Questions tagged [storage]
Primarily questions about disk storage, sometimes questions about application storage or cloud storage. Always questions about storing data.
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What are the different widely used RAID levels and when should I consider them?
This is a Canonical Question about RAID levels.
What are:
the RAID levels typically used (including the RAID-Z family)?
deployments are they commonly found in?
benefits and pitfalls of each?
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Are SSD drives as reliable as mechanical drives (2013)?
SSD drives have been around for several years now. But the issue of reliability still comes up.
I guess this is a follow up from this question posted 4 years ago, and last updated in 2011. It's now ...
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Incredibly low disk performance on HP ProLiant DL385 G7
As a test of the Opteron processor family, I bought a HP DL385 G7 6128 with HP Smart Array P410i Controller - no memory.
The machine has 20GB ram
2x146GB 15k rpm SAS + 2x250GB SATA2, both in Raid 1 ...
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answer
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Hosting a ZFS server as a virtual guest
I'm still new to ZFS. I've been using Nexenta but I'm thinking of switching to OpenIndiana or Solaris 11 Express. Right now, I'm at a point of considering virtualizing the ZFS server as a guest within ...
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How exactly does a SAS SFF-8087 breakout cable work? + RAID/connection questions
Please let me know if my question does not makes any sense as I am not sure if I am interpreting it correctly from my thoughts due to my lack of technical knowledge on this.
If I am using a ...
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29
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3
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Linux - real-world hardware RAID controller tuning (scsi and cciss)
Most of the Linux systems I manage feature hardware RAID controllers (mostly HP Smart Array). They're all running RHEL or CentOS.
I'm looking for real-world tunables to help optimize performance for ...
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6
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Why is Enterprise Storage so expensive?
This is a Canonical Question about the Cost of Enterprise Storage.
See also the following question:
What's the best way to explain storage issues to developers and other users
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24
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Storing a million images in the filesystem
I have a project that will generate a huge number of images. Around 1,000,000 for start. They are not large images so I will store them all on one machine at start.
How do you recommended on ...
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5
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What is the difference between SAN, NAS and DAS?
What is the difference between SAN, NAS and DAS?
sevugarajan
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4
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what is exactly an URE?
I have been looking into RAID5 Vs RAID6 lately and I keep seeing that RAID5 is not secure enough anymore because of the URE ratings and increasing size of the drives. Basically, most of the content I ...
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7
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Disabling RAID feature on HP Smart Array P400
I'm planning to use ZFS on my system (HP ML370 G5, Smart Array P400, 8 SAS disk). I want ZFS to manage all disks individually, so it can utilize better scheduling (i.e. I want to use software RAID ...
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BBWC: in theory a good idea but has one ever saved your data?
I'm familiar with what a BBWC (Battery-backed write cache) is intended to do - and previously used them in my servers even with good UPS. There are obvously failures it does not provide protection for....
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Probability of Blade Chassis Failure
In my organisation we are thinking about buying blade servers - instead of rack servers. Of course technology vendors also make them sound very nice. A concern, that I read very often in different ...
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Why are enterprise SAS disk enclosures seemingly so expensive?
I will begin by stating that I do not believe this is a duplicate of Why is Enterprise Storage so expensive?.
My question is specifically about SAS drive enclosures, and justifying their expense.
...
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ZFS Data Loss Scenarios
I'm looking toward building a largish ZFS Pool (150TB+), and I'd like to hear people experiences about data loss scenarios due to failed hardware, in particular, distinguishing between instances where ...
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Which Distributed File System as a backend for Cloud Computing?
I have a basic cloud running on Ubuntu Server (9.04) and Eucalyptus. Walrus (Eucalyptus' API compatable S3 implementation) stores files by on the cloud controller. However each of the other 4 server ...
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Is there a way to do something like LVM over NFS?
I realize that since NFS is not block-level, LVM can't be used directly.
However: is there a way to combine multiple NFS exports (from, say, 3 servers) into one mount point on a different server?
