I have favored database access latency charts for posts on Microsoft Exchange performance but there appears to be much disagreement as to the efficacy of that metric in comparing storage performance (e.g., see the 30+ comments on one previous ESRP post). I still feel that latency is an important metric and one that doesn’t highly depend on Jetstress IO/sec/mailbox parameter but log playback is even more immune to that parm and so, should be less disputable.

Where are all the other subsystems?

You may notice that there are less than 10 subsystems on the chart. These six are the only subsystems that have published results in this 1K-and-under mailbox category. One hopes that the next time we review this category there will be more subsystem submissions available to discuss here. Please understand, ESRP v3.0 is only a little over a year old when our briefing came out.

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The full performance dispatch will be up on our website after month end but if one needs to see it sooner, please sign up for our free monthly newsletter (see subscription widget, above right) or subscribe by email and we’ll send you the current issue along with download instructions for this and other reports. Also, if you need an even more in-depth analysis of block storage performance please consider purchasing SCI’s SAN StorInt Briefing also available from our website.

As always, we welcome any constructive suggestions on how to improve any of our storage performance analyses.

Comments?

Latest ESRPv3 (Exchange 2010) results analysis for 1K-to-5Kmailboxes – chart of the month

Posted on November 23, 2010October 8, 2012 by Ray in Block Storage, Disk storage, ESRP, ESRPv3/Exchange 2010, Storage, Storage performance

(c) 2010 Silverton Consulting, Inc., All Rights Reserved

The chart is from SCI’s October newsletter/performance dispatch on Exchange 2010 Solution Reviewed Program (ESRP v3.0) and shows the mailbox database access latencies for read, write and log write. For this report we are covering solutions supporting from 1001 up to 5000 mailboxes (1K-to-5Kmbx), larger and (a few) smaller configurations have been covered in previous performance dispatches. On latency charts like this – lower is better.

We like this chart because in our view this represents a reasonable measure of email user experience. As users read and create new emails they are actually reading Exchange databases and writing database and logs. Database and log latencies should show up as longer or shorter delays in these activities. (Ok, not exactly true, email client and Exchange server IO aren’t the same thing. But ultimately every email sent has to be written to an Exchange database and log sometime and every new email read-in has to come from an Exchange database as well).

A couple of caveats are in order for this chart.

Xiotech’s top run (#1) did not use database redundancy or DAGs (Database Availability Groups) in their ESRPv3 run. Their feeling is that this technology is fairly new and it will take some time before it’s widely adopted.
There is quite the mix of SAS (#2,3,6,7,9&10), FC (#1,5&8) and iSCSI (#4) connected storage in this mailbox range. Some would say that SAS connected storage should have an advantage here but that’s not obvious from the rankings.
Vendors get to select the workload intensity for any ESRPv3/Jetstress run, e.g. the solutions shown here used between 0.15 IO/sec/mailbox (#9&10) and 0.36 IO/sec/mailbox (#1). IO intensity is just one of the myriad of Jetstress tweakable parameters that make analyzing ESRP so challenging. Normally this would only matter with database and log access counts but heavier workloads can also impact latencies as well.

Wide variance between read and write latencies

The other thing of interest in this chart is the interesting span between read latencies and write (database and log) latencies for the same solution. Take the #10 Dell PowerEdge system for example. It showed a database read latency of ~18msec. but a database write latency of ~0.4msec. Why?

It turns out this Dell system had only 6 disk drives (2TB/7200 RPM). So few disk drives don’t seem adequate to support the read workload and as a result, show up poorly in database read latencies. However, write activity can mostly be masked with cache until it fills up, forcing write delays. With only 1100 mailboxes and 0.15 IOs/sec/mailbox, the write workload apparent fits in cache well enough to be destaged over time, without delaying ongoing write activity. Similar results appear for the other Dell PowerEdge (#6) and the HP Smart Array (#7) which had 12-2TB/7200 RPM and 24-932GB/7200 RPM drives respectively.

On the other hand, Xiotech’s #1 position had 20-360GB/15Krpm drives and EMC’s Celerra #4 run had 15-400GB/10Krpm drives, both of which were able to sustain a more balanced performance across reads and writes (database and logs). For Xiotech’s #5 run they used 40-500GB/10Krpm drives.

It seems there is a direct correlation between drive speed and read database latencies. Most of the systems in the bottom half of this chart have 7200 RPM drives (except for #8, HP StorageWorks MSA) and the top 3 all had 15Krpm drives. However, write latencies don’t seem to be as affected by drive speed and have more to do with the balance between workload, cache size and effective destaging.

The other thing that’s apparent from this chart is that SAS connected storage continues to be an effective solution for this range of Exchange configurations, following a trend first shown in ESRP v2 (Exchange 2007) results. We reported on this in our January ESRPv2 analysis dispatch for this year .

The full dispatch will be up on our website in a couple of weeks but if you are interested in seeing it sooner just sign up for our free newsletter (see upper right) or subscribe by email and we will send you the current issue with download instructions for this and other reports.

As mentioned previously ESRP/Jetstress results are difficult to compare/analyze and we continue to welcome any constructive suggestions on how to improve.