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23

Check for files on located under mount points. Frequently if you mount a directory (say a sambafs) onto a filesystem that already had a file or directories under it, you lose the ability to see those files, but they're still consuming space on the underlying disk. I've had file copies while in single user mode dump files into directories that I couldn't ...


15

The conversion of a SCSI chassis DL380 G4 to the SAS chassis is possible, but not at all practical. It requires a bezel change, backplane modification, a new drive cage, a Smart Array P600 RAID controller (or SAS/SATA HBA) and will be severely crippled in performance. In addition, it can only accommodate 2.5" small-form-factor 1st generation SAS and SATA ...


12

2.5" hard drives have a much smaller platter diameter and thus there is a smaller mass that must be moved while friction is reduced as well. On the other hand, the operating range of the slider (which carries the heads) is smaller, which has a positive impact on access time if you compare 3.5" and 2.5" at equal rotation speeds and mechanical components. A ...


11

This has been covered here... See the related links on the right pane of this question. Right now, the market conditions are such that you should try to use SAS disks everywhere you can. Enterprise SAS disks are your fastest and most resilient rotating media available at 10,000 and 15,000 RPM. Performance-optimized Nearline or Midline SAS are usually ...


10

Old NeXT hardware. SWOON! Getting a SCSI2 -> SCSI 1 adapter should be trivial. There were both internal and external varieties. Google is your friend. For some reason I thought the "newer" slabs should be SCSI2 but it's been a long time. You still have to terminate the scsi chain. Keep to addresses 0-7. Further just Googling for "scsi-2 pci card" comes up ...


9

SAS is largely an "enterprise" tech whereas USB is most definitely not (at least as far as storage goes, anyway). I'm guessing this is why you haven't found any suitable adapters. That said, you're going about this the wrong way. With a good backup regimen, you dont need the original hardware. So, get a good backup system in place and this issue is ...


8

The other guys have answered very well but I have a pet-subject that I like to roll out whenever this kind of thing raises its head - what's known as 'Duty Cycle'. 'Duty Cycle' is the workload that the disk manufacturer anticipates the disk will use and it designed to work most reliably at. For instance many 'enterprise' disks have a 100% 'duty cycle' - ...


8

The Zeus IOPS SSD (used by Oracle storage and others) uses SAS interfaces at 3G or 6G. http://www.stec-inc.com/product/zeusiops.php In addition, the Sandisk/Pliant line has SAS 6G interfaces. http://www.sandisk.com/business/industries/enterprise/ Other options are listed here: http://www.storagesearch.com/ssd-sas.html


7

"Near-line" is a marketing term for "7.2K RPM drives not designed for 24/7/365 continual usage". Using them in such a role will result in an increased failure rate compared to drives designed to be used flat out for years at a time. SAS vs SATA, in many cases there are little meaningful differences between the two bus specs, but SAS was designed for ...


7

I've built many of these systems... Your issue is an easy fix. This is an old server, so I wouldn't invest much time, however the HP ProLiant DL380 G4 was an odd unit. I presume you have a SCSI model with 6 U320 SCSI drive bays in the front. In order to resolve your situation, you should understand that the server has an onboard Smart Array 6i RAID ...


7

The three values stand for channel, SCSI target ID, and LUN. The dashes act as wildcards meaning "rescan everything" A quick google search turns up this RHEL doc (and dozens of other answers) This is the same command described in Section 7, “Adding a Storage Device or Path” to add a storage device or path. In this case, however, the channel number, SCSI ...


6

In the Red Hat storage administration guide, the method you mentioned is there, along with some other options which you might prefer. echo "- - -" > /sys/class/scsi_host/hosth/scan [...] This procedure will add LUNs, but not remove them. There's also the less arcane /usr/bin/rescan-scsi-bus.sh, which has the advantage that it can also remove ...


6

Shoe-shining refers to the tape drive stopping and rewinding due to an empty data buffer or inconsistent incoming data stream. This was a problem with older DLT drives. LTO drives shouldn't experience shoeshining. The LTO format/standard was partially designed to eliminate this behavior. HP drives, in particular, have a variable write speed to help reduce ...


6

To add a little bit to Stephen Thompson's answer which was good. Currently the largest SAS 2.5" drives are 146 GB for 15k, and 300 GB for 10k. One reason why the SAS 3.5" disks have relatively poor density, is that the platters themselves are far from filling the case, closer to 2.5" size actually. This is AFAIK due to problems with larger platters ...


