I am currently using areca Raid card with Centos 5 which allows me to configure Raid 6 with SAS drives. But it is really costing a bomb not to say that the lead time in ordering the card is long. Performance wise is fantastic though. Anyone know of any cheaper alternative to areca that can support Centos 5 and Raid 6 SAS Drives?
View 7 RepliesAnyone know what is a suitable SATA Raid card that supports Centos 4.4/4.6? I tried 3ware 9550 it is suppose to support Centos 4.4, but gives a kernel panic instead.
View 13 Replies View RelatedIs Motherboard RAID as good as a dedicated PCI-E card? I am guessing a dedicated card is the best option, though costs more.
We are looking at buying a barebones server from Supermicro. It features an onboard RAID controller which supports RAID 0, 1, 5 & 10 - but for some strange reason it will only support RAID 5 if you use Windows. Here is a link to the page detailing the RAID features.
[url]
We are going to be running Linux, CentOS 5.1, so we will only have the choice of RAID 0, 1 or 10. This isn't an issue, as having RAID 10 on 4x SAS (15k) drives will be fine for speed and stability. What is an issue is would this RAID controller be as fast or reliable compared to a dedicated PCI-E card? If it can only use RAID 5 in windows, does that suggest this controller is too reliant on software? It would be a nightmare to suffer downtime and data loss because the controller couldn't hack it during a drive failure, or one day it decided to bugger up the array when rebooting.
So that leads me to looking at this card, this looks very good for what we need. Are adaptec a reliable brand? I've seen it advertised for £200, which is a good price.
[url]
This card features RAID 5 and 6, would RAID 6 be better than RAID 10 for redundancy, or is it too slow to bother with? Also it seems to have a battery module available for it, what does this achieve? Cos surely if the power dies the hard drives and motherboard can't run off this little battery, or does it just help the controller stay alive long enough with some hard drive information in its memory if the power goes out during a rebuild?
I was building a 1u server a month or so ago to colocate. After screwing up the purchase of the raid card (got a pci 64 or something) its been sitting next to me not doing much. I need to go ahead and find a good raid card and get this colocated,
I have literally spent hours on Newegg, Amazon and Ebay and found nothing that really jumps out at me. When people were helping with the build before, Adaptec was recommended, but the card is now deactivated on newegg so I am looking again.
I was wondering if anyone has had luck with 3ware 9650's in a RAID 10 to help bring down iowait?
I currently have a VPS node that see's spikes in iowait and i'd like to bring it down. I've been considering getting a 9650 in a JBOD setup (so then I don't need to reinstall the whole node) with a battery backup to enable the cache.
My two questions are:
- In JBOD, does the write cache enable at all?
- Would the write cache help bring down the iowait much?
Drive wise we have 4 x 500GB drives in a raid10 (soft for now).
we have some supermicro 6016-MT with 4 x SATA2 Harddrives, and would like to use raid 1/5/10.
On Dell, its very "easy" to find a raid controller, and i have never been worried about this before, but with supermicro im a little confused.
Server: supermicro.com/products/system/1U/6016/SYS-6016T-MT.cfm
I was looking at Adaptec 3405, ( adaptec.com/en-US/support/raid/sas_raid/SAS-3405/ ) but are not sure if this is the right card for this server. Is this overkill or to small a card for a 4 disk 1u server?
About cabling: On Adaptec's site they state
"Cable: one Mini SAS x4 to (4x) SATA fanout cable w/ sideband (2247000-R), 0.5 meter"
But are this cable the correct one for a server like this with backplane and everything, or should i look for a special cable? if so, anyone know what i need to order?
We've got a couple of Dell SC440's that we use for low end stuff. We need one with RAID-1 so after talking with our Dell rep we ordered a 5iR card and the corresponding SATA cables. The cables are kind of funky in that the drive end of the cable has both the SATA and power connector in one "thing". You then plug the SATA power into the back of this (it piggy backs on). Once you have done all that the cover won't fit back on as the power connectors stick about 1/2" in beyond the case.
