Tagged Questions
The disk-performance tag has no wiki summary.
-2
votes
0answers
36 views
ReadyBoost or RSTv10.5 to boost my HDD read time using an SSD? [closed]
I am trying to figure out which of the two following scenarios would perform faster. The system has a 500Gb disk, 8Gb Ddr3 Ram and i7 2600, Win7 x64:
Scenario - ReadyBoost
SSD drive in sata3 with ...
2
votes
3answers
52 views
Processes in uninterruptable sleep killing server
I have a opensuse 11 64 bit server with some issues I'm not sure how to solve. I'm getting hundreds of these in the porocess list:
4 0 3105 1 20 0 55420 3488 646312 Sl ? 0:02 ...
-2
votes
4answers
82 views
what are all the common factors affecting VM performance? [closed]
Recently we faced a performance problem in our ESXi 4.1 hosted in Dell R710 server.
I verified RAM and it was 48 GB. I checked the CPU it was quadcore. Finally i came to know that the server had only ...
0
votes
5answers
167 views
What are the more reliable SSDs to use in an enterprise environment?
We all know SSDs are fast... but aren't all that great when it comes to any computer that writes to disk many times in any given minute.
Are there any SSDs that are suited for an enterprise ...
0
votes
3answers
38 views
Resource monitor and how to spot if you have disk I/O problems?
I have an application server which runs pervasive SQL and app using it.
Last weeks the users are complaining about poor performace of the app and I suspect disk I/O problems because CPU and RAM ...
2
votes
3answers
136 views
Large disk queue length
A few days ago disk on my server started to have large queue length:
I've changed controller battary recently, HP configuration utility was saying the battery is bad, but after changing the battery ...
1
vote
1answer
111 views
Poor hard drive performance
I have nearly two identical servers, the only difference between the
two is the version of Linux and the Hard Drive. Server 1 had (what I
think) is a better drive, therefore the performance should be ...
0
votes
1answer
82 views
Disk warning 51 on Windows 2008 x64 Standard R1
I keep getting a disk warning 51 message in the system log every few months. It eventually causes the server to crash (killing all my network services), forcing me to do a hard reboot.
Full error ...
0
votes
4answers
97 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 ...
0
votes
0answers
51 views
Server freeze (Disk I/O possibly)
I have a Windows Server 2008 machine that is resyncing disks after a powerloss. The issue is that the system becomes unresponsive after about 10 minutes. We've checked with resource monitor and found ...
1
vote
0answers
37 views
Benchmarking a file server
I'm working on building a new file server... a simple Windows Server box with a few terabytes of disk space to share on the LAN. Pain for current hard drive prices aside :( -- I would like to get ...
3
votes
1answer
98 views
Poor NFS performance when sequentially reading large files
I have an NFS3 server with multiple clients. Each client is sequentially reading a different large file, and performance is very poor.
Here is what I am observing in iostat on the server for the disk ...
0
votes
0answers
16 views
How do I get AvgDiskSecPerWrite to return the same value as the object in perfmon instead of 0?
I am trying to query WMI to get the value for AvgDiskSecPerWrite from Win32_PerfFormattedData_PerfDisk_PhysicalDisk using WQL with the following query
SELECT AvgDiskSecPerWrite FROM ...
0
votes
0answers
26 views
compress to another disk, then move back slower than operating on single disk
Could you help me understand performance differences, I've experienced compressing some data?
The story is that I compress various files (20kB-600MB) in 2e20 chunks from one LUN to another.
Then I ...
1
vote
0answers
234 views
High disk I/O activity in CentOS server
I have about 16 websites in a CentOS dedicated, and I am having some problems on high traffic hours, it seems to be a high disk I/O activity causing a general slowdown.
I've installed atop and this ...
1
vote
1answer
39 views
How is the average seek of disk estimated given a function to move head to n track
How is the average seek time of disk calculated if a function f(x) is given as an estimate of time to move head of disk to n tracks?
0
votes
2answers
150 views
How to remove swap partitions from RAID 1 Array on Ubuntu?
Can anyone point in the right direction on how to remove SWAP out of a RAID1 configuration on Ubuntu 10.04 server? According to the Ubuntu Advanced installation guide, here, it said to add swap to the ...