6

For the sake of simplicity when I say "SCSI" I'm talking about "traditional" SCSI and SAS So, on the most basic level SCSI drives will be more reliable simple because they are built better. They are designed and priced to be put into high end machines - primarily servers where they will get a lot of abuse and quite possibly run 24/7/365 for 5-7 years. They ...


6

The Atlas series was a noisy drive. There are two possible reasons for clicking with them. They have a notoriously noisy park mechanism which is probably what you've been hearing for all this time. The second thing that the Atlas series did was click when the drive hit either extreme point of extension. The Seagates to my knowledge didn't have the same ...


5

Given equivalent sizes, the SSD's will give you vastly more I/O operation performance than the SATAs will. Both are fast enough to saturate the SATA connection given the right I/O access patterns, though the SSD's will deliver it more often. As with most performance comparisons, it depends on what you're doing with them. At sizes like these I suspect ...


5

It's always nice to see a new serverfault user that's already got the right answer in mind :) Basically what you suggest is spot-on, there are some SCSI-to-USB devices out there (I think Adaptec did their own at one point) that may make it a bit more portable but essentially that's exactly the way to do it.


5

Such cables do exist, though I don't know of any enclosures. The problem with server SCSI hard-drives is that nearly all of the time they were attached to a RAID card, and that makes them not universally mountable without the family of RAID card they were originally attached to. If they're old enough, finding the right hardware to get at the data can be ...


5

I do hope you have more than a bare blade server. It's completely useless without the accompanying chassis and interconnects. The full specifications for the server are available here. These are the only hard drive options that will work for your server. They are all old-school 3.5" parallel SCSI disks. The BL20p G3 server can only accept two hard disks. ...


4

Touching upon slightly newer options, it may be possible to use a SCSI to iSCSI bridge, which would allow you to hit a target on a standard RAID. If you used a target which supported snapshots, you would get backup and restore thrown in for free. Google provided the RSI-iSCSI-C by Rancho SysTech Inc Intended use:


4

Taking a few minutes to go read the Wikipedia article on SCSI won't be a bad idea. The "primary" and "secondary" are referring to the IDE controllers. You're not going to get SCSI disks to show up there. It sounds like you've got fixed-mounted drives rather than hot-plug. If I'm wrong then this needs to be edited. That machine has an integral SCSI ...


4

See: http://h18000.www1.hp.com/products/quickspecs/13572_na/13572_na.html If you have a PCI Express port in your server, you should use: 412911-B21 If you only have PCI-X slots, use: 374654-B21


4

Adapters are available to convert from a molex power connector to the SATA connector, with the caveat that the molex connectors don't have the 3.3 volt feed that's technically part of the SATA power spec. I haven't personally run across any drives that actually need the 3.3V connection, but you'll want to check with your specific drives.


4

On recent kernels the /proc/scsi is being "migrated" to sysfs. You can recompile the kernel and enable the CONFIG_SCSI_PROC_FS: legacy /proc/scsi/ support to the scsi subsystem, or see if something under /sys/class/scsi_host and other sysfs dirs have what you need. The legacy support is a good route if you have many tools that rely on /proc/scsi to work.


4

I agree with OldTroll's answer as the most probable cause for your "missing" space. On Linux you can easily remount the whole root partition (or any other partition for that matter) to another place in you filesystem say /mnt for example, just issue a mount -o bind / /mnt then you can do a du -h /mnt and see what uses up your space. Ps: sorry for ...


4

For SATA, you need to be careful about using a consumer drive if you are building a RAID array. Some power saving features and in the case of Western Digital, some of their SATA drives have a "deep recovery" process when an error is detected. These can cause a SATA RAID member to be dropped or marked as failed if it is unresponsive beyond the timeout ...


4

No. You're buggered. Either: Get a disk of the same model as the one you have, formatted the same (sometimes OEM disks can have a slightly different format to ones with generic firmware) Get a 146GB disk and be prepared to waste half of the capacity. Get a disk with the array manufacturer's firmware, which will be set up so it can act as a drop in ...


3

This won't help you now, but in the past I've taken to leaving around 500~700Mb leeway at the end RAID sets, where we haven't been able to procure enough spares of the same model and the HBA won't accept drives of a larger size. It's less of an issue nowadays - we only tend to run into it when using the max configurations in blades.


3

On Linux 2.4 you can force a scsi bus rescan by sending 'echo 1' to one of the /proc entries. I always looked it up in the SCSI_HOWTO document. I can look it up if needed. It sounds like the drive is going offline. Have you tried the scsitur (test unit ready) or the scsinq command ?



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