...
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RAID5 on SmartArray P410i online resize
I have P410i+256M Cache without battery backup.
My RAID5 was build over 3*136GB disks, now all disks were replaced to a 3*300GB array.
How can I extend it to use the whole space?
HPacucli doesn't ...
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3
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What are the merits of SAS vs SATA drives? [closed]
What are the merits of buying SAS drives over SATA drives, or vice versa?
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Is it safe to use consumer MLC SSDs in a server?
We (and by we I mean Jeff) are looking into the possibility of using Consumer MLC SSD disks in our backup data center.
We want to try to keep costs down and usable space up - so the Intel X25-E's ...
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Do I need to RAID Fusion-io cards?
Can I run reliably with a single Fusion-io card installed in a server, or do I need to deploy two cards in a software RAID setup?
Fusion-io isn't very clear (almost misleading) on the topic when ...
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Are RDX removable disks a good replacement for LTO tape?
Over a period of three weeks, I experienced six complete failures of LTO-1 and LTO-2 tape drives at client sites. Some had failed mechanisms. Others lost the ability to write reliably. These were HP ...
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8
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RAID-5: Two disks failed simultaneously?
We have a Dell PowerEdge T410 server running CentOS, with a RAID-5 array containing 5 Seagate Barracuda 3 TB SATA disks. Yesterday the system crashed (I don't know how exactly and I don't have any ...
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Battery Backed Write Cache
I recently got some U server price quotes and some of them include BBWC:
What exactly does it do?
Is it just for RAID configurations?
If there is a power malfunction, isn't the data loss inevitable?...
- 1,226
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Is calculating IOPS for ZFS RAIDZ different then calculating IOPS for RAID5 & RAID6?
When calculating IOPS for traditional RAID arrays, one could use the following formula (Borrowed from Getting The Hang Of IOPS v1.3 on Symantec Connect):
Ieffective = (n * Isingle) / (READ% + (F * ...
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What are the differences between consumer grade SSDs and the much more expensive enterprise SSDs?
I am in need of a terabyte or so of storage space for Lucene indices on a testing server. I'm having a hard time differentiating between disks like the Samsung 840 evo for about $450 vs SSDs with ...
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2
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HP ACU shows parity initialization failed on Smart Array controller
I put in a new drive due to a hard drive failure. When the rebuild got to 100%, the controller fails and I need to reboot the server to bring it online. I had to do this about three times and it ...
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13
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Windows 2008: WinSXS directory growing uncontrollably, blocking server
I run a (remotely hosted) virtual Server with Windows 2008 Server for a client.
Initially, it had 10 GB of space.
During the course of a few weeks - during which nothing was done on the machine ...
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How to monitor the hard disk status behind Dell PERC H710 Raid Controller with CentOS 6?
I have a Dell server running CentOS 6 using PERC H710 Raid Controller card with Raid 5 setup and I want to monitor the hard disk failure/working status behind the Raid Controller.
Then I should be ...
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Do you lose everything when you have a hard disk failure in a multi-hard disk LVM that does NOT use RAID?
I'm debating about using LVM for a media/file server because I would like to combine multiple physical hard disks into one volume. I do not wish to use any RAID in my LVM so my question is:
If one ...
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How do I get my HP servers to email me when a drive fails?
Ideally, with as simple of install as possible and without requiring rebooting the servers. Mostly for DL380 G5's if it helps.
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/home/vhosts/ or /var/www/
Some web servers I've come across use /home to store the site files:
/home/vhosts/www.example.com/
Others use /var like:
/var/www/www.example.com/
What's more clean and "Linuxy"? Should we all be ...
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CentOS 6 doing lots more IO than CentOS 5
I'm benchmarking an application on two identical servers, one is Centos 5.8 and the other is Centos 6.2. My application is running much slower (50% or less) on the Centos 6.2 machine.
In attempting ...