1
vote
0answers
99 views
Apache's htcacheclean doesn't scale: How to tame a huge Apache disk_cache?
We have an Apache setup with a huge disk_cache (>500.000 entries, >50 GB disk space used).
The cache grows by 16 GB every day.
My problem is that the cache seems to be growing nearly as fast as it's ...
1
vote
1answer
230 views
fio config to measure IOPS against provider SLA
So a provider has given us 500 IOPS/TB as their SLA standards for disk performance in a VMWare & RAID5-SAN environment. This is apparently measured with:
16kB average transfer block size
3:1 ...
-1
votes
2answers
77 views
How to perform Server Performance Audit [closed]
Here is the situation. I am the CIO in my work place. The guy on the management team that get to take decision regarding Techy things. I dont do actual development, but we have an IT service provider ...
0
votes
2answers
126 views
md-RAID5 - How fast should it be or where is the bottleneck?
I set up a new server with a LUKS encrypted RAID5. On the former server, the bottleneck was definitely the CPU, as it was a 7y old single core and the load went up to 100%.
Now it is different. I ...
9
votes
2answers
268 views
How does Linux handle concurrent disk IO?
When a Linux server is serving many concurrent requests to read many different files, does it:
Seek to File_1, read the entire file, then seek to File_2, read the entire file, then seek to File_3, ...
7
votes
1answer
213 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 ...
0
votes
1answer
44 views
MS Server 2008 NLB: Writing on Harddisk
I'm in a confusing situation right now: I have 2 MS Server 2008, hosting a WCF-Webservice which is basically reading data from an SQL-Server and forwarding it to the client.
We use NLB to loadbalance ...
0
votes
1answer
115 views
Appropriate Linux (ubuntu 10.04) FS type for rapid FS management many small files and directories [closed]
Possible Duplicate:
Linux's best filesystem to work with 10000's of files without overloading the system I/O
I have an 240gb image store of approximately 1.5 million entries. About ...
4
votes
4answers
440 views
PERC 6/i RAID on Dell R710: Slow disk… RAID10 on single controller?
There are multiple questions here - but it starts with this: we've a Dell PowerEdge R710 with a PERC 6/i RAID controller (or controllers) in a RAID10 configuration.
The system is running Ubuntu ...
1
vote
1answer
91 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. ...
1
vote
1answer
196 views
iotop for Linux kernel 2.6.18
So it has to come to my attention that iotop isn't availalbe for 2.6.18 since it's less than 2.6.20 and requires Python 2.6+. I've done some research and came across this article:
...
0
votes
3answers
340 views
Measure Linux IOPS for a running system
How do I measure IOPS of a running Linux server? I know that the theoretical IOPS of a SATA drive is around 90 and enterprise 10k SAS/FC disk is 180. I want to know how much my running system is using ...
0
votes
2answers
89 views
how to get block sizes larger than 4k in reads from an md raid1 volume
I wanted to setup a raid01 configuration (a raid1 composed of two raid0s) with one of the raid0 volumes having the write-mostly state set so all reads would go to the other (i.e. one is disk, the ...
2
votes
1answer
145 views
Performance testing servers: How to characterize performance?
I need to purchase servers, and need to understand the right way to specify them.
Based on the answers to this question, there are several parameters to take into account:
CPU speed + Number of CPU ...
3
votes
1answer
114 views
Truecrypt - disk stops reading/writing with regular intervals (Ubuntu)
I am running Ubuntu Lucid with a raid0 setup
Intel Xeon X3440 - 4x (2x 2.9GHz)
16GB RAM
I got a 1.9TB truecrypt7.0 file container with AES located in my /home (where raid is).
When testing ...
1
vote
1answer
69 views
Hyper-V limit disk usage of a VM
I'm using Hyper-V on Windows Server 2008 R2. I have one virtual machine that writes constantly to its vhd, using between 60% and 100% of the maximum disk I/O according to Resource Monitor. This ...
1
vote
0answers
109 views
Physical Disk counters not showing up in PerfMon results
I am trying to diagnose some issues for a customer, but i notice that none of the disk related counters show up in my PerfMon results (graph or csv format).
I found this article ...
3
votes
2answers
107 views
Spreading IO load over physical drives/arrays in VirtualBox VMs
We use VMs with snapshots as part of our support and release testing processes, which makes testing patches to client systems convenient (take snapshot, apply changes, test, revert, lather, rinse, ...
0
votes
1answer
144 views
Resource Monitor Disk Usage scale
I'm sure this is going to be very dependent on the harddrives and other hardware that we have in our machine, but I have no idea how to read these graphs.
This graph looks nice and low.
This one ...
4
votes
1answer
230 views
Dual Controller SAN 8x1GBE or 4x10GBE Performance
I'm looking at getting 3 hosts and a SAN set up with iSCSI for a VMware envoroment and have had several companies come to us with suggestions (small team and will need help with implementation). They ...
2
votes
2answers
108 views
Transfer between internal disks slows down for large files
I'm running a Ubuntu Server 11.04 (amd64) on a machine with 1.6Ghz dual-core CPU, 4GB RAM, and 2x250GB 7200 SATA drives (both 3.0Gb/s and newly formatted from a fresh install). When I transfer ...
3
votes
2answers
70 views
Measuring disk seeks under windows
I would like to measure the number of disk seeks that are made by a process under Windows. If I open Task Manager, I can see a column named "I/O - reads". Is this the equivalent of disk seeks? Can I ...
4
votes
3answers
557 views
What KVM disk type to use?
I'm setting up a few KVM virtual guests and I'm debating which disk type to use. I haven't been able to find a good resource online that runs down the pros and cons of each.
Can you help me create a ...
3
votes
1answer
377 views
Very slow write performance on Debian 6.0 (AMD64) with DMCRYPT/LVM/RAID1
I'm seeing very strange performance characteristics on one of my servers. This server is running a simple two-disk software-RAID1 setup with LVM spanning /dev/md0. One of the logical volumes ...
0
votes
1answer
209 views
SAN I/O is horrible
I've been testing a SAN with fibre channel disks and I get 500MBPS Writes 200MBPS sequential reads and about 5MBPS randon reads / 1000 IOps max. Any idea why reads are so much slower? It is a 3PAR SAN ...
1
vote
4answers
467 views
How to reduce mysql disk io?
mysql> explain SELECT *
-> FROM (`items`)
-> WHERE `states` = 'A'
-> ORDER BY `updated_date` desc
-> LIMIT 20520, 40;
...
0
votes
1answer
160 views
What do the output values of dstat command mean when monitoring IO?
I am monitoring the IO and SWAP usage of a process in my backup server. I executed dstat -rs 5 and this was an example output:
--io/total- ----swap---
read writ| used free
92.0 57.3 |3228k 514M
...
3
votes
2answers
770 views
iostat on Solaris with ZFS - why is wait and %w always zero?
We have a busy server, chocking under a high IO load, at least, that's the feeling I have. Output from iostat -xz looks like this:
extended device statistics
device ...
0
votes
1answer
67 views
Disk Cleanup Batch File With Logs
I was wondering if there is a way to create a batch file that will run a Disk Cleanup (on XP and 7 PC's), and have it create a log file on the local PC that will tell me the details, or that it's run.
...
1
vote
2answers
175 views
Does VMDirectPath help disk IOPS performance?
I read the VMDirectPath materials, and they say that it helps the performance on the 10Gbs card case. Sure, if multiple VMs directly access the physical 10GbE card, the VMM bottleneck is avoided with ...
1
vote
3answers
457 views
Poor XFS performance — what's going on?
I recently formatted a 20TB array as XFS. For file transfers < 10G performance is fantastic. However once I exceed 10G disk I/O decays logarithmically. I have the journal on the same disk. When ...
3
votes
7answers
591 views
Windows Server 2008 R2 grinds to a screeching halt during file copy operations
When my Windows Server 2008 R2 machine is performing any large disk operations (copying 10GB files from one drive to another, copying similar file over network, merging HyperV snapshots, compressing ...
2
votes
2answers
201 views
10tb file storage design question on media website
I have a fairly busy media website where MP3 audio files are uploaded by members and streamed / downloaded from 2 Windows servers which are load balanced at the moment...both servers simply mirror ...
