0
votes
2answers
76 views

Unreasonable performance expectations for RAID 0 performance?

This is my first time building a machine with a hardware RAID card. We bought a Dell T620 with the H710P RAID controller (1GB NV Cache), a 160GB Solid State Drive (SATA Read Intensive MLC 3Gbps), and ...
5
votes
4answers
671 views

How do I configure RAID 5, especially stripe size, with 24 x 1.2 TB drives for CentOS 6?

For a Dell R920 with 24 x 1.2TB disks (and 1TB RAM), I'm looking to set up a RAID 5 configuration for fast IO. The server will be used to host KVM VMs that will be reading/writing files of all sizes, ...
10
votes
2answers
774 views

Why is my RAID1 read access slower than write access?

I have done some simple performance tests and it seems that reading from my RAID1 is slower than writing: root@dss0:~# for i in 1 2 3; do dd if=/dev/zero of=/dev/sda bs=1048576 count=131072; done ...
3
votes
1answer
150 views

Filesystem performance degraded during RAID rebuilding

So quick question - our RAID6 array is currently rebuilding and there is a VERY noticeable filesystem performance hit (home directories are NFS mounted on the array). I'd sort of expect that, given ...
2
votes
4answers
860 views

LSI RAID: Write cache policy affects read performance?

I have a server with a LSI MegaRAID SAS 9260-4i controller, RAID-5 with 3 x 2 TB disks. I did some performance testing (with iozone3) and the numbers show clearly that the write cache policy affects ...
0
votes
3answers
220 views

Does software RAID-0 really improve performance?

I am going to lease a server and I have two options, SATA or SSD, I decided to save the money and go for the SATA option. But I do not need all that storage they are giving me! So I thought MAYBE I ...
2
votes
0answers
126 views

mdadm raid10 or nfs performance issues?

I have a fresh mdadm RAID10 device which is healthy, built from 4 x 7200rpm SATA 3 drives: # cat /proc/mdstat Personalities : [raid10] [raid1] md2 : active raid10 sdc3[5] sda3[4] sdb3[1] sdd3[3] ...
0
votes
0answers
70 views

Boot disk with VMFS read/write driver

I want to rule out the ESXi kernel being the cause for my terrible 15MB/s write speed on the local VMFS datastore. I am using a Dell PERC H710 RAID controller, and would like to boot from a boot disk ...
1
vote
1answer
837 views

Slow Write Speed on ESXi host

I have an ESXi 5.0 free host with an internal datastore of 7.2K 5 disk RAID 5 using a PERC 710 mini RAID controller in a Dell Poweredge R620 Server with 32GB Ram and a 12 Core Xeon. I seem to get ...
0
votes
1answer
1k views

Upgrading a PERC h310 to a PERC H710 mini RAID controller on a Dell R620

I have an ESXi 5.0 Free license host using an internal Datastore (RAID 5, 5 Disk) that was configured with a Dell PERC h310 RAID controller. The disk performance was very poor, so I upgraded to the ...
4
votes
1answer
4k views

Poor Disk Performance on VMs; Host using PERC H310 RAID 5

I have a Dell R620 running 5 500GB 7.2K RPM SATA 3Gbps 2.5in Hot-plug Hard Drives in a PERC H310 controller (which I am beginning to regret buying). I am getting awful read/write speeds on Linux ...
1
vote
3answers
487 views

IBM SR-BR10i RAID Controller too slow with VMware ESXi

I'm transferring a virtual machine from one ESXi host to another using SSH on both ESXi Servers. But it's painful slow, it's a massive 750GB .vmdk disk image, the VM is stopped (with downtime) and ...
1
vote
1answer
1k views

Linux RAID5 Optimal Chunk Size

I bring up, yet again, the ever-present question of how to best optimize disk structures. In my organization, we have a 14TB Linux software RAID array dedicated to storing backups made using Symantec ...
2
votes
1answer
52 views

Benchmark individual drives in RAID5

I'm running a server with 3 RAID5 arrays through an ARECA 1880i coupled with a HP-SAS Expander. After experiencing a massive degradation in performance lately, I want to benchmark the drives ...
0
votes
1answer
398 views

Which alternative is most performant (raid, ssd, 15k rpm disks)

I'm looking at the DELL PowerEdge™ R720 from Hetzner. This server has a Dell PERC H710 8 Port SAS/SATA 6GBit/s raid controller. I have the choice between: 3 x 600GB SSD (MLC SATA 3Gb/sec) 6 x ...
0
votes
3answers
1k views

Very poor performance on LUKS/LVM/RAID combination under Debian Squeeze

I have the following issue: I have an encrypted partition on a lvm on a plain partition on the hd. Now I craeted a RAID array to increase the performance. That means, that I have the following stack: ...
0
votes
2answers
575 views

High %wa in top on KVM host

I have a server running several KVM virtualized guests that's reporting a high %wa in top. The server hardware is as follows: 4x2TB in hardware RAID10 64GB RAM Dual E5-2620 top output % top - ...
1
vote
2answers
8k views

VMware ESXi 5 Slow performance, hundreds of I/O latency errors. [closed]

We have a standalone ESXi5 Server with the follow hardware specs: - Supermicro X8DTL - Intel Xeon(R) CPU E5506 2.13GHz - 25G Ram - 1TB HD (mirrored RAID, local SATA) We have around 17 VM's running, ...
1
vote
1answer
549 views

How to change the scheduler of a RAID 5 device?

