what are peoples opinions on running ext3 in writeback journal mode when the filesystem resides on a BBU (battery backup unit) RAID array. The BBU retains data cached on the RAID card, but all the delayed writes from writeback mode may not even have gotten to the RAID card. Am I correct on that logic?
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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]
We're considering deploying a large server that will have 8x 500GB drives in a RAID-10 config. I intend to use a 3ware 9650SE w/ BBU along with A/B power to each of the PSU's.
My question is... since this will return into a 2TB array/partition, in event of a crash (kernel panic, etc -- I expect a power outage will be very, very rare if at all) what do you guys think the fsck time would be? In my experience a RAID BBU significantly drops it, sometimes to the point of no manual fsck required, but in event of a manual fsck shouldn't the BBU be able to provide more consistent data (less errors) and therefore a much shorter fsck? Maybe just recovering the journal?
have a centos 5.1 box but not sure if i have ext2 or ext3 on the drives? basically trying to disable the file system check if there's a hard boot, which i wouldn't risk if its ext2 but will do if its ext3.
View 4 Replies View RelatedOS: Debian etch
partition type: EXT3
I was unziping from network 4gb file to my server and server crashed. When I got it back up partition has allocated 4gb of space, but there is no file I cannot reallocate it.
/dev/hda6 67G 63G 437M 100% /home
Like you can see above 4gb is allocated but it is not used, so what can i do?
I wanted to mount a Usb portable drive of some data I have inside my Linux server and make them read on my Windows xp.
The drive has been formatted as ext3 and it just won't show in "my computer" inside Windows unless I reformat it again as ntfs.
The same turns around if if I format as ntfs, and i can't mount it under linux with the message "mount: unknown file system type 'ntfs'"
Our server with raid 10 has had a failed hdd (which was replaced) and a
corrupt ext3 filesystem.
The server is now booted with Knoppix but drives will not mount. All we are trying to at this point is salvage as much data as we can.
i have a problem with my server it wan't boot, i get the following error on /tmp
fsck.ext3 e2fsck_read_bitmaps illegal bitmap block
how can i fix?
kernel: EXT3-fs error (device loop0): ext3_lookup: unlinked inode 12286 in dir #2
kernel: EXT3-fs error (device loop0): ext3_journal_start_sb: Detected aborted journal
EXT3-fs error (device loop0): ext3_lookup: unlinked inode 12286 in dir #2
some errors I get on my dedicated server? I also got errors like these when I deleted inside a folder a large number of files and after running every time 'du' it shows kernel errors.
---------
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299439] EIP is at ext3_clear_inode+0x42/0xa0 [ext3]
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299459] eax: d73d9c2c ebx: d73d9b94 ecx: 00000000 e dx: ffff9eff
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299479] esi: d73d9c2c edi: 00000000 ebp: 0000003e e sp: f7f4feb4
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299499] ds: 0068 es: 0068 fs: 00d8 gs: 0000 ss: 006 8
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299520] Process kswapd0 (pid: 162, ti=f7f4e000 task=f79ab 550 task.ti=f7f4e000)
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299540] Stack: d73d9c2c 00000000 f7f4fef0 c01ec2ff f7f4fe f0 d73d9c34 d73d9c2c c01ec65a
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299585] 00000080 de2652b8 00000080 f7f4fef0 c01ec8 a5 00000000 00000080 d73d9e18
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299628] e3c8dc34 0000e54c 00000094 f7ffea80 000000 d0 c01bedfd 0000580f 00000000
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299671] Call Trace:
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299699] [<c01ec2ff>] clear_inode+0x9f/0x150
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299726] [<c01ec65a>] dispose_list+0x1a/0xe0
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299751] [<c01ec8a5>] shrink_icache_memory+0x185/0x260
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299779] [<c01bedfd>] shrink_slab+0x11d/0x180
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299812] [<c01bf27a>] kswapd+0x35a/0x450
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299849] [<c0195d80>] autoremove_wake_function+0x0/0x50
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299880] [<c01bef20>] kswapd+0x0/0x450
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299900] [<c0195bca>] kthread+0xba/0xf0
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299921] [<c0195b10>] kthread+0x0/0xf0
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
server kernel: [358873.299945] [<c015f6e7>] kernel_thread_helper+0x7/0x10
Message from syslogd@ at Wed Jul 16 16:30:26 2008 ...
