similar to: poor read performance

I just tried this with CentOS 5.3 as well, and got exactly the same symptoms and dmesg output. (As a point of comparison, Ubunu 8.04 on my work laptop is able to access the drive.) Obviously "not detected" is a misapprehension, though I'm puzzled why "lsusb" doesn't show it. The device is there even though the partition table can't be read. ---------- Forwarded

I have a Dell PowerEdge 2950 and am looking to add more storage. I know a lot of factors can go into the type of answer given, but for present and future technology planning, should I look for a rack of SATA, SCSI, or fibre channel drives? Maybe I'm dating myself with fibre channel, and possibly SCSI? I may be looking to add a few TB now, and possibly more later. What are people

Dear list, I thought I'd just share my experiences with this 3Ware card, and see if anyone might have any suggestions. System: Supermicro H8DA8 with 2 x Opteron 250 2.4GHz and 4GB RAM installed. 9550SX-8LP hosting 4x Seagate ST3250820SV 250GB in a RAID 1 plus 2 hot spare config. The array is properly initialized, write cache is on, as is queueing (and supported by the drives). StoreSave

Help please- I am running 3.3.1 on Centos using a 10GB network. I get reasonable write speeds, although I think they could be faster. But my read speeds are REALLY slow. Executive summary: On gluster client- Writes average about 700-800MB/s Reads average about 70-80MB/s On server- Writes average about 1-1.5GB/s Reads average about 2-3GB/s Any thoughts? Here are some additional details:

See http://rwmj.wordpress.com/2014/11/23/mapping-files-to-disk/

HI All, I have a dilemma and I would appreciate advice 1. Get a good size case, mobo, processor, etc and put 8 hard drives it in and RAID them. (yes an 8 port SATA mobo). Running CentOS. or 2. Get an eSATA enclosure that has room for 8 or 10 drives and just connect it to box? I know that RAID is not a full proof backup, but I am looking for a solution to store all of my data, projects, music,

I run a decent amount of 3ware hardware, all under centos-4. There seems to be some sort of fundamental disagreement between ext3 and 3ware's hardware RAID5 mode that trashes write performance. As a representative example, one current setup is 2 9550SX-12 boards in hardware RAID5 mode (256KB stripe size) with a software RAID0 stripe on top (also 256KB chunks). bonnie++ results look

Does *not* incorporate changes suggested by Pino yet. Rich.

On 4/22/20 8:53 AM, Christopher Wensink wrote: > I had an 8 TB External USB disk plugged into the system, that I had been > using for additional space for backups, I was under the impression that > sda, sdb, sdc, and sdd were the four disks on the raid controller card, Not exactly.? If you have a RAID5 array, then you have one volume spread across the physical disks.? You can then

Hello fellow sysadmins! I've assembled a whitebox system with a SuperMicro motherboard, case, 8GB of memory and a single quad core Xeon processor. I have two 9650SE-8LPML cards (8 ports each) in each server with 12 1TB SATA drives total. Three drives per "lane" on each card. CentOS 5.2 x86_64. I'm looking for advice on tuning this thing for performance. Especially for the

I've got a Centos 4 box at work, where I noticed a pile of old kernels lying around and no longer needed. I did "rpm -qa | grep -y kernel > list" then edited the list to remove from it the newer kernels, then "yum remove `cat list`". Yum has come up with a list of 71 packages it wants to remove, even though there were only 33 kernel-related RPMs in the list. this

hi all We have a rh linux server connected to two HP SAN controllers, one an HSV200 (on the way out), the other an HSV400 (on the way in). (Via a Qlogic HBA). /etc/multipath.conf contains this : device { vendor "(COMPAQ|HP)" product "HSV1[01]1|HSV2[01]0|HSV300|HSV4[05]0" getuid_callout "/sbin/scsi_id -g -u -s /block/%n"

The number of threads has nothing to do with the number of cores on the machine. It depends on the I/O, network speed, type of workload etc. We usually start with 32 threads and increase if necessary. You can check the statistics with: watch 'cat /proc/net/rpc/nfsd | grep th? Or you can check on the client nfsstat -rc Client rpc stats: calls retrans authrefrsh 1326777974 0

On 11/23/20 10:46 AM, Simon Matter wrote: >> Hi, >> >> I want to replace my hard drives based SW RAID-1 with SSD's. >> >> What would be the recommended procedure? Can I just remove one drive, >> replace with SSD and rebuild, then repeat with the other drive? > > I suggest to "mdadm --fail" one drive, then "mdadm --remove" it.

I'm trying to create a 500GB lv volume on a 500GB physical volume, but can't: [root at francois-pc ~]# pvscan PV /dev/sdd VG freenas lvm2 [500.00 GB / 500.00 GB free] PV /dev/sdc VG thecus lvm2 [1010.00 GB / 910.00 GB free] PV /dev/mapper/ddf1_RAIDp2 VG VolGroup00 lvm2 [931.25 GB / 0 free] Total: 3 [2.38 TB] / in use: 3 [2.38 TB]

I believe what I am going to write is a bug report. When I finaly did # btrfs send -v /mnt/adama-docs/backups/20130101-192722 | btrfs receive /mnt/tmp/backups to migrate btrfs from one partition layout to another. After a while system keeps saying that "Too many open files in system" and denies access to almost every command line tool. When I had access to iostat I confirmed the

How do I find out why df -k is taking soo long to respond only sometimes? -- Asif Iqbal PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing?

I am familiar with centos and this forum, and have some rhel / centos questions. Therefore I'm asking the question here I am about to install rhel4.5 on a hp dl380 with 4 disc's. The standard rhel installation installers all in one partition? Will there be any advantage of splitting the file system up? What would be a good recommended partition table for a server running scripts

Hi, we would like to establish a small Lustre instance and for the OST planning to use standard Dell PE1950 servers (2x QuadCore + 16 GB Ram) and for the disk a JBOD (MD1000) steered by the PE1950 internal Raid controller (Raid-6). Any experience (good or bad) with such a config ? thanxs, Martin

I may have asked about this before, but I can't find any records of so doing in my saved mail (which includes almost everything I ever read or write): All of a sudden, I am not getting flash drives automatically mounted in CentOS 5.3 with GNOME - they are recognized by the hardware, but there seems to be a (new?) problem with the maps. Here's the tail end of dmesg: usb 1-10: new high