Anyone out there have a SC440 with RAID so we can compare notes?
I have bought 4 servers with DELL SAS 5/iR.
All is fine but the writes are very slow; I supose it's because write cache not enabled.
I have enable it and make some test and there is a lot of difference:
[url]
I'm worried about enabling it because if the server goes down I think it can cause disk corruption and loose data and maybe the OS. What do you think about that? Data is a priority!
Disks have this technology: Seagate-exclusive IRAW (Idle Read After Write) enhances data
protection by verifying—during drive idle time—that data in thedrive buffer was properly written.
The servers are on a datacenter and have RAID 1 with Cheetah® 15K.5 SAS 3Gb/s 146.8-GB Hard Drive - ST3146855SS
[url]
I'm also VERY worried about the coments about this card:
[url]
Is it true that the raid don't get rebuilded? If it is like this I don't know why I'm running raid.
for a hosting server,many parts of the hardware are all important,
and some part may effect the performance and price,
i just wonder two part,
how can i judge if the raid card and chip is powerful enough to run a hosting server?
Will a Perc 5 raid card work in a non-dell Linux server? These cards can be found for about $100 on eBay, and are much cheaper than the Adaptec cards with similar features and ports.
View 5 Replies View RelatedI'm playing around with different configurations on my box at home and wanted to practice setting up RAID 1 - 2 harddrives. Here is how I set it up during install. It seems to be working fine, but are there any issues with this?
/dev/hda1 /dev/md0 software/RAID
/dev/hda2 /dev/md1 software/RAID
/dev/hdb1 /dev/md0 software/RAID
/dev/hdb2 /dev/md1 software/RAID
/dev/md0 /boot ext3
/dev/md1 VOLGROUP00 LVM PV
LogVol00 SWAP
LogVol01 /home ext3
LogVol02 / ext3
The Windows user in me wants to be able to verifty that there are indeed two identical copies here, but from my limited knowledge I don't know how to browse the contents of my second hardrive. Everything seems to work by being mounted on something else. How can I verifty that I have done this correctly? /etc/fstab verifies LOgVol01 and LogVol02 but not LogVol00 which is the swap. Is this normal for the swap space not too show up there? It also verifies /dev/md0 but not /dev/md1. Is this because it is a Logical Volume Group or does this indicate there is something wrong with my setup?
final question. I want to test this by unplugging my first hard drive to simulate a failure. what can i expect will happen here? does my bios have to be setup to try to boot from the second drive after the first, and then failing finding the first drive it will just boot from the second? But the RAID is configured to operate on two drives, so won't there now be a misconfiguration that might stop things from working? Maybe i'm missing something here.
Not sure where to post this so i decided to post it here.
I have two drives for RAID 1. The bios RAID and centos recognize the RAID 1. I installed CentOS, and the machine works fine with RAID 1 after installation.
Let call that two drives are drive A and drive B. When I pull off drive B from the case, and insert the other drive which same size with drive B. Then i reboot the machine. The bios RAID recognize the new drive and i rebuild new drive from bios RAID, but when at boot it stuck and gives this message:
switchchroot: mount failed: no such file or directoru
Kernel panic- not syncing: attempted to kill init!
Later, i reinserted the drive B, and reboot then it goes back to normal.
I use automatic partition in centos 5... I have two hard drive, and it looks like it auto raid everything into volgroup0? is this true?
View 0 Replies View RelatedWould this be a good setup for a VPS Serving system with 2x 500gb hard disks (up to) 8gb memory.... (Looking to use OpenVZ to create about 14-15 512mb VZ VPS's)?
Host machine to do nothing other than host the VPS's. Host O/S to be Centos 5 x64, guest O/S's to be the usual OpenVZ supported linuxes.
Make 2 software raid partitions 120mb, each
|
+- Make RAID 1, mounted at /boot
Make 2 s/w raid partitions Remainder of drive
|
+- Make 1 LVM Physical Drive, using RAID 1
|
+- Make Logical Partition, 20gb, mounted '/'
+- Make LP, Swap 16gb
+- Make LP. ext3 remainder, mounted as '/vz'
Is it important what order I should make the Logical Partitions? Should I create a /tmp partition? If so, how much?
I have probably what is the most simple thing I'm going to have to do soon, but I have never done it so I'm looking for tips of how to do it because I dont want to screw it up.
I want to copy a CentOS install from one RAID array, to another. However, I have a drive image (27GB RAID array) of the old RAID array, but the new RAID array will be larger.
How can I copy the old CentOS install, to a new array?
Quote:
Today we are going to conduct a detailed study of RAIDability of contemporary 400GB hard drives on a new level. We will take two "professional" drives from Seagate and Western Digital and four ordinary "desktop" drives for our investigation. The detailed performance analysis and some useful hints on building RAID arrays are in our new detailed article.
[url]
I could try the Software-RAID 5 of the EQ9 Server of Hetzner.
Does anyone here has experiences, how fast a hardware raid 5 compared against the software-Raid 5 is?
The i7-975 should have enough power to compute the redundnacy on the fly, so there would be a minimal impact on performance. But I have no idea.
I want to run the server under ubuntu 8.04 LTS x64.
On it a vitualisation like VMware the IO-Load could get really high.
So I've just got a server with 2xSATA raid 1 (OS, cpanel and everything in here) and 4xSCSI raid 10 (clean).
Which one do you guys think will give the best performance:
1. Move mysql only to 4xSCSI raid 10
2. Move mysql and home folder to 4xSCSI raid 10
I am in a somewhat complicated situation... I wanted to order a custom server with hardware 3Ware RAID controller but after over a month of waiting I was told the HW RAID controller, as well as any other 3Ware controller they tried, does not work with the motherboard used in the server from Fujitsu-Siemens and that they simply got a reply from FS that the controller is not certified to work with their motherboard.
So although I'd prefer a HW raid, I am forced to either choose a different webhost or setup a software RAID. The problem is, I haven't done that before and am somewhat moderately...scared
I have read a lot of the info about SW RAID on Linux that I could find through Google but there are some questions unanswered still. So I thought that perhaps some of the more knowledgeable WHT members could help me with this problem...
The server specs will be:
Core2Duo E6600 (2.4Ghz), 2GB RAM, 6-8x* 250GB SATA II HDDs, CentOS 4.4 or SuSe, DirectAdmin
* I prefer 8 HDDs (or actually 9) over 6 but I am not sure if their server chassis can hold that many HDDs, I am awaiting answer from them. They don't have any other drives beside the 250GB ones so I am limited to those.
The preferred SW RAID setup is to have everything in RAID 10, except for the /boot partition which has to be on RAID-1 or no RAID I believe, plus one drive as hot spare (that would be the 9th drive). I am quite sure they will not do the setup for me but will give me access to KVM over IP and a Linux image preinstalled on the first HDD so that I'll have a functional system that needs to be upgraded to RAID-10.
How do I do that? The big problem I see is that LILO or GRUB can't boot from a software RAID-5/10 so I will have to mount the /boot partition elsewhere. It's probably terribly simple...if you have done it before which I have not. I have read some articles on how to setup a RAID-5/10 with mdadm (e.g. [url] ) but they usually do not talk about how to setup the boot partition. Should it be setup as a small sized (100-200MB) RAID-1 partition spread over all of the drives in the otherwise RAID-10 array?
What about swap? Should I create a 4-8GB (I plan to upgrade the server RAM to 4GB in near future) RAID-1 swap partition on each of the disks or swap to a file on the main RAID-10 partitions. The second sounds simpler but what about performance? Is swapping to a file on RAID-10 array a bad idea, performance wise?
Is it possible to grow a RAID-10 array in a way similar to growing a RAID-5 array with mdadm (using two extra drives instead of one of course)? mdadm doesn't actually even mention RAID-10 despite it does support it without having to create RAID-0 on top of RAID-1 pairs if the support is in kernel, from what I know.
How often do RAID arrays break? Is it worth having RAID if a servers hard drive goes down? I was thinking it may just be a better option to just have a backup drive mounted to my system and in the even of a system failure just pop in a new hard drive, reload the OS, and then reload all my backups?
View 14 Replies View RelatedI have a new server and it is rather slow during raid 1 recovery after system installed
CPU: Intel Core2Duo E5200 Dual Core, 2.5Ghz, 2MB Cache, 800Mhz FSB
Memory: 4GB DDR RAM
Hard Disk 1: 500GB SATA-2 16MB Cache
Hard Disk 2: 500GB SATA-2 16MB Cache
root@server [~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb1[1] sda1[0]
256896 blocks [2/2] [UU]
md1 : active raid1 sdb2[1] sda2[0]
2096384 blocks [2/2] [UU]
md2 : active raid1 sdb4[2] sda4[0]
480608448 blocks [2/1] [U_]
[=======>.............] recovery = 36.7% (176477376/480608448) finish=1437.6min speed=3445K/sec
the sync speed is just 3.4Mb/second and the total hours needs to be more than 40 hours
Also the server load is very high (nobody uses it)
root@server [~]# top
top - 07:00:14 up 16:55, 1 user, load average: 1.88, 1.41, 1.34
Tasks: 120 total, 1 running, 119 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.2%si, 0.0%st
Mem: 4148632k total, 747768k used, 3400864k free, 17508k buffers
Swap: 5421928k total, 0k used, 5421928k free, 569252k cached
I am in the process of restructuring the infrastructure on our servers. I am thinking of using either RAID 5 (1 hot spare) vs RAID 10 as my 1U server has 4 HDD tray.
RAID 5 would have better capacity but RAID 10 has better overall performance. Which one do you guys go for a shared hosting server?
Is it possible to turn a non raided setup into Linux software raid, while it is live, and if it's the OS drive? Can you even software raid the OS drive remotely? I've been thinking about doing it for the redundancy (and possible slight performance boost for reads, but doing it more for redundancy). I'm using CentOS.
View 12 Replies View RelatedI want to take some data from a raid-disk (taken from a raid-1 sstem). Put it into a new system already, but this system doesn't have any raid.
When viewing "fdisk -l", it said /dev/sdb doesn't contain valid partition. Is there anyway I can mount it now? I am on CentOS 4 box
MY server configure our drives with RAID-1.
How can I check it my server configure with 3ware or software raid ?
Also please advise me how can I monitor raid configuration that my raid is working fine or no ?
I've been talking to the Planet about trading in my four and a half year old "SuperCeleron" (from the old ServerMatrix days) Celeron 2.4 GHz system for something new. As part of their current promotions, I've configured a system that looks decent:
Xeon 3040, 1 gig of RAM, 2x250GB hard disks, RHEL 5, cPanel+Fantastico, and 10 ips for $162.
Not too bad. I could bump up the ram to 2 gb for, I think, $12 more, which I'm thinking about and wouldn't mind some thoughts on. But, the thing that has me really confused is RAID. I like the idea of doing a RAID 1 setup with those two hard disks. But, the Planet wants $40/month for a RAID controller to do it. I really don't want to go over $200 a month!
Any thoughts on alternative redundancy strategies that might avoid that cost? Software RAID does not seem to be offered by the Planet, unless I can figure out how to do it after installation (is that possible?) Better ideas in general on the server?
Just curious what your thoughts are on performance:
2 SCSI Drives 10k w/RAID 1
or
4 SATA 10k w/RAID 10
Prices are not too different with 4 drives just being a tad more.
how well software raid can perform and how it compares to hardware raid. How does software raid actually work and is it worth it?
How should I look at be setting up software raid if I was going to? Would you recommend just to use hardware raid instead?
Which do you guys recommend of the following?
4x 73GB 15,000rpm SAS drives in a RAID 10
or
4x 73GB 15,000rpm SAS drives in a RAID 5 w/ online backup
any recomendations in kvm cards? its for a generic 2u server.
View 12 Replies View RelatedYou'll see that if we ping localhost or even an ip address/url it goes funky like this.
View 12 Replies View Related