Is 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 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
how to know in which mode php running ? CGI or ISAPI
View 2 Replies View RelatedI currently have one server running PHP in suPHP mode. One of my friend told me that if i change the PHP to Apache Mode, this would decrease my server load a lot and thus give more performance.
Anyone can tell me what mean changing PHP to Apache mode? Is that something i can do from WHM? Will this affect the domains currently hosted on my server?
What is the best option in the php setting does keeping the php function safe mode on or off?
View 12 Replies View Relatedi need to enable php safe mode on for my joomla and i came across this
Quote:
When the php safe mode is turned off globally by default at our server end, you can still override the setting to turn it ON for only your domain by just insert the following line inside the ".htaccess" file (at Linux server):
Code:
php_value safe_mode "1"
my joomla .htaccess file:
Quote:
##
# @version $Id: htaccess.txt 10492 2008-07-02 06:38:28Z ircmaxell $
# @package Joomla
# @copyright Copyright (C) 2005 - 2008 Open Source Matters. All rights reserved.
# @license http://www.gnu.org/copyleft/gpl.html GNU/GPL
# Joomla! is Free Software
##
#####################################################
# READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE
#
# The line just below this section: 'Options +FollowSymLinks' may cause problems
# with some server configurations. It is required for use of mod_rewrite, but may already
# be set by your server administrator in a way that dissallows changing it in
# your .htaccess file. If using it causes your server to error out, comment it out (add # to
# beginning of line), reload your site in your browser and test your sef url's. If they work,
# it has been set by your server administrator and you do not need it set here.
#
#####################################################
## Can be commented out if causes errors, see notes above.
Options +FollowSymLinks
#
# mod_rewrite in use
RewriteEngine On
########## Begin - Rewrite rules to block out some common exploits
## If you experience problems on your site block out the operations listed below
## This attempts to block the most common type of exploit `attempts` to Joomla!
#
# Block out any script trying to set a mosConfig value through the URL
RewriteCond %{QUERY_STRING} mosConfig_[a-zA-Z_]{1,21}(=|\%3D) [OR]
# Block out any script trying to base64_encode crap to send via URL
RewriteCond %{QUERY_STRING} base64_encode.*(.*) [OR]
# Block out any script that includes a <script> tag in URL
RewriteCond %{QUERY_STRING} (<|%3C).*script.*(>|%3E) [NC,OR]
# Block out any script trying to set a PHP GLOBALS variable via URL
RewriteCond %{QUERY_STRING} GLOBALS(=|[|\%[0-9A-Z]{0,2}) [OR]
# Block out any script trying to modify a _REQUEST variable via URL
RewriteCond %{QUERY_STRING} _REQUEST(=|[|\%[0-9A-Z]{0,2})
# Send all blocked request to homepage with 403 Forbidden error!
RewriteRule ^(.*)$ index.php [F,L]
#
########## End - Rewrite rules to block out some common exploits
I have a script that needs safe mode off to run, the script writers have said safe mode is disabled as default and not required and even disabled in php 6
Now I'm not to fimular with Safe mode, all I know is most scripts are wrote to work with this on
Should i switch safe mode on or off . Right now i am using it as on some one told me if i switch it off then server can easily hack but becoz i switch it on im having too much problem specially users of sites having problem of uploading and wordpress also have issue and some more script what you say what should i do?
View 9 Replies View Relatedhow can i make "safe mode on/off" using .htaccess?( in SharedHosting )
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