I've created a RAID 5 device block by combining 4 HDDs. The name of my device is md1. But the /sys/block/md1/queue/scheduler file outputs "none" on doing cat. And also after editing it using vim ...
1
vote
1answer
87 views

RAID: is it enough to have n+1 disks in a RAID6 array to match performance of a n disks RAID5 array? [closed]

As far as I know, RAID-6 has an even worse penalty on writes than its cousin RAID-5. But we also know that we can get more performance out of a typical RAID array by having more spindles in it. But ...
0
votes
0answers
185 views

RAID10 (4x SSD) system is super slow for 'dd' and 'find' commands

I have configured two servers each with 32 GByte RAM, 2x Xeon 2.4 GHz, 4x 480 GByte Intel SSD on a LSI MegaRAID SAS 9261-8i controller. They should be identical, however one of them has a very poor ...
0
votes
2answers
268 views

Pervasive SQL Server configuration

Our Sage 50 application takes a long time to load. We recently moved it to a newer server and the speed has improved but opening the application and accessing data is still time consuming and not ...
3
votes
1answer
674 views

Windows 8 x64 with VMWare Workstation or inside ESXi [closed]

I need to run several virtual machines on a core i7-920 box with 12GB or RAM and a 256GB SSD to host the VMs. It also has a Highpoint RocketRaid 2720SGL RAID controller with a 12TB RAID 5 array. I ...
-3
votes
1answer
48 views

number of disks for RAID config vs. effect on performance? [closed]

I was wondering how the number of disks used for RAID configuration affects performance? I know that it takes longer to rebuild data, but are there any other performance areas affected??
-3
votes
1answer
198 views

Raid 1/0 SSD vs 2 x non-Raid SSD [closed]

I have a question about speed performance with two separate SSD drives comparing them to RAID mirror array. I do not like idea to setup RAID 0 with 2 x SSD drives because of high risk of data loss, ...
1
vote
3answers
2k views

RAID10 without write-back cache = horrible write performance?

I have just provisioned a dedicated server on singlehop. I'm running it through some tests to know what to expect performance-wise. On the I/O side (with 4 1TB disks in RAID 10) I get: write-cache ...
2
votes
1answer
250 views

How to get started troubleshooting Linux mdadm raid10 write performance?

Using Linux mdadm, I've setup a six disk raid10,f2 array. I'm using 7200RPM SATA drives. The biggest load I am worried about is recording four streams of live video (worst case of 20Mbits each, final ...
2
votes
2answers
217 views

How to figure out disks performance in Xen?

So, I have a Dell R710 with PERC 6/i Integrated and 6 450Gb Seagate 15k SAS disks in RAID10, I have 30 Xen vps working on it. Now I need to deploy second server with same hardware for same tasks and I ...
2
votes
4answers
414 views

When using RAID10 + BBWC why is it better to separate PostgreSQL data files from OS and transaction logs than to keep them all on the same array?

I've seen the advice everywhere (including here and here): keep your OS partition, DB data files and DB transaction logs on separate discs/arrays. The general recommendation is to use RAID1 for OS, ...
0
votes
1answer
218 views

file read performance degrades as number of files increases

We're observing poor file read IO results that we'd like to better understand. We can use fio to write 100 files with a sustained aggregate throughput of ~700MB/s. When we switch the test to read ...
4
votes
2answers
81 views

LVM Configuration possible?

I have hard discs D1 and D2 which are 140GB each and D3,D4 which are 600GB. I've been reading about the benefits of using LVM and I was thinking about the following configurations. This one would ...
2
votes
2answers
342 views

Decrease in disk performance after partitioning and encryption, is this much of a drop normal?

I have a server that I only have remote access to. Earlier in the week I repartitioned the 2 disk raid as follows: Filesystem Size Used Avail Use% Mounted on /dev/mapper/sda1_crypt ...
2
votes
2answers
220 views

16tb raid6 + lvm, to partition or not to partition?

So I have a 16tb raid6 on one of a new batch of machines I am setting up. I will be using LVM on top of this and am wondering if there are any compelling reasons to break the raid up into partitions ...
1
vote
3answers
1k views

How to use 2 SSD disks for best performace?