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Hadoop JBOD disk configuration on HP Smart Array 410/i disk controller
I'm in a evaluation phase of some hw that could be used for setting up a hadoop cluster. This hw is refurbished (hp G6 servers w/ Smart Array 410/i controller) and probably we should/must use it... we ...
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MegaRAID JBOD substitute
It seems that certain MegaRAID chips don't support JBOD (unfortunately).
I've read online that to make these controllers act as a pass-through, I should configure the disks in RAID0.
What RAID0 ...
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What is the use-case for NAS on a mid-to-high end storage array?
Many large storage vendors (EMC, NetApp, etc) provide storage equipment that does NAS in addition to FCP, FCoE, or iSCSI.
When would it be appropriate to use the NAS functionality of these boxes? In ...
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6 Disk Raid 1+0
I have an HP Smart Array P400i raid controller, with 6 disks, working in a RAID 1+0. This is what it looks like:
Mirror Group 0:
physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SAS, 72 GB, OK)...
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SAS enclosure doesn't restart - MSA60
I just inherited a HP StorageWorks MSA60 (this is a direct-attach SAS enclosure).
I had to move it to another shelf so I turned off the computer which was using it. I also pulled the 2 power cords off ...
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Prevent owner to change permissions on network share
we have a Sun Storage Appliance (7110) with a SMB/CIFS share configured. It is joined to our Active Directory. What I am trying to accomplish is: ordinary Domain Users (builtin AD-group) should have ...
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ZFS vs XFS
We're considering building a ~16TB storage server. At the moment, we're considering both ZFS and XFS as filesystem. What are the advantages, disadvantages? What do we have to look for? Is there a ...
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Does an unplugged hard drive used for data archival deteriorate?
If I were to archive data on a hard drive, unplug it, and set it on a (not dusty, temperature-controlled) shelf somewhere, would that drive deteriorate much?
How does the data retention of an ...
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What's the best way to explain storage issues to developers and other users
When server storage gets low developers all start to moan, "I can get a 1 TB drive at Walmart for 100 bucks, what's the problem".
How can the complexities of storage be explained to developers so ...
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Distributed Storage Filesystem - Which one/Is there a ready to use product?
With Hadoop and CouchDB all over in Blogs and related news what's a distributed-fault-tolerant storage (engine) that actually works.
CouchDB doesn't actually have any distribution features built-in, ...
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What is the difference between a HBA card and a RAID card?
I thought I knew the difference between HBA and RAID.
In my mind, HBA is offloading from the main motherboard/CPU and is simply JBOD... usually has an external SAS ports, whilst a RAID card does the ...
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How effective is LSI CacheCade SSD storage tiering?
LSI offers their CacheCade storage tiering technology, which allows SSD devices to be used as read and write caches to augment traditional RAID arrays.
Other vendors have adopted similar technologies;...
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HP storage arrays - multiple channels?
Our SQL server is becoming pretty heavily loaded, and all indications point to the disk channel being the bottleneck. The current HP server has a fairly low-end array card, and we're looking to ...
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SAS vs. Nearline/MDL SAS - What is the difference?
As subject I guess, looking at SAN's and most vendors offer 10k or 15k "proper" SAS drives, many also offer 7.2k MDL/Nearline SAS drives.
Does anyone have an authoritative explanation of the ...
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KVM guest io is much slower than host io: is that normal?
I have a Qemu-KVM host system setup on CentOS 6.3. Four 1TB SATA HDDs working in Software RAID10. Guest CentOS 6.3 is installed on separate LVM. People say that they see guest performance almost equal ...
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9
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Home-brew automatic tiered storage solutions with Linux? (Memory -> SSD -> HDD -> remote storage)
Related to this question about using an SSD for system and HDD for data, except I would like my system to do this automatically...
Is it possible to have several layers of storage and push items ...
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10
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Software RAID underneath ESXi datastore
I'm building an virtual environment for a small business. It is based around a single ESXi 5.1 host, which will host half a dozen or so VMs. I'm having some doubts regarding how to implement the ...
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