I am going to format 2 120GB Intel 320 SSD to be used for a high traffic Drupal server. The server had Xeon E1270 CPU and 32GB RAM. I'm using Debian Squeeze 64 bit. Here are my questions: What ...
2
votes
1answer
1k views

dd oflag=direct 5x fast

I have Centos 6.2 in server with this specs: 2xCPU 16 Core AMD Opteron 6282 SE 64GB RAM Raid controller H700 1GB cache NV - 2HD 74GB SAS 15Krpm RAID1 stripe 16k (OS Centos 6.2) sda - 4HD 146GB SAS ...
2
votes
3answers
1k views

Raid-5 Performance per spindle scaling

So I am stuck in a corner, I have a storage project that is limited to 24 spindles, and requires heavy random Write (the corresponding read side is purely sequential). Needs every bit of space on my ...
0
votes
2answers
788 views

xenserver 5.6 on on raid 10 array

We've always had performance issues with our Xenserver 5.6 and ive asked a question here about it and still didnt manage to get it resolved ...
1
vote
3answers
252 views

8MB/10K RAID5 vs 2x 64MB/7.2K RAID10

I'm looking at replacing an old file server sharing a single RAID5 volume powered by 6 10K rpm disks with 8MB caches. The replacement will be 2 RAID10 volumes of 4 disks each. The new disks have 64MB ...
26
votes
9answers
5k views

To improve SQL performance, why not just put lots of RAM rather than having faster hard disks?

People keep telling me that in order to improve an SQL server's performance, buy the fastest hard disks possible with RAID 5, etc. So I was thinking, instead of spending all the money for ...
2
votes
1answer
428 views

RAID 10 or RAID 1 x 2 for Hyper-V with AD, EXCHANGE on Windows 2008 R2

We have 2 servers which have 6 SATA 7200 disks inside (each). We want to configure both servers so that they will have Window Server 2008 R2 Enterprise installed and on top of it Exchange 2010 x2 (for ...
3
votes
3answers
418 views

Getting more database performance - postgresql

There is a django "web application" (from hell) we are hosting on a dedicated server. After some benchmarking I found that the "Application" is amazingly bad at database operations (refactoring is not ...
0
votes
4answers
703 views

SQL Server: One 12-drive RAID-10 array or 2 arrays of 8-drives and 4-drives

Setting up a box for SQL Server 2008, which would give the best performance (heavy OLTP)? The more drives in a RAID-10 array the better performance, but will losing 4 drives to dedicate them to the ...
-2
votes
3answers
87 views

Are Superfast HDDs necessary outside a SAN? [closed]

Does it make sense to have 15k HDDs / fast raid configurations in a server connected to Gigabit Ethernet. Surely the HDDs would only become the bottleneck when you get into the realms of Fiberchannel ...
5
votes
7answers
2k views

setup lowcost image storage server with 24x SSD array to get high IOPS?

I want to build let's name it a lowcost Ra*san which would host for our social site the images (many millions) we have 5 sizes of every photo with 3 KB, 7 KB, 15 KB, 25 KB and 80 KB per Image. My ...
2
votes
1answer
271 views

FreeBSD vinum striped (RAID0) volume - performance issues

I've experimented with different striped volumes in vinum under FreeBSD 8.2-release. I have current hardware (Intel i5 processor, adequate MB and 8GB RAM). My test-setup consists of 2 or 4 disks in a ...
2
votes
1answer
380 views

Do these results look right for 4xSATA in RAID 10? The writes are faster than the reads?

Do these results look right for a RAID-10 consisting of 4x1TB Samsung F3 SATA drives connected via a Dell Precision T3500's integrated RAID controller (which I believe is an Intel-based "FakeRAID")? ...
7
votes
1answer
330 views

RAID with 4 drives offers very minimal speed improvement

Setup 1.5TB x 8 on a SANS Digital enclosure configured into two sets of 4 drives and connected to a Windows Server 2003 computer over eSATA. They are all identical Seagate Barracuda ST31500341AS ...
1
vote
4answers
408 views

RAID setup for high speed reading

We are looking to build a realtime playback machine using Linux and a RAID (5 or 10) setup. The current setup looks like: 12GB memory 5 x 7200rpm drive (software raid) centOS 6 (Kernel Linux ...
1
vote
2answers
1k views

Software RAID 5 vs RAID 6 performance

I had an original software RAID 5 setup under Ubuntu 10.04.03, 3 devices, 64k chunk. Performance was acceptable: # 4GB write dd if=/dev/zero of=ddfile.big bs=1MB count=4k 4095290816 bytes (4.1 GB) ...
1
vote
1answer
167 views

RAID config. for a Heavily Used File Server

I'm building a new file server to replace an existing server. The current workload is about 50 connections that are heavily reading and writing files all day long. It is about 50/50 read